Project code - Statistics

The table below shows the project code of the public data and the related number of fits files.

# Project code #of FITS files Title Abstract Scientific keyword Category Release date
1 2011.0.00548.S 0 Resolving FU Ori v2 The FU Ori phase is likely vital to the build up of the mass of stars. However, little is known about the mass distribution in the disks surrounding these objects. Particularly, FU Ori itself is undergoing rapid accretion due to gravitational instability. Our proposed obesrvations take advantage of the opportunity to measure the link between the inner disk instability and the outer disk feeding of this instability through short, resolved, multi-wavelength continuum observations. We also may potentially derive other disk properties through the detection of a variety of molecular species. These observations are vital to understanding this key process in star formation. Disks around low-mass stars Disks and planet formation 2014-02-25T16:59:00.000
2 2021.1.00546.S 35 Unveiling the kinematics of a highly dense prestellar core with substructures at 1000 au scale Prestellar cores (PSC) are self-gravitating dense and cold structures within molecular clouds where future stars are born. They are expected, at the stage of transitioning to the protostellar phase, to harbor centrally concentrated dense (sub)structures that will seed the formation of a new star or the binary/multiple stellar systems. Characterizing this critical stage of evolution is key to our understanding of star formation. In a rare detection, recently dense 'kernel'(~2000 au) and substructures are reported towards an Orion PSC G205-M3. However, it is unclear how the structure and substructures form in the prestellar core (PSC), and the role of gravity and turbulence in producing the substructures. To this end, we propose high-resolution ALMA observation using N2H+ and N2D+ to measure the temperature profile, kinematics, and velocity dispersion in the central dense region of the PSC. These molecules do not suffer depletion in the dense region, and using the high-resolution ALMA observation for the first time we will be able to unveil the fragmentation mechanism and kinematics of the PSC at the onset of collapse and star formation. Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2023-09-29T06:36:24.000
3 2013.1.00266.S 14 HMSFSiO We propose ALMA high-angular resolution and high sensitivity observations of SiO v=1, J=2-1 maser lines toward new SiO maser sources of 2 high-mass star-forming regions, G19.61-0.24A and G75.78+0.34 which are detected by the Korean VLBI Network single dish telescope. Through the ALMA observations, we investigate the exact positions and spatial distributions of SiO v=1, J=2-1 maser emission. We also expect to investigate the inner part of jets/outflows which regions are playing an important role for launching and collimating the jets/outflows probably related with rotating accretion disks close to the central protostars. In addition, the observational results of several transitions of CH3OH masers, SiO thermal emission, and continuum etc. are compared with those of SiO masers. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2016-11-21T19:11:20.000
4 2021.1.00128.L 1087 AGE-PRO: the ALMA survey of Gas Evolution in PROtoplanetary disks We propose a Large Program designed to systematically trace the evolution of gas disk mass and size throughout the lifetime of protoplanetary disks, using a well-defined sample of 30 disks between 0.1-10 Myr old. Gas is the dominant mass constituent of protoplanetary disks. Its structure and evolution profoundly impact every major step of planet formation: planetesimal formation, accretion of planetary atmospheres, and migration of planets. Yet, we do not have a basic understanding of how the gas disk evolves and what mechanism drives the global evolution. This program will provide the first homogeneous and sensitive survey to constrain the evolution of the mass and size of gas disks at three evolutionary phases: the embedded disk phase, the middle-age, and the end of the disk lifetime. By combining deep observations of CO isotopologues and N2H+, we will improve the accuracy of current mass measurements by a factor 10-20, and size measurements by a factor of 5. The results will provide fundamental insights into the global evolution of protoplanetary disks, and provide a key legacy dataset to test current main theories of disk evolution and planet formation. Disks around low-mass stars Disks and planet formation 2023-04-21T13:01:38.000
5 2021.1.00045.S 0 The surface magnetic field of AGB stars: Zeeman measurements of atmospheric OH Magnetic fields appear ubituitous throughout the circumstellar envelopes (CSEs) of evolved asymptotic giant branch (AGB) stars. However, the magnetic field strength on the surface of AGB stars is very poorly constrained. It is the magnetic field near the surface that will possibly affect the stellar mass loss and hence evolution. So far only one AGB star has had its surface magnetic field measured using observations in the visible and very few other AGB stars are accessible with this technique. Maser observations have revealed strong magnetic fields in the CSEs, but it is unclear if these measurements can be extrapolated to the star. Recently, ALMA discovered non-masing excited OH in the atmosphere of AGB stars. The magnetic succeptibility of OH means that there is now a direct probe of the magnetic field near the stellar surface. Here we propose to detect the magnetic field of the AGB star W Hya for which maser observations imply a field of several Gauss near the surface. If we can confirm this field we can, for the first time, benchmark the maser measurements in the CSEs with the surface field and determine if the magnetic field has the power to affect the mass loss mechanism. Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure Stars and stellar evolution 2023-08-04T19:29:58.000
6 2018.1.00503.S 119 The galaxy-wide impact of powerful feedback in ULIRGs In recent years, the SPIRE Fourier Transform Spectrometer (FTS) has enabled observations of high-J CO transitions (J = 5 to J = 13) for a large number of local Ultra Luminous infrared galaxies (ULIRGs). These observations have been successfully used, together with low-J CO, mid-IR and far-IR spectral lines, in radiative transfer modeling codes (such as RADEX) to determine the relative contributions of Active Galactic Nuclei (AGN), star formation, and mechanical heating to the energy budget, and to constrain the density, temperature and column density in different phases of the interstellar medium (ISM). While such studies abound for local ULIRGs, they include only 3 sources hosting strong molecular outflows, a key step in quenching star formation in the outflow host galaxy. Here, we propose to observe low-J CO lines from 9 local ULIRGs hosting powerful molecular outflows, which have near-complete observations of the mid/high-J CO lines, as well as mid-IR and FIR spectroscopy, in order to complete their CO SLED from J = 1-0 to J = 13 - 12. This will be the first statistical test for any galaxy-wide changes to the ISM and star formation in ULIRGs as a result of molecular outflows. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2019-10-25T20:11:13.000
7 2022.1.01178.S 0 The ISM distribution, gas kinematics and system dynamics of five rotation-dominated quasar-starburst systems at z > 6 We propose ALMA band-6 observations of the [CII] line along with the dust continuum emission toward five z > 6 quasar-starburst systems at resolutions of 0.042" to 0.09" (physical sizes of 250 to 500 pc at the quasar redshifts). We reduced ALMA archival [CII] data of ~100 z~6 quasars, and selected five objects that are [CII]-brightest and rotation-dominated quasar-starburst systems. With the proposed high resolution ALMA [CII] observations combined with archival short-baseline [CII] data, we will study the spacial distribution and the extent of the ISM, the resolved [C II]-FIR deficit, and the heating mechanism of the dust. With 3D tilted ring kinematic modeling, we will study the gas kinematics in the sub-kpc to kpc regions, and search for evidence of non-circular motions. Through dynamical modeling, we are able to investigate the composition and the distribution of mass matters in these quasar-host systems. Especially, we will have the dynamical measurements of the black hole masses in the earliest Universe for the first time. In addition, we will investigate the coevolution of quasars and their hosts across cosmic time. High-z Active Galactic Nuclei (AGN) Active galaxies 2024-11-14T18:53:32.000
8 2022.1.01587.S 0 ALMA reveals a [CII] radio-driven kpc-scale outflow at z~6 The interactions between radio jets and the interstellar medium are thought to play a defining role for the co-evolution of supermassive black holes and galactic stellar masses. However, observational constraints on these feedback processes are still very limited at z~2 and non-existent beyond z>4, where theoretical galaxy formation models can be best constrained. Recent ALMA observations have revealed evidence of a collimated [CII] emission, with similar morphology, extent, and position angle to a ~2kpc jet in a radio-bright quasar at z~6. This is the first evidence of a [CII] outflow driven by a radio jet at these redshifts. However, the limited significance (2-4sigma) of the emission prevents a detailed analysis of this unique system. Here we propose deep 0.04" (~300pc) resolution that will allow us to test directly how the radio jet is affecting the dust and gas in the host galaxy. We will quantify for the first time the effects of radio jets during the formation of a massive galaxy within the first billion years of the universe. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 2024-08-18T17:47:26.000
9 2016.1.01253.S 42 Origin and evolution of atomic gas in debris discs - A new way of studying planetary systems Thanks to ALMA, CO has been detected around a few main sequence stars with infrared excess. This comes as a surprise as debris discs were expected to be gas free. In most of these systems, CO is thought to be secondary gas produced from the solid bodies of debris belts. CO is then quickly photodissociated by impinging UV radiation and transforms to C+O that viscously evolves spreading all the way into the star. Kral et al. (2016) created the first self-consistent model of the evolution of such atomic gas in debris discs and can explain all gas observations of Beta Pic. The model now needs to be tested for other systems with different spectral types, CO production rates, ... To do so, we need to observe C I in other systems and we have chosen the best two targets to realise this test. These observations will definitely tell us whether the mystery of the origin and evolution of gas is now solved. C I observations would not only confirm our scenario but is also a new avenue to extend our knowledge of inner regions of planetary systems where terrestrial planets are located... Debris disks Disks and planet formation 2018-04-21T17:03:48.000
10 2021.1.00055.S 76 Comprehensive ISM view down to a ~100 pc scale for a sub-L* galaxy at z=6 by ALMA, JWST, and JVLA We propose deep follow-up for [CII]158um and [OI]146um lines targeting two multiple images of a strongly lensed galaxy at z=6 discovered by a 100-hr ALMA Lensing Cluster Survey. Among normal star-forming galaxies at z>6, both images are the brightest lensed sources known, (H~23.7mag, [CII] flux~20mJy), but intrinsically a faint z=6 sub-L* galaxy (Mstar~10^9Msun) due to high magnifications of mu~20-160. Combined with scheduled deep JWST and JVLA observations that precisely characterize host ISM and molecular gas properties, we will assess the cold ISM properties down to a ~ 100 pc (source plane) via the two major coolant lines with underlying dust continuum, dramatically transforming our understanding of a typical z=6 galaxy by 1) studying detailed [CII] kinematics including star-forming clump motions and rotation curve of the host up to ~3 x effective radius, 2) searching for [CII] broad-wing and extended halo features, and 3) mapping every phase of the ISM: ionized, diffuse, dense neutral, and molecular. We will also observe the [CII] line of the two other multiple images to 4) refine the lens models. A comparable study is impossible, except for this uniquely lensed system. Lyman Break Galaxies (LBG), Gravitational lenses Galaxy evolution 2023-02-02T10:53:02.000
11 2022.1.00435.S 20 A deep search for H2DO+, the missing link in the gas-phase deuteration chemistry of water The deuterium-to-hydrogen (D/H) ratio is the main tool for investigating when, where, and how the water on Earth, in comets, and other solar system bodies formed. Therefore, a thorough understanding of the water chemistry network in star-forming regions, and the deuteration routes in particular, is key for interpreting the observed D/H ratios. A cornerstone molecule in the gas-phase water chemistry is H3O+. Observations of its deuterated isotopologue, H2DO+, and hence H2DO+/H3O+ measurements, were not possible in the pre-ALMA era because of the lack of sensitivity at high frequencies. We aim at measuring the H2DO+/H3O+ ratio around a protostar for the first time. A deep search for H2DO+, along with observations of H3O+ to constrain the spatial extent and excitation, is proposed in the high-mass star-forming region G34.26+0.15, where H3O+ emission was previously detected with a single-dish telescope. The proposed observations will pin down the importance of the low-temperature gas-phase channel in the deuteration of water and contribute to a more complete picture of the water deuteration chemistry. High-mass star formation, Astrochemistry ISM and star formation 3000-01-01T00:00:00.000
12 2021.1.01415.S 0 Tracing evolution of giant molecular clouds in the Large Magellanic Cloud: CI view The aim of this observation is to reveal for the first time the detailed molecular gas distribution of an active star-forming region within a low-metallicity environment to understand the formation and structure of GMCs as well as the star-formation process at low metallicity. We propose mosaic observations toward five GMCs having different evolutionary stages in the LMC in [CI] with a final angular resolution of 3 arcsec by using the ACA standalone mode. CO observations in previous cycles will be used to precisely determine the density and temperature of the CO gas, and in combination with the velocity information, we can investigate the dynamics of GMCs associated and cold-dense molecular clumps prior to massive star formation. [CI] line is an important probe to reveal the distribution of molecular gas without CO emission, being a significant mass component of the cloud in low metallicity environment, affecting the system's self-gravity and providing an additional supply of gas to fuel star formation, and also a key to understand the variations of the CO-to-H2 conversion factor. Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds ISM and star formation 2023-09-16T09:36:29.000
13 2013.1.00883.S 3 HD141569: Pristine gas and evolved dust The transition from proto-planetary to debris disk is a crucial stage of disk evolution and planet formation scenarios. It is a fast process, very few sources have been identified with simultaneous signatures of primordial and 2nd-generation material. Among them, HD141569 is a B9.5Ve star surrounded by several rings of micronic grains imaged at optical and NIR wavelengths (R>200 AU). The dust disk presents asymetries and tightly wound spirals which are likely resulting from planet formation. The 12CO(2-1) image from the IRAM array reveals that the CO disk is pristine and distributed in a cold (20K at 100AU), geometrically thin, but reasonnably optically thick disk, extending out to 225AU. We propose to use the unique sensitivity and resolving power of ALMA to study the gas and dust properties using B3 (continuum observations at 0.8'' resolution) and B7 (continuum, 12CO and 13CO 3-2 at 0.4'' resolution). The proposed observations will provide for the first time a quantitative measurement of the degree of evolution of the gas and dust in a transient object wich evolution status is critical with respect to the formation of gaseous planet. Debris disks Disks and planet formation 2016-11-09T23:12:18.000
14 2017.1.00090.S 33 Do the Accretion Environments of Low Luminosity AGN Resemble that of Sgr A*? Low luminosity active galactic nuclei (LLAGN) are powerful probes for understanding accretion and outflow in black hole systems. They represent an important link to the lowest luminosity AGN, Sagittarius A*, with 9 orders of magnitude sub-Eddington luminosity. Millimeter wavelength polarimetry has proven a unique tool for characterizing the accretion environments of Sgr A* and other LLAGN, including M87 and 3C 84. We propose ALMA Band 6 polarimetry to measure the accretion rates in three nearby LLAGN: NGC 4374 (M84), 4552, and 4579. All sources are currently undetected in linear polarization up to a frequency of 43 GHz (and 230 GHz in the case of NGC 4374). The theory of radiatively inefficient accretion flows predicts rotation measures (RMs) between 10^4 and 10^10 rad m^-2 for these sources; these RMs would depolarize past VLA measurements. ALMA polarimetry will provide sensitivity to RMs as large as 3 x 10^9 rad m^-2, testing accretion models on scales between 10 and 100,000 Schwarzschild radii. Detection of the RM will provide an accurate constraint on the accretion rate for direct comparison with X-ray estimates. Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei Active galaxies 2019-04-27T18:30:22.000
15 2017.1.00078.S 170 Can C0/CO abundance ratio be a robust discriminator of PDRs and XDRs? -A test study in NGC 7469 To identify energy sources of galaxies at mm/submm (least affected by dust extinction) can be an excellent way to uncover dust-obscured AGNs, which are elusive at optical. Although we have proposed that HCN abundance enhancement with respect to HCO+ can be a potential method, we here propose to test another energy diagnostics using C0 and CO lines to make an independent way to pursue. Indeed, chemical models predict a drastic (orders of magnitude!) enhancement of [CI](1-0)/13CO(2-1) ratio in XDRs than in PDRs, which reflects much higher C0/CO abundance ratio in the former. In this program, we then try to measure (i) [CI](1-0)/13CO(2-1) flux ratio, and (ii) C0/CO abundance ratio via non-LTE modellings (using 12CO J=1-0, 2-1, 3-2, and [CI](1-0) lines), in the central 2 kpc of the type-1 luminous Seyfert galaxy NGC 7469. We will selectively probe its (relatively large) XDR with a proposed 0.3" resolution. This is the first, robust and spatially resolved measurement of the C0/CO ratio around an AGN. As an additional goal, we also try to estimate a molecular mass conversion factor from [CI](1-0) line, as this is argued to be a good mass tracer applicable to high redshifts. Active Galactic Nuclei (AGN)/Quasars (QSO), Galaxy chemistry Active galaxies 2019-10-15T23:36:19.000
16 2013.1.01194.S 55 A CF+ survey of the diffuse medium in the inner galaxy Herschel and Planck data confirm the presence of diffuse ISM gas that is not well traced by the usual atomic or molecular probes, ie H I or CO. It can be followed in C+, in emission at 1.9 THz, but we propose a more accessible probe of C+ by following gas-phase fluorine into HF and CF+. When H2 is present, fluorine concentrates into HF exothermically via F+H2->HF+H and forms CF+ via C+ + HF->CF+ + H, making CF+ the 2nd largest fluorine reservoir where C+ and H2 coexist. Since HF tracks H2, CF+ is a perfect tracer of the H I-> H2 transition. Recent observations toward the Horsehead and the bright QSOs BLLAC and 3C111 illustrate this in the science case. We propose to use ALMA to perform an exploratory survey of CF+ absorption in the inner galactic plane using well characterized sight-lines towards continuum sources studied in the Herschel PRISMAS survey and other means. We target HOC+ simultaneously because HOC+ forms in the reaction of C+ and H2O. By comparison with the existing data, we will determine the fraction of diffuse gas in molecular form and investigate the relative contributions of atomic, molecular and ionized gas to the C+ budget. Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) ISM and star formation 2016-12-22T12:37:49.000
17 2013.1.01099.S 9 First interstellar detection of the H2F+ ion and fluorine chemistry in the z=0.89 molecular absorber toward PKS1830-211 By using new laboratory transition frequencies of the H2F+ ion, we propose a search for the ion and observations of HF and CF+ in the z=0.89 molecular absorber toward PKS 1830-211. The detection will contribute to understanding the fluorine chemistry through determined abundances of fluorine bearing molecules. So far H2F+ has not been detected in space. From chemical reaction, the ion is expected to be abundant in diffuse cloud. The molecular fractional abundances of PKS 1830-211 are found in-between those in typical Galactic diffuse and translucent clouds. The condition is suitable for H2F+ production. The rotational temperature of strongly polar molecules is equal to Tcmb=5.14 K at z=0.89, so the absorption spectrum is not too crowded (only low-energy levels are populated), and line identification is easy. HF and CF+ are known to be abundant reservoir of fluorine, and the observations are important for understanding chemical reactions in low temperature cloud. Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2016-07-20T00:00:00.000
18 2019.1.01797.V 0 Imaging of the black hole shadow and jet base in M87 The supermassive black hole (SMBH) at the heart of the Virgo A galaxy (M87) powers one of the most well-studied relativistic jets in the sky. Due to its high mass and close proximity, it shows the shadow cast by the black hole (BH) event horizon (EH), and promises successful imaging with unprecedented detail the jet launching mechanism. We propose four tracks of Band 6 VLBI observations with the EHT+ALMA VLBI array. The successful observations in Cycle 4 and the improvements introduced for Cycle 7 (inclusion of the KP and the NOEMA, together with a further optimized GLT) provide enhanced angular resolution and sensitivity to refine the shadow feature and enable new tests of strong-field GR. The relativistic jet and BH magnetosphere can be mapped including polarimetry, testing models of jet launch from spinning BH at the EH. The observations will be accompanied by complementary (requested) 3mm observations with the GMVA+ALMA, together with a multi-band campaign including X and gamma rays up to the TeV regime. Ultimately, we aim to connect the smallest objects predicted by Einstein's GR to galactic scale outflows that impact large scale structure in the Universe. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2024-12-19T23:36:13.000
19 2021.1.01719.S 40 Unveiling the thermodynamical properties of distant, massive ICM-selected clusters We propose ACA and ALMA observations of the Sunyaev Zeldovich (SZ) effect of two clusters, one dynamically disturbed, one relaxed, in the most massive and distant sample of SZ-selected clusters identified by the South Pole Telescope 2500 deg2 survey. We will exploit the exquisite synergies provided by ALMA, ACA, and SPT observation to probe the SZ signal of the two high-z clusters from kpc scales out to the virial radius. In combination with existing deep HST, Spitzer, XMM-Newton, and Chandra data, this will allow for building a comprehensive picture of the physical processes shaping the properties of high-redshift clusters. This will represent a key pilot study for demonstrating the feasibility of a detailed characterization of those transformational processes that have a dramatic impact on the early evolution of clusters and cluster galaxies. Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters Cosmology 2023-02-04T11:15:35.000
20 2015.1.01471.S 8 Isotopic ratios in Neptune's atmosphere and the origin of CO and HCN (Resubmission of cycle 1 program) This proposal is a resubmission of the proposal 2012.1.00624.S accepted in cycle 1 with "highest priority of being observed", but this project has not been observed. In order to avoid duplication, if this project is finally observed in cycle 2, we do not need observations during cycle 3. Isotopic measurements represent a powerful tool to diagnose the origin and evolution of planetary atmospheres. The 14N/15N ratio, in particular, shows a large range of variability throughout the Solar System. The main goals of this proposal are i) to determine the 12C/13C, 16O/18O and 14N/15N isotopic ratios in Neptune CO and HCN, in order to constrain the origin of these species in Neptune's atmosphere and to characterize isotope-related fractionation effects within the atmosphere ii) to take benefit of the large bandwidth of ALMA to simultaneously search for two additional species, CS and CH3CCH. The detection of CS would bring support to the cometary origin hypothesis for CO and/or HCN, and the measurement of CH3CCH would provide new constraints on Neptune's hydrocarbon photochemistry. This will provide novel clues to understand the origin of these molecules. Solar system - Planetary atmospheres Solar system 2017-05-11T21:23:28.000
21 2016.2.00172.S 9 Unveiling the merging substructures of a high-z cluster mapping their Sunyaev-Zel'dovich effect ClJ0152-1357 is a massive z=0.834 non-virialized galaxy cluster characterized by a complex combination of several merging subclumps observed in many spectral bands. Thanks to its high redshift, high mass, electron temperature and density, and the merging directions apparently lying on the plane of the sky, it is a representative target to investigate the interacting substructures in a cluster in the early stages of its evolution. Our 18 GHz ATCA observations (Massardi et al. 2010), limited to the region of the most massive subclump, showed that the peak of the Sunyaev-Zel'dovich (SZ) signal is significantly displaced from the X-ray peak possibly as a consequence of major mergings of the subclumps. The combination of X-ray and SZ mapping at comparable resolutions can disentangle the temperature and the density distributions and retrieve a detailed picture of the ISM. Henceforth, we propose Band 4 (at the maximum of the negative SZ peak) ACA standalone observations to map to ~10 arcsec resolution (comparable to that of the available XMM-Newton images) the whole cluster region, to unveil the subclump properties and reconstruct models of the substructure interactions. Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters Cosmology 2019-07-08T00:00:00.000
22 2018.1.01142.S 120 Exploring the molecular gas and continuum emission in giant gravitational arcs Giant gravitational arcs offer the best opportunity to obtain sub-kpc observations of the interstellar medium in high redshift galaxies. The first targets were intrinsically infrared luminous lensed galaxies, observations that reveal the conditions of the bright end of dusty star-forming galaxies. Here we aim to study the ISM of optically bright strongly lensed galaxies. We propose observations of mid-J CO lines and continuum observations in three highly magnified (>30) low-metallicity star-forming galaxies. We will obtain gas and dust masses, as well as obscured star-formation rates, in three of the brightest and most studied optical arcs. The availability of good lensing models will allow translating our detections into source plane properties, one of the main issues associated with the observations of lensed galaxies. High magnification values are usually associated with large angular extents in the image plane. In these cases, the lower resolving power of ACA offers the optimal observation setup for the detection of the emission of the arcs. The results from this campaign will be crucial for future higher spatial resolutions observations with ALMA. Lyman Break Galaxies (LBG), Gravitational lenses Galaxy evolution 2020-09-10T16:31:15.000
23 2017.1.00864.T 53 Constraining Jet Formation and Evolution with X-ray Binaries Relativistic jets are launched from accreting black holes (BHs) on all scales, from stellar-mass BHs in X-ray binaries (BHXBs) to supermassive BHs in active galactic nuclei (AGN). These jets deposit significant amounts of energy into the surrounding medium, which affects star formation, galaxy evolution, and even the distribution of matter in the universe. Therefore, it is essential that we understand the physics of these accretion-fed outflows. Of the many objects that launch jets, BHXBs are ideal testbeds, as they evolve on timescales of days to months (unlike AGN that evolve over millions of years). Broad-band spectral measurements of BHXB jet emission constrain the physical conditions in the jet, which can then be coupled to the properties of the accretion flow, probing the mechanism that governs how jets are launched and quenched. The mm regime bridges a crucial gap between radio and IR frequencies in the broad-band jet spectrum. Here we target the next outbursting BHXB with ALMA, to probe the evolving mm flux. Coupled with our exceptional multi-wavelength coverage, we will constrain the dynamic broad-band spectral energy distribution in BHXBs with unparalleled accuracy. Black holes, Transients Stars and stellar evolution 2018-10-31T01:19:57.000
24 2017.1.00127.S 22 Extended Star Formation in the Brightest Unlensed Submillimeter Galaxies Distant SMGs represent the most massive of the young galaxies rapidly building up their mass in the early universe. Their importance in terms of understanding the cosmic stellar mass build-up history is amplified if they represent the pinnacle of the "cosmic downsizing" phenomenon. We have obtained 345GHz continuum images at 0.02" resolution toward three unlensed submillimeter galaxies during cycle 3 of ALMA, with a primary science goal to investigate the detailed spatial distributions of dust in the intrinsically most luminous SMGs as a direct test of how such extreme starbursts can be fueled and sustained. We found that the morphology of dust in the central kpc is highly complex with extreme star formation properties that are comparable to (or exceeding) the Eddington limit for starbursts. We have also found that the amount of missing flux is extremely high (70-85%) compared to lower resolution SMA images, which suggests that the bulk of the star formation is in fact taking place in the extended disk. Here we propose 2.3 hours of Cycle 5 time in the C43-5 configuration to recover this missing flux and to properly image the dusty star formation activity beyond the central kpc. Sub-mm Galaxies (SMG) Galaxy evolution 2019-01-30T02:04:10.000
25 2019.A.00017.S 10 ALMA Observation of the New Record Breaking Quasar We request ALMA DDT observations of a newly discovered redshift record breaking quasar, J0313-1806, at z=7.61. These observations would challenge models of the early growth of supermassive black holes (SMBHs) and place new constraints on the co-evolution between SMBH and its host at cosmic dawn. In particular, the proposed observations will deliver a 100 times better redshift measurement, and enable us to direct probe the morphology and kinematics of the quasar host galaxy. In addintion, the ALMA observations will allow us to investigate the spatial distribution of dust emission and star formation in the quasar host galaxy. These measurements will be combined with the relativistic quasar outflows detected in our infrared spectrum, and allow us to probe the mode of star formation, its connection to SMBH growth and AGN feedback. The ALMA observations will also be used to search for [CII] emitters in the vicinity of the quasar and probe whether this early quasar reside in an overdense region. Moreover, the host galaxy properties measured from ALMA observations will be crucial for planning the JWST Cycle 1 and ALMA Cycle 8 programs for further detailed studies of this exciting object. High-z Active Galactic Nuclei (AGN) Active galaxies 2021-10-09T19:20:34.000
26 2022.1.00624.T 0 Unveiling Short GRB Millimeter Afterglows with ALMA Short gamma-ray bursts (SGRBs) are relativistic explosions which originate from the mergers of two compact objects (NS-NS/NS-BH). Such merging systems are also at the forefront of transient astrophysics, with the recent multi-messenger discovery of GW170817. Modeling of SGRB afterglow emission from the radio to X-ray bands provides a unique way to probe the burst basic explosion properties: the energy scales, circumburst densities, and jet opening angles. These properties not only provide critical insight into merger environments, but also serve as a vital baseline for comparison to properties inferred from future gravitational wave events. In the millimeter band, the faint and rapidly-fading afterglows of SGRBs require the sensitivity and dynamic scheduling of ALMA. Here, we propose to use ALMA TOO observations to identify and monitor, or place deep limits on the millimeter afterglows of 2 SGRBs in Cycle 9. Our proposed observations will be sensitive to SGRBs over a wide range of densities and jet opening angles. Our search will continue ALMA's newfound role in SGRB millimeter studies, and will offer hundred-fold improvement over previous millimeter searches with other facilities. Pulsars and neutron stars, Transients Stars and stellar evolution 2024-11-23T04:01:15.000
27 2023.1.00334.S 0 Measuring accurate gas masses for the exoALMA planet-forming disks The gas mass of planet-forming disks is a crucial ingredient for our understanding of planet formation. We propose to measure accurate gas masses for the 15 sources in the ALMA large program exoALMA, ALMA's first exoplanet hunting campaign, by observing N2H+ 3-2 in the 11 sources where this line has not yet been observed. Measuring gas masses is difficult, with the most readily available gas mass tracer, CO, having been shown to have up to two orders of magnitude uncertainty due to a lack of constraints on the CO abundance. N2H+, a chemical tracer sensitive to the CO abundance, was recently shown to observationally measure the CO-to-H2 ratio and gas disk mass when combined with CO isotopologue lines, providing a path to measuring accurate gas masses. We will combine the requested observations with archival N2H+ and CO observations to measure gas masses and CO-to-H2 ratio for the 15 exoALMA disks, the sample of disks most thoroughly searched for exoplanets with ALMA and with the best characterization of these planets. Linking these two, the gas reservoir and the young planets that are actively forming in it, will provide a massive leap in our understanding of planet formation. Disks around low-mass stars Disks and planet formation 2025-06-11T00:32:35.000
28 2017.1.00815.S 40 A Wide, Deep Dense Gas Map of M100 to Connect Extragalactic and Galactic Dense Gas Results Resolved observations of nearby galaxies and the Milky Way's Central Molecular Zone suggest an environment-dependent role for dense gas in star formation. These results conflict with current work on the Solar Neighborhood, which finds a uniform dense gas star formation efficiency. To help resolve this tension, we propose to make the first resolved observation of emission from spectroscopic ``dense gas tracers'' (HCN, HCO+, CS) that spans from the center of a galaxy all the way out to conditions similar to those found in the Solar Neighborhood. This will test the theoretical idea of a threshold ISM pressure above which clouds couple to their environment. And it will link the two major bodies of work on dense gas: extragalactic and Milky Way. We target NGC 4321 (M100), a very well studied nearby galaxy with dynamical features similar to the Milky Way. We have already studied the inner part of the galaxy and shown that the key trends exist. We are now in a position to make the first full galaxy, resolved dense gas map. Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2020-09-27T15:40:01.000
29 2019.2.00033.S 20 Atomic carbon in a prototypical barred-spiral galaxy M83 Atomic carbon (CI) has been proposed as a tracer of molecular mass alternative to CO, especially in high-redshift galaxies where cosmic-ray induced reactions can destroy CO, or in outflows where the optical depth of CO is unknown. However, the CI abundance with respect to H2 varies with many other factors such as turbulence, cloud age, UV field, and density. We first need to understand how the CI abundance changes in a nearby galaxy where the physical conditions are well known. We propose to map the closest and brightest face-on barred-spiral galaxy M83 in CI over 5.2kpc x 5.7 kpc covering various galactic structures such as the galactic center, bar, arm, and interarm. We will examine the variation of the ratio between two major forms of carbon, CI and CO, among these galactic structures and examine the influence of turbulence, cosmic rays, and UV radiation. We already have larger and deep ALMA maps of CO 1-0 and 2-1. We will also compare the chemical state from CI/CO with the excitation inferred from CO(2-1)/(1-0). Our detailed analysis in M83 will serve as the best reference for CI studies in galaxies under the wide variety of physical conditions we cover. Starbursts, star formation Active galaxies 2022-08-17T11:54:05.000
30 2016.1.00464.S 29 Determining the chemical origin of gas-phase methanol in the TW Hya protoplanetary disk Detecting complex organic molecules (COMs) in protoplanetary disks is a "holy grail" for astrochemistry, because it links the complexity observed towards protostars with that in comets. The ALMA era has shone light on COMs in disks with the first detections of gas-phase methyl cyanide, CH3CN, in MWC 480, and methanol, CH3OH, in TW Hya. As a COM with an ice-chemistry origin, CH3OH is a powerful probe of the location and abundance of the disk ice reservoir, and of the non-thermal desorption mechanisms required to release it from the grain surfaces. We will observe four transitions of gas-phase methanol which span a range of upper level energies (17-40K), with a spatial resolution of 0.5" (25AU) and a high sensitivity (< 2mJy/beam) to constrain its radial and vertical location in TW Hya. Parametric modelling to reproduce the spatially and spectrally resolved line emission will reveal its location and abundance, and chemical models will determine if theorised processes (e.g. photodesorption) are responsible for its chemical origin. These data are critical for robust determinations of the likelihood of using ALMA to detect COMs of even higher complexity in solar-analogue disks. Astrochemistry ISM and star formation 2018-04-26T09:44:43.000
31 2021.1.01722.S 18 Revealing the Formation of Cold Supernova Ejecta Dust at the Center of SNR 0540-69.3 Core-collapse supernovae (SNe) are thought to be the main source of dust in the early universe; however, the mechanism of SN dust formation is poorly understood. SNR 0540-69.3 is the youngest plerionic supernova remnant (SNR) in the Large Magellanic Cloud, and it is called a twin of the Crab due to its pulsar wind nebula (PWN). Spitzer and Herschel fluxes indicate the presence of dust at the center of this SNR, but their angular resolutions are insufficient to resolve the dust clumps. The archival ALMA Band 3 image shows detailed structures of this PWN, including bright clumps around the pulsar, and extended filaments apparently aligned along a CSM, but dust emission is too weak at this frequency. To reveal the distribution of cold dust in SNR 0540-69.3, we request ALMA Band 6, 8, and 10 observations. We plan to use the Band 6 and the archival Band 3 images to construct a map of synchrotron spectral indices, and then use it for background subtraction to reveal dust emission in Band 8 and 10 images. We expect to resolve the clumps and filaments of cold SN ejecta dust, and obtain a unique sight to understand the roles of PWNe and circumstellar media on SN dust production. Supernovae (SN) ejecta Stars and stellar evolution 2023-08-09T03:27:38.000
32 2016.1.01123.S 176 Formation and early evolution of embedded proto-clusters Contrary to the classical paradigm for cluster formation, recent numerical and observational results suggest that both stars and gas are independently virialized during the early stages of cluster evolution. Combining the spatial resolution and large-scale mapping capabilities of the ALMA ACA + TP arrays as stand alone interferometer, here we propose to investigate the internal structure of a selected subsample of 6 intermediate-mass clusters in the Orion A cloud. Using different ALMA Band 3 millimeter line tracers for both the dense and diffuse gas components, we expect to systematically characterize impact of the mass inflow and stellar feedback on the evolution of these proto-clusters. In addition to previous VISTA, Spitzer, Herschel-Planck, and APOGEE results in these regions, we aim to statistically test the most recent theoretical predictions of our simulations for embedded clusters comparing the dynamical state of both stellar and gas components in these young stellar systems. Intermediate-mass star formation ISM and star formation 2019-11-11T00:00:00.000
33 2021.1.00225.S 298 Mapping Obscuration to Reionization: A blank field 2mm survey in COSMOS We propose 36 hours of band 4 (2mm) time to extend the Mapping Obscuration to Reionization (MORA) Survey to a 0.2deg^2 region in COSMOS to 90uJy/beam RMS (`Ex-MORA') with these goals: (1) Detect ~20 new z>4 dusty star-forming galaxies (DSFGs) to directly constrain the galaxy infrared luminosity function (IRLF) beyond z>4 and ~double the number of known unlensed DSFGs at z>4. Though some DSFGs are known out to z~7, their volume density is unconstrained and requires an unbiased census which gives volume density constraints. (2) Measure the average ISM masses of Epoch of Reionization (EoR) galaxies and the cosmic molecular gas budget through 2mm stacking to z~8 with a sensitivity of ~10^9Msun. Ex-MORA will be covered by deep JWST imaging (from COSMOS-Webb and PRIMER) leading to the detection of thousands of new EoR galaxies in the Ex-MORA footprint. Mapping at 2mm rather than ~1mm provides significant advantage for the z>3 Universe as the negative K-correction filters out dusty galaxies at lower redshifts. The rich set of ancillary data in the center of COSMOS will give detailed constraints on detections, allowing direct refinement of the IRLF close to and embedded within the EoR. Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) Galaxy evolution 2023-05-24T22:16:52.000
34 2015.1.01543.T 20 Unlensed HyLIRG systems from the South Pole Telescope 2500deg^2 survey From a 2500 degree^2 survey, the South Pole Telescope (SPT) has detected at 1.4mm, ~100 bright high redshift star forming galaxies, with APEX/LABOCA and Herschel/SPIRE followup. Most of these are strongly lensed ULIRGs, however a few are candidates for unlensed, hyperluminous galaxies. We propose to map the extreme z=4.30 Hyper-luminous galaxy system, SPT2349-56 using Band-3 CO(4-3) Band-4 CO(7-6) & [CI], and Band-7 [CII]. SPT2349-56 is completely unlensed, and is the current record holder for the most luminous system (in a 20" beam) in the Universe. Our observations will characterize this systems, going well beyond the ALMA subcomponents already detected in a Band-7 mapping program. Our main scientific goals are (1) detect all subcomponents in continuum and lines which make up the S870=60mJy from single dish measurements; (2) confirm the likely nature of this sytems as group/clusters caught in the act of forming massive galaxies; (3) detect continuum and CO lines from additional faint S850~1-2mJy sources identified in the Band-7 imaging (and beyond), completely characterizing this system in dust and molecular gas. Sub-mm Galaxies (SMG), Galaxy Clusters Galaxy evolution 2018-03-14T22:34:41.000
35 2016.2.00046.S 334 WISDOM: From (Giant) Molecular Clouds to Supermassive Black Holes Supermassive black holes (SMBHs) are key to understand galaxy evolution, but the SMBH mass-central velocity dispersion relation underpinning our understanding is based on a relatively small number of measurements and a handful of methods. We have shown that it is straightforward to estimate the mass of SMBHs in the ALMA era, by probing the near-Keplerian rotation of molecular disks around them at high angular resolution. As part of mm-Wave Interferometric Survey of Dark Object Masses (WISDOM), we have identified numerous promising targets from high resolution (0.1") dust imaging with HST, and hereby request low spatial resolution (5.4") CO(2-1) imaging of 21 galaxies across the Hubble sequence. We aim to 1) quantify their molecular gas content, thus identifying the best targets for SMBH measurements at higher resolution, and 2) study the properties of the spatially-resolved molecular cloud populations analogously to the local universe, where constraining the diffuse emission is essential. Our work will revolutionise studies of the co-evolution of SMBHs and galaxies, and systematically probe molecular cloud properties in the central bulge-dominated regions of many galaxies. Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties Active galaxies 2018-09-08T00:00:00.000
36 2018.1.01055.L 690 The Chemistry of Planet Formation Planets form and obtain their compositions in dust and gas-rich disks around young stars. The planet forming process is intimately linked to the disk chemical structure. First, chemistry shapes the outcome of planet formation, including planetary hospitality to life. Second, the chemistry is sensitive to the distribution of dust and pebbles in disks, and as planets open up disk gaps they may change the chemical environment within which they form. Third, molecular emission is often the only tool we have to explore disk ionization levels, kinematics and mass distribution, all key ingredients of planet formation models. We propose a Large Program to map out the radial and vertical disk chemical structures at 10 au scales, in five disks where dust sub-structure is detected and planet formation appears to be ongoing. The resulting data will give us access to the chemistry in the planet forming zone of disks, explore how ongoing planet formation shape the disk chemistry environment, and constrain the disk gas properties in the previously unexplored inner disk midplane. Disks around low-mass stars Disks and planet formation 2021-01-18T00:58:05.000
37 2017.A.00021.T 21 Radio Polarlimetry of GRB Afterglows We have been monitoring the extremely bright GRB171205A afterglow in mm/submm band using SMA and ALMA (both 7m and 12m arrays). With our approved Cycle 5 program (2017.1.00801.T), we have also successfully conducted the radio afterglow polarimetric observation for the first time. Our coordinated SMA monitoring at 230 GHz reveals that unexpected brightening of the afterglow around 20 days after the burst, which would revise the total explosion energy. We therefore request additional two epochs of follow-up observations in early to mid of January. Gamma Ray Bursts (GRB) Cosmology 2018-07-24T07:07:24.000
38 2016.1.00572.S 8 A first look at the quiet Sun with ALMA The chromosphere, even the quiet one, is still not fully understood. Observations at mm wavelengths provide a unique chromospheric diagnostic. We propose to carry out center-to-limb observations at two frequencies (Bands 3 and 6) and perform detailed tests of 3D models of the quiet chromosphere. Our observations will shed light on thethermal structure of the quiet chromosphere by comparing them with state-of-the-art radiative MHD simulations and simultaneous imaging and spectral observations in optical, UV, EUV, and X-rays. We will assess whether the models can reproduce the mm observations and in case of discrepancies we will investigate their origin and how the models could be adjusted. The comparison of observations and models will also help us clarify the role of spicules in the limb brightening. The Band 3 observations will also be appropriate for the study of weak transient activity. These events may have a bearing on the heating of the upper atmosphere. Their occurrence rate will be compared with that of similar events that will be detected by the instruments that we have arranged to be co-observing with ALMA. The Sun Sun 2018-08-22T00:00:00.000
39 2018.1.01081.S 160 M0.10-0.08: A Local Laboratory to Study Shocked Gas in Extreme Environments Shocked gas is often observed in the inner 400 pc of gas rich galactic nuclei. Our Galactic center provides a unique opportunity to study shocked gas in molecular clouds at sub-parsec scales. We propose to study a compact molecular cloud, M0.10-0.08, which has elevated emission in several 3 mm shock tracers (e.g., SiO, HCN) in single-dish observations (Mills & Battersby 2017). However, the source of the shocked emission is up for debate. M0.10-0.08 is located near two possible mechanisms for this shock activity: an interaction between an expanding bubble and a gas stream (Butterfield et al. 2018) or a gravitational tidal compression (Kruijssen et al. 2015). The low-resolution of the single-dish observations are unable to determine the morphological structure of the shocked gas. Our proposed ALMA observations will be able to determine the location and kinematics of the shocked emission and determine which mechanism is producing the shocked gas in this cloud. By understanding the mechanisms producing shocked gas in this cloud, we will be able to better understand observations of shocked gas in external galactic nuclei. Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2020-01-07T00:00:00.000
40 2018.1.01488.S 48 A 150-pc Precessing Molecular Jet in the S0 Galaxy NGC1377: Outburst from an Accreting SMBH II We propose high (0."05= 5 pc) resolution Band 6 and 9 and moderate (0. "2=20 pc) resolution Band 3 ALMA observations of the centre of the unusual S0 galaxy NGC1377. With ALMA we discovered a highly collimated, precessing molecular outflow in NGC1377. We have recently imaged the jet at 2 pc resolution, revealing an extremely collimated jet of turbulent gas. The jet signals an unexplored and transient phase in the feeding of a supermassive black hole (SMBH). By mapping in the CO6-5, SiO, CO, HNCO and HCN emission we will trace different physical conditions allowing us to probe separate components of the nucleus and jet. We aim to (1) determine the jet's driving mechanism and search for the elusive torus; (2) study evolution of the gas in the jet and search for signs of dense gas and star formation; (3) investigate if the precession is caused by a misaligned accretion flow. This evolutionary phase should be extremely short-lived, which can explain other features of NGC1377, including its extraordinarily weak radio emission (far below the FIR-radio correlation). NGC1377 presents a prime opportunity to study the interplay between SMBH growth and feedback in unprecedented detail. Outflows, jets, feedback Active galaxies 2020-12-18T15:02:06.000
41 2016.1.00544.S 60 The birth of the giants: Imaging spectacular mergers at the dawn of galaxy formation Through a low-resolution ALMA snapshot survey of [CII] emission in QSO host galaxies at z>6 (within 1 Gyr of the Big Bang), we have unexpectedly identified four QSOs that show gas-rich companions at close (projected) separations. The implications of detecting interactions/mergers of gas-rich galaxies at such high redshift are significant, as they have been invoked in the past to explain the existence of massive `red and dead' galaxies by z~2. This sample of galaxy companions in the very early universe is the first known of this kind. Higher resolution/sensitivity imaging in the [CII] line and the underlying dust continuum is needed to investigate the on-going gravitational interactions through mapping the morphology and the kinematics of the gas. At the same time, we will constrain the dynamical masses of the QSO hosts and the companions, and map their star formation activity. Given the extreme brightness of our sources, high-resolution (0.2", 1.5 kpc) imaging of the [CII] and dust emission can be easily attained with ALMA. This will allow us to directly zoom into the build-up of the most massive galaxies at the dawn of cosmic time for the first time. High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution Active galaxies 2018-07-21T06:48:22.000
42 2016.1.00441.S 63 Probing the chromospheric heating regions of the solar analogue alpha Centauri with ALMA Comparison of our ALMA Band 3, 4, 6, 7, 8 and 9 data for the nearby solar-typ alpha Cen with results from our semi-empirical non-LTE chromospher models suggests that the data are sensitive probes of the location of the base of the transition region toward the corona. This chromospheric temperature plateau constitutes a critical region, beyond which a dramatic increase of the temperature occurs, due to the dissibation of non-radiative energy, likely carried by acoustic and MHD waves. This scenario is similar to that inferred for the Sun and thus provides feed-back to the solar physics community, which during C4 will gain access to solar ALMA observations in Band 3. The ``quiet Sun/star'' models assume stationarity, whereas the heating processes are highly dynamic, implying variability over a wide range of the mode spectrum, in particular for the active K-star alpha Cen B. The present proposal seeks to address observationally the steadiness of these unique chromospheric ALMA SEDs of alpha Cen A and B. The Sun, Main sequence stars Sun 2018-04-07T19:04:07.000
43 2017.1.01387.S 133 Understanding the nature of the ULIRG population in massive clusters at z ~ 1-1.5 Mid/far-infrared and submillimeter surveys of z~1-1.5 clusters have found apparent over-densities of dust-obscured, but strongly star-forming galaxies within some cluster cores. We have completed a 870um survey of ten massive z~1-1.5 clusters with SCUBA-2 finding a wide range of activity within their cores. Using ALMA to map an over-density of four SCUBA-2 submm sources in the core of a z=1.46 cluster we resolved this emission into fourteen distinct 1mm continuum sources (each possessing ULIRG-like luminosities) and simultaneously confirmed five of these as cluster members from CO(5-4) emission. We propose to use ALMA to measure the dust continuum and search for CO(5-4) line emission for ULIRGs in the central 3 Mpc of two other active clusters from our survey: RX J0152 and XDCP J0044. Using this data to examine the dynamics, molecular gas mass, star formation efficiency, and dust to gas ratio of these cluster ULIRGs to compare them to similarly luminous systems in the field and test their connection to potential descendant populations of elliptical and S0 galaxies in clusters today. Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Galaxy evolution 2019-05-18T21:28:54.000
44 2015.1.00407.S 11 Fast outflows quenching star formation at high redshift According to theoretical models, quasar driven outflows at high redshift clean massive galaxies of their gas content and quench star formation. We have recently discovered powerful AGN-driven outflows by studying the velocity field of [OIII]5007 in three quasars at z~2.4. The spatial distribution of the starforming regions in their host galaxies is anticorrelated with the presence of fast outflows, providing the very first evidence of quasar feedback quenching star formation. However, this evidence is tentative as it is based only on rest-frame optical spectra. We propose to map CO(3-2) to trace the distribution of the cold molecular gas in the three quasars, the only ones known so far showing evidence of outflows quenching star formation. The CO(3-2) maps will be compared with our [OIII] maps with similar spatial resolution: the molecular gas should be absent in the outflow dominated region, while surviving in the rest of the galaxy. This would be the first direct confirmation of star formation quenching by quasar outflows. Our ALMA observations will then open the way for the physical characterization of quasar driven feedback in larger samples of objects. Starburst galaxies, High-z Active Galactic Nuclei (AGN) Active galaxies 2017-11-04T19:08:23.000
45 2023.1.01327.S 0 Propagation of cosmic rays in molecular clouds interacting with a supernova remnant Cosmic rays (CRs) are a major component of the Galaxy. Especially, since low-energy CRs lose their energy via ionization, they are believed to have a strong influence on the chemical evolution in molecular clouds and on star and planet formation. However, the influence of CRs has been discussed only hypothetically in theories because the propagation process of CRs in molecular clouds is highly unknown. A recent study noted that CR protons with E~0.01 MeV, ~10 MeV, ~GeV attribute to the ionization rate, Fe I Ka line, and Gamma-ray emission, and indicated that the relative spatial distributions among the the three observables are the key to reveal the propagation process. Actually, there are no samples where the three observables were measured in the same region. We focus on the southwestern edge of the supernova remnant W44, where both the Fe I Ka line and gamma-rays are detected. We propose DCO+ (J=2-1) and H13CO (J=1-0) observations at two positions in this region to measure the ionization rate and its spatial distribution. This observation will reveal the propagation of MeV CRs observationally for the first time. Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 3000-01-01T00:00:00.000
46 2022.1.01314.S 110 ACA CO 1-0 Maps to Match MeerKAT 21-cm Maps Stars form from molecular gas, while most of the gas in galaxies is atomic gas, making the transformation of HI to H2 and the phase balance of the ISM one of the key elements in understanding galaxies. The SKA pathfinder MeerKAT is now the premier telescope to map 21-cm emission from southern galaxies. We propose ACA-only CO 1-0 mapping of 10 galaxies that are currently obtaining ultra-deep, high quality 21-cm maps of MeerKAT's Large Survey Project MHONGOOSE. This will create a paired ALMA CO and MeerKAT 21-cm data set that we will use to make new measurements on a series of important, but recently neglected topics: comparing the kinematics and stability of the molecular and atomic phases, measuring how the star formation law depends on ISM phase, and testing and improving prescriptions to predict and explain the balance of atomic and molecular gas in galaxies. With this proposal, ALMA will have produced CO maps for half of these key MeerKAT targets, a major step towards building synergy between these two facilities. Spiral galaxies Local Universe 2024-02-22T16:23:48.000
47 2017.1.01457.S 25 Do Molecules Condense in the Wind of the Nearest Lyman Break Analog Galaxy? The intergalactic medium was enriched with metals early in the age of the universe. These metals originated in low mass galaxies and were dispersed by galactic winds. While the shallow potential wells of these galaxies made baryon retention difficult, winds are not only subject to gravitational forces: cooling and dissipation of their bulk kinetic energy strongly limits their ability to escape. Lines that probe molecular gas are crucial for understanding the evolution of winds because this gas is the ultimate dissipative reservoir of kinetic energy via slow molecular shocks. To understand the role molecular gas plays in dissipation, we proposal to observe [CI](1-0) in the nearest analog of Lyman break galaxies in the early universe, Haro 11. Focusing on regions were gas is rapidly cooling between the warm ionized medium and warm neutral medium, we will probe the cooling and dissipation rate in the cold neutral/molecular media. Comparing these rates to our vast multiwavelength data set and kinetic energy output of the starburst, we will constrain the fractional energy lost in the molecular gas and take another step in determining the fate of winds from galaxies. Starbursts, star formation, Outflows, jets, feedback Active galaxies 2019-06-06T13:23:50.000
48 2017.1.01419.S 170 Planet formation in sparse stellar groups A significant fraction of the stars are born in sparse stellar groups of 10-100 stars. While the unprecedented sensitivity of ALMA has allowed to study the gas and dust masses and surface density profiles of many disks in star forming regions containing > 100 members, little is known about disks in sparse stellar groups. Constraining their properties is important as environmental conditions have an impact on disk evolution, which in turn will affect planet formation. For example, if disks in sparse groups are very extended (as expected from simulations), they could be the precursors of giant planets at large orbital distances. Here we propose to resolve the continuum and gas components of 10 selected gas rich disks in Epsilon- and Eta- Cham, the only sparse stellar groups within 250 pc with mean ages below 10 Myr. Given the age, distance, accretion levels, and SEDs, our sample comprises the best targets to study in detail disks in sparse stellar regions. We will test if these disks are different than those in crowded regions. Disks around low-mass stars Disks and planet formation 2019-11-22T16:26:32.000
49 2016.A.00011.S 0 Resolving the Chemical and Physical Structure of the Disk Forming Zone in L1527 This is a resubmission of the Cycle 2 proposal (2013.1.00858.S), which was evaluated as ranked-A. However, this program has not been completed due to the faults of the alma staff. So, we request the DDT observations to complete the original science goal proposed for cycle 2. We aim to resolve the transition zone between the infalling rotating envelope and the inner disk in the low-mass Class 0 protostellar core L1527 at a high angular resolution. With our ALMA Cycle 0 observations, we recently discovered a drastic chemical change in the transition zone around the centrifugal barrier (100 AU in radius). Carbon-chain molecules and their geometrical isomers reside mainly in the infalling rotating envelope, while SO preferentially traces the transition zone. Such a phenomenon seems to be caused by the accretion shock in front of the centrifugal barrier. Detailed exploration of the shock structure at a high angular resolution is thus an important and urgent issue for understanding the disk formation. This observation will put a stringent constraint on chemical evolution from protostellar cores to protoplanetary disks. Low-mass star formation, Astrochemistry ISM and star formation 2018-03-28T18:01:28.000
50 2015.1.00122.S 17 Gas and dust in the most luminous Lyman-alpha emitter at the epoch of re-ionisation: PopIII? We have recently discovered, and spectroscopically confirmed, the most luminous Lyman-alpha (Lya) emitter ever found, located well into the era of re-ionization (CR7, z = 6.604, L(Lya)=10^43.9 erg/s; Sobral+2015, arXiv:1504.01734). Near-infrared spectroscopy reveals the presence of a strong HeII164nm emission line (6 sigma) with narrow FWHM (130 km/s, thus disfavouring AGN and WR stars) and absence of metal lines, suggesting the presence of PopIII (metal-free) stars. We can only fit the SED of CR7 with a 2-component model consisting of i) PopIII and ii) a chemically enriched population, with each contributing 80% and 20% of the total UV light, respectively. HST/WFC3 observations confirm that CR7 consists of different components (A, B, C), separated by ~5kpc. The brightest (A) dominates the UV and may be PopIII-dominated, while B+C are likely enriched. Our extraordinary interpretation (finding metal-free stars for the first time) requires the most stringent tests. We therefore propose to target CR7 with ALMA in the [CII] line and the adjacent dust continuum, to test if any sign of metal enrichment (Carbon and/or dust in the ISM) can be found in this object and, if so, where. Lyman Alpha Emitters/Blobs (LAE/LAB) Galaxy evolution 2017-12-30T20:43:18.000
51 2012.1.00797.S 0 Deciphering black hole feedback: molecular outflow in an obscured quasar We propose to complete our search for outflowing molecular gas in the obscured quasar SDSS J1356+1026, which was ranked as a top-priority project in cycle 0, but has not been observed.This nearby (z=0.123) luminous quasar is blowing a 20 kpc-scale bubble of ionized gas, and provides strong evidence that black holes can inject energy into their large-scale environments without the help of star formation or radio jets. The bulk of the outflow may well be in the molecular phase, and we will search for it with CO(1-0) and CO(3-2) observations with ALMA. With one hour of integration, we will probe the majority of the outflowing mass and reveal the physial conditions of the outflow. SDSS J1356+1026 provides a key to understanding the prevalence of black hole energy injection in the growth and evolution of galaxies. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 2015-04-17T13:13:49.000
52 2019.2.00014.S 0 Line ratio mapping: recovering the Total Power in the northern filaments of Centaurus A Centaurus A is a very well-studied nearby radio-galaxy surrounded by HI shells. The powerful radio-jet emitted by the central AGN seems to hit one of these shells, at ~15 kpc from the galaxy centre. This source is thus a perfect target to probe the phenomenon of jet-gas interaction. On top of atomic gas, we have found molecular gas and studied the ionised gas and UV emission associated to young stars at the position of the interaction, lying in elongated filaments. We now aim to study accurately the spatial variations of the cold gas physical conditions within those filaments. We propose to fully and precisely map the CO32/CO10 line ratio. In order to achieve this scientific objective, we already observed both lines with ALMA and ACA. However, we recently discovered that even ACA does not fully recover all the extended CO(3-2) emission: only half of the flux measured by APEX is retrieved. It is thus very likely that ACA does not fully recover the CO(1-0) emission either. We therefore propose to observe both the CO(1-0) and CO(3-2) lines with the ALMA Total Power only. It is the only facility able to map the full filaments with the needed sensitivity in a reasonable amount of time. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 2022-05-18T20:24:10.000
53 2016.1.00951.S 11 Filaments and Massive Star Formation The filamentary nature of the interstellar medium and molecular clouds sparks many questions about the mass assembly of molecular clumps and the formation of dense cores within them. We investigate a nearby, cold, and massive (1300 Msun) clump embedded in the infrared dark cloud G350 in the NGC 6334 star-forming complex. The molecular line emission from NH2D and H13CO+ as well as 3mm continuum traces gas at different evolutionary stages and at a range of densities. The sensitive ALMA observations will probe the mass accretion and fragmentation of molecular clumps and dense core formation. The data from this study will inform development of theoretical models of massive star formation. High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2018-04-25T19:44:05.000
54 2018.1.00081.S 57 The first measurement of a metallicity gradient in a dust-obscured galaxy at z=4 We propose 0.2arcsec(1.3 kpc)-resolution observations of [OIII]88 and [NII]205 lines for one of the best-studied submillimeter bright galaxies (SMGs) at z = 4.34, following our successful high-resolution observations of CO(4-3) and [CII] lines. The target, COSMOS-AzTEC-1, is a very massive, star-forming galaxy and the CO emision is concentrated on the central 1 kpc region, suggesting that AzTEC-1 is the most likely progenitors of compact quiescent galaxies at the peak of the cosmic star formation history. If the concentration of molecular gas is caused by an infall of pristine gas into the central 1 kpc region, we would see a deficit of metal-rich gas in the center. If not, metal-poor gas would be accreted onto the surrounding disk, supporting a scenario that the most massive galaxies grow from inside out. The primary goal of this proposal is to measure the gas-phase metallicities in the very bright, compact SMG using [OIII]/[NII] ratio. We will for the first time explore the metallicity gradient in such a heavily dust-obscured galaxy to constrain the scenarios of gaseous processes. Sub-mm Galaxies (SMG) Galaxy evolution 2019-12-18T11:59:02.000
55 2021.A.00031.S 30 The puzzling JWST object timely distangled by ALMA: Dusty starburst at z~5 or Ultra high-z galaxy at z~17? JWST has sparked a revolution of effort to discover and study galaxies at very early cosmic epochs. In particular, remarkably bright z~17 galaxy candidates are identified from several teams, which, if real, defies every early galaxy evolution model that assumes Lambda CDM cosmology. However, the latest study reports a tentative SCUBA2 850um detection from one of these candidates and shows that a z~5 dusty starburst galaxy with strong nebular emission lines can make its JWST/NIRCam broadband photometry at 1-5um resemble the extreme high-z galaxy SED. Here we propose a timely 1-hr ALMA Band 7 follow-up via DDT for such a z~17 galaxy candidate to confirm/rule out the lower-z scenario. Rather than waiting for the regular call, validating the robustness of first galaxy candidates at the farthest frontier is of urgent importance to the community in designing the next generation of follow-up observations, including ALMA cycle10 in April 2023 and JWST cycle2 in January 2023. Given this aspect, we waive the proprietary period of this DDT program. Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) Galaxy evolution 2022-09-21T23:21:49.000
56 2016.1.00550.S 33 (How) do very massive stars form in our Galaxy? Sgr B2 is the densest region of star formation in the Galaxy, and it is therefore the most likely to form the most massive stars in the local universe. Such proto-very massive stars (proto-VMS) may accrete from significantly different structures than the ordered disks we are accustomed to observing around nearby low-mass stars. We propose ALMA long-baseline observations to identify these structures and determine their masses and kinematic properties. We will determine whether the most massive stars, at least in our Galaxy, form by a scaled-up process similar to low-mass stars or by a more complex competitive or cooperative accretion process. We will also search for clues about whether stellar mergers are responsible for creating VMS. High-mass star formation, HII regions ISM and star formation 2018-10-13T18:53:40.000
57 2021.1.00181.S 11 Molecular gas and obscured SFR in a typical sub-L* galaxy at z=6 Accurate estimates of the mass and properties of the cold gas in distant normal star-forming galaxies are the key to understand how they grow, but also a challenge at z~3-6 due to their faintness. Here we propose an in-depth analysis of a strongly lensed sub-L* galaxy at z=6 to measure its molecular gas and obscured SFR content. The [CII] emission securely identified two lensed images in the ALMA Large Cluster Survey due to their magnification (20-160). The target is intrinsically faint and representative of low-mass galaxies at the end of reionization (M*~1e9 Msun, SFR~5 Msun/yr, much lower than any [CII]-detected source at z~6). We will (1) determine the molecular gas mass using [CI](2-1) and the dust in the Rayleigh Jeans tail, cross-calibrating the estimates from [CII], CO(1-0) (scheduled at VLA), and the dynamical mass (with ALMA+approved JWST); (2) estimate the obscured SFR via the LIR-L'CO(7-6) relation and by modeling the dust emission; (3) provide a benchmark (also on resolved scale) for the ISM conditions and the dust temperature in typical sub-L* galaxies at z=6 with CO/CI/CII and continuum ratios, creating a reference template for future studies of statistical samples. Gravitational lenses, Galaxy structure & evolution Cosmology 2023-02-08T16:41:28.000
58 2017.1.00545.S 57 How to form high-mass stars in proto-clusters? Although high-mass stars (M >8 Msun) play a major role in the evolution of galaxies, their formation and evolution are still very unclear. The two particularly promising models of high-mass star formation are "turbulent core accretion" and "competitive accretion" (see reviews in Krumholz & Bonnell 2009; Tan et al. 2014). In order to distinguish from different models for high-mass star formation, we propose to use ALMA 12-m array to mosaic 11 protoclusters. We aim to: (1). Study the spatial distributions of individual cores and their mass assembly in the protoclusters; (2). Study infall motions of individual cores with inverse P-Cygni profiles in HCN (4-3) and HCO+ (4-3) lines (3). Reveal the population of low-mass protostellar cores to see whether low-mass stars form along with their high-mass counterparts. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2019-08-14T05:18:39.000
59 2016.1.00580.S 32 Confusion-free Mapping of the Node within the Cosmic Web at z = 3 The z=3.09 SSA22 proto-cluster is one of the densest field at z>2 and therefore provide an unique laboratory to understand how galaxies and supermassive black holes (SMBHs) are formed and evolved in such extreme environment. In ALMA Cycle 2, we mapped a 2'x3' region of the proto-cluster core at 1.1mm, which results in the discovery of incredibly elevated star-forming and accretion activity at the 'node' of the 50 Mpc scale 'cosmic web'. Furthermore all of the dusty starburst galaxies are along the extensively extended Lyman-alpha filaments. To uncover the dust-obscured activity at the heart of the large-scale structure thoroughly, we propose to map an additional 4'x3' region, including the density peak of the proto-cluster. Utilizing the combined 20 arcmin^2 'ALMA Deep Field', we will (i) unveil the nature of dusty star-forming galaxies (number counts, clustering, the relation to the Lyman-alpha filaments, contribution to the cosmic star-formation rate density), (ii) characterize dusty activity in various populations via stacking analysis, and (iii) uncover how galaxies and SMBHs are co-evolved within the proto-cluser core. Starburst galaxies, High-z Active Galactic Nuclei (AGN) Active galaxies 2018-08-02T12:02:24.000
60 2019.2.00035.S 9 Understanding how CI, CO and dust trace molecular gas in z=0.35 normal star forming galaxies We propose CI(1-0) and dust imaging in 6 galaxies at z=0.35 which are part of a sample imaged in Cycle 1 at higher angular resolution. Our Cycle 1 project (2012.00978.S) was the first set of observations of dust, CO(1-0) and CI(1-0) in 12 normal galaxies, forming a statistically complete sample selected at 250 microns, and aims to determine a calibration for molecular gas using all three tracers for the first time. The Cycle 1 results are surprising, with 50% showing disturbed kinematics, either due to interactions with small satellite companions or potential outflows. The range of L_CI/L_CO ratios spans the full range of values seen in quiescent clouds in the Milky Way to extreme SMG and QSO, yet these galaxies are unremarkable systems with 11.1< Log Lir < 11.7, and so we do not understand what drives this variation. The limitations of Cycle 1 mean we have very different u-v coverage for the band 3 and 7 data-sets, therefore we request Band 7 ACA for the CI and dust in 6 sources with extreme CI/CO ratios, or where the CI and dust emission may be missing flux in extended structures. These ACA data will enable a robust morphological comparison between the CO, CI and dust emission. Spiral galaxies, Merging and interacting galaxies Local Universe 2021-04-09T12:39:18.000
61 2017.1.00575.S 28 Measuring line width of RRL from BLR of the Circinus galaxy We propose to measure the line widths of radio recombination lines (RRLs) (H35a, H36a, H40a, and H42a) from broad line region of the nearby type II galaxy Circinus. Broad line emission of RRLs (H35a, H36a) in Circinus had been detected with the Cycle 3 data with limited velocity coverage, which caused the difficulty of deriving the line widths of broad RRLs. Thus, we propose to re-observe the RRLs (H35a, H36a) with two overlapped frequency tuning to have about twice velocity coverage than that in Cycle 3. Observations of H40a and H42a are also proposed to confirm the broad lines of RRLs, as well as to derive the pressure broadening, which can be used to determine the density of electron density in the broad line region. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2018-11-16T17:19:25.000
62 2019.1.00720.S 24 Doubly deuterated water toward isolated and clustered protostars Understanding the evolution of water during star formation, from the molecular cloud down to the protoplanetary disk, is a central goal of astrochemistry. The amount of deuterated relative to non-deuterated water (D2O/HDO and HDO/H2O) traces the physical and chemical evolution of water because H2O is predominantly formed in the molecular cloud while deuterated isotopologues form later in the dense core phase. As a consequence, the D/H ratio of water should differ between isolated and clustered protostars since collapse time-scales depend on physical properties of the local environment such as density and temperature. We propose to observe the D2O transition at 316.8 GHz toward three isolated and two clustered protostars. HDO and H2O column densities have previously been measured toward the five sources allowing for direct comparison between the D2O/HDO and HDO/H2O ratios. Comparing the HDO/H2O and D2O/HDO ratios will provide critical feedback to chemical models, improve our understanding of the water evolution during star formation, and show the impact of the local cloud environment on the physical and chemical evolution during star formation. Low-mass star formation, Astrochemistry ISM and star formation 2021-01-24T14:50:22.000
63 2013.1.01292.S 126 An ALMA survey to unveil the main mode of star formation in the early Universe In recent years, convincing evidence have been accumulated that galaxies built up their stellar mass through a steady, diffuse and inefficient gas conversion dominantly taking place in non-interacting disk dominated galaxies. This has been confirmed at least up to z~3, beyond that even the deepest Herschel and JVLA surveys are not able to probe deep enough in L_IR sensitivity to detect normal massive galaxies. Thanks to exceptional ALMA sensitivity we are now in the position to easily detect a statistical sample of normal star forming galaxies at z~4 and test, for the first time, if the secular mode of stellar mass growth extends over all cosmic time. Starburst galaxies, Galaxy structure & evolution Active galaxies 2015-11-06T14:21:57.000
64 2015.1.01541.S 23 Anchoring Spiral Galactic Magnetic Fields in Molecular Clouds The formation of molecular clouds is poorly understood. Many cloud formation models assume that a large-scale galactic magnetic field is irrelevant at the scale of individual clouds, because the turbulence and rotation of a cloud may randomize the orientation of its magnetic field. The only observation of cloud fields in a face-on galaxy (M33, Li & Henning, Nature, 2011), however, supports the opposite picture: galactic fields could be strong enough to impose their direction upon individual clouds, thereby regulating cloud accumulation and fragmentation. Our location in the disk of the Galaxy makes an assessment of the situation difficult and observations of clouds in face-on galaxies are necessary. Only ALMA can offer the resolution and sensitivity to survey magnetic fields of clouds in face-on galaxies using the polarization of thermal dust emission. In this proposal, we start with NGC 628, a bright grand design spiral galaxy in the southern sky. Spiral galaxies Local Universe 2018-02-16T01:10:49.000
65 2018.1.00799.S 98 What is the role of angular momentum in disk formation? Comparing big and small disks around Class 0 The existence of large and massive disks around Class 0 protostars is hotly contended, both observationally and on theoretical grounds. One of the key parameters to constrain the disk formation is the radial distribution of the specific angular momentum, which is directly related to the maximum size of a Keplerian disk. We propose to observe 2 Class 0 objects with very different disk properties with ALMA in Band 3 to determine the dense gas kinematics. These observations will provide a unique dataset to determine the angular momentum profile form 10,000 au down to ~500 au for both sources. These results will establish if the difference in the disk size between these two sources is due to the initial conditions of the parental dense core. Low-mass star formation ISM and star formation 2020-02-19T22:24:20.000
66 2015.1.00551.S 44 Mechanism of Material Feeding to the Planet-Forming Disk in HL Tau We propose ALMA observations of HL Tau in the C18O (2-1), 13CO (2-1), and SO (6_5-5_4) lines at Band 6, and the HCN (1-0), HCO+ (1-0), and the SO (3_2-2_1; 4_5-4_4) lines at Band 3. The ALMA discovery of ringlike gaps in the circumstellar disk around HL Tau implies the ongoing planet formation. Our recent work using the ALMA long baseline data identified both the inner (r~100 AU) disk in Keplerian rotation and the outer envelope in the infalling motion. The infalling velocity appears to be slower than the free-fall velocity, though the missing short-spacing information and contamination from the associated outflows hinder us from unveiling the gas motion unambiguously. Here we propose to perform ALMA observations to sample the shorter spatial scales and combine the data with the long-baseline data, to unveil the mechanism of material feeding from the envelope to the planet-forming disk. We will also observe the optically-thin C18O line to avoid the outflow contamination, and multi-transitional SO lines to study the physical conditions of the accretion shocks at the transitional region from the envelope to the disk. Low-mass star formation ISM and star formation 2020-10-20T00:00:00.000
67 2015.1.00242.S 570 BASIC: A Bright ALMA Survey of SMGs in the Chandra Deep Field-South We propose an ALMA survey of a large, uniformly selected sample of 76 bright SMGs (~1 source per 1.5 arcmin^2) discovered with SCUBA-2 down to the confusion limit of S(850um)>2 mJy in the GOODS-S/CDF-S. These observations will bridge for the first time the critical transition range in SFR (~500 M_sun/yr) between the rare hyperluminous, dusty, optically faint galaxies found in shallow, wide-area submm surveys (e.g., LABOCA, HATLAS, SPT, Planck) and the extinction-corrected UV-selected Lyman Break Galaxies that are being probed with direct ALMA observations of small areas. These two populations are essentially disjoint, and key physical changes in star formation mechanisms may be occurring over this SFR range. ALMA observations of our SCUBA-2 sample will allow us to determine what fraction are single or multiple sources, measure their physical sizes and morphologies, pinpoint optical, NIR, and X-ray counterparts, construct spectral energy distributions, and estimate SFRs for these unique sources. Starburst galaxies, Sub-mm Galaxies (SMG) Active galaxies 2018-01-10T00:00:00.000
68 2016.1.00790.S 144 Constraining Quenching Processes in Galaxies Significantly Below the Main Sequence at z~0.7 Large surveys have shown that most galaxies fall along a well-defined relationship between star formation rate (SFR) and stellar mass. An increasing fraction of low-redshift massive galaxies have markedly depressed SFRs, but the physics of this "quenching" are poorly understood. Proposed quenching mechanisms imply very different, testable predictions for the molecular gas properties. If the decrease in SFR is due to bulge formation, massive galaxies can have high gas masses but long depletion times, but if quenching is due to gas depletion, we expect low gas fractions and short depletion times. We propose to measure molecular gas masses in a sample of massive z~0.7 galaxies with SFRs 3-10x below the main sequence. These objects are selected from the LEGA-C survey of galaxies with ultra-deep VLT spectroscopy, and span a range of colors, dynamics and stellar ages. We will extend gas scaling relations to the quiescent population at z~0.7, when the red sequence is actively being assembled. Our results will provide valuable constraints on theoretical quenching prescriptions, and reveal whether tension observed in the local quiescent population improves or worsens at moderate redshift. Galaxy structure & evolution Galaxy evolution 2018-02-24T21:37:31.000
69 2012.1.01011.S 8 Nature of the pre-brown dwarf core Oph B-11 The origin of brown dwarfs (BDs) is an important astrophysical mystery because its solution can also shed light on how a broad range of objects, from typical stars to giant planets, are formed and gain their masses. Using the IRAM Plateau de Bure interferometer (PdBI) at 93 GHz, we have recently identified the first bona-fide example of a pre-brown dwarf core, a self-gravitating starless condensation of gas and dust in the brown-dwarf mass regime (André, Ward-Thompson, Greaves 2012, Science, 337, 69). Given the current uncertainty in its radius (< 460 AU) and mass (~20 MJup), this object (Oph B-11) may even turn out to be the precursor to an isolated planetary mass object. Our result tends to support models according to which BDs form in a similar manner to normal stars, from the direct collapse of a prestellar core. We propose ALMA Cycle 1 observations in Band 3 (93 GHz), Band 6 (220 GHz), Band 7 (370 GHz), and Band 9 (670 GHz), in order to obtain robust measurements of the size, structure, mass of Oph B-11, and constrain its levels of rotation, infall, outflow motions. Such measurements may serve as benchmarks in future surveys for pre-brown dwarfs in nearby clouds, which will be necessary to assess whether most BDs originate from ultra-low-mass cores such as Oph B-11. Low-mass star formation ISM and star formation 2016-02-14T21:05:00.000
70 2019.A.00006.T 39 Diagnosing the Heart of an Old Supernova Recent observations emphasize the need to invoke a central engine in a growing number of supernovae to be able to explain the energetics. The most common model for this engine is in the form of a rapidly spinning pulsar remnant that imparts its energy to the supernova ejecta as it spins down. This pulsar should produce pulsar wind nebula (PWN) emission from its strong ionized wind. Although the supernova ejecta should initially be optically thick to this emission, it is expected to become visible in the years to decades after explosion. Here, we propose 84 minutes of ALMA observations at Band 3 and Band 7 to investigate a supernova that shows strong indications of an emerging PWN emission. If this is the case, then this will be the first time that we can actively monitor a pulsar and its pulsar wind nebula from the time of formation. Supernovae (SN) ejecta Stars and stellar evolution 2020-08-19T19:03:19.000
71 2022.1.01786.S 0 The heating mechanism for the cool, far-IR emitting dust in AGN In order to understand the links between AGN and galaxy evolution, it it important to determine precise star formation rates (SFR) for the AGN host galaxies. Far-IR luminosities are often considered to provide a "clean" diagnostic of the SFR. However, recent work has suggested that emission from the kpc-scale NLR or outer parts of the circum-nuclear torus can make a major contribution, and perhaps dominate, the far-IR continuum. Therefore, we propose to use the unique capabilities of the ACA to make a decisive test of the idea that AGN-heated cool dust is important at far-IR wavelengths by using Band 9 (680GHz) observations to image three nearby radio AGN. If the far-IR emission proves to be emitted by extended cone-like structures aligned along the axes of the large-scale radio structures (i.e. following the morphology of the NLR) this will provide clear evidence for a major contribution of the NLR at far-IR wavelength. On the other hand, in the case of a dominant torus component, the far-IR emission will be concentrated in a nuclear point source. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2024-09-08T21:44:39.000
72 2019.1.00021.S 36 The structure of the detached shells around DR Ser, V644 Sco, and S Sct In Cycle 6 we proposed to observe the detached shells around the carbon AGB stars DR Ser, V644 Sco, and S Sct in CO(1-0) to determine the evolution of the mass loss from AGB stars during and after a thermal pulse. To recover the flux on all scales, the Cycle 6 observations required two main-array configurations. The extended configuration at 1" resolution was observed in Cycle 6. We here request to observe the remaining configurations to create a complete dataset that is essential to correctly determine the creation and evolution of the detached shells. The shells span the entire age range of known detached shell sources, allowing us to constrain the mass-loss rate shortly after the thermal pulse, and to follow the evolution of the shells until they get photodissociated. Un unexpected velocity-splitting of the shells in the Cycle 6 data further confirm that the data will constrain the hydrodynamical properties of the shells. The proposed observations will yield the most detailed view of the evolution of the mass loss throughout the TP cycle on the AGB, and will constrain critical aspects of late stellar evolution, and hence of the chemical evolution of stars and the ISM. Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure Stars and stellar evolution 2021-03-27T13:03:41.000
73 2016.1.00985.S 19 Dense Core Magnetic Fields in High-Mass Infrared Dark Clouds High-mass Stars are cosmic engines known to dominate the energetics in galaxies. However, their formation is still not well understood. Massive, cold, dense clouds, often appearing as Infrared Dark Clouds (IRDCs), are massive stellar nurseries. No measurements of magnetic fields in IRDCs in a state prior to the onset of high-mass star formation (HMSF) have been available until very recently. Only studies of early stages can constrain the initial conditions for HMSF. We now reported observations of magnetic fields in two of the most massive IRDCs. We show that G11.11-0.12 and G0.253+0.016 are strongly magnetized. This shows that magnetic field is as important as turbulence and gravity for HMSF. We now propose to study the field on sub-parsec scales where the gas fragments into cores that form stars. To do so we pick dense cores within these unique unperturbed IRDCs. The interpretation of observations is supported by extensive custom--made numerical simulations of magnetized clouds. Combined with near-IR, far-IR and submm polarization data on larger scales, these observations will provide the first panoramic view of the magnetized nature and thus initial conditions of HMSF. Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2018-05-15T16:51:01.000
74 2021.1.00726.S 16 Constraining the Interstellar Medium Properties of the Most Luminous Galaxy Known At a redshift of 4.601 and with a luminosity of Lbol = 3.5 x 10^14 Lsun, the obscured quasar WISE J22460526 (W2246) is the most luminous galaxy detected to date. ALMA observations of the [CII]158um emission line have revealed a uniform, highly turbulent interstellar medium (ISM) that is being blown away from the host galaxy isotropically, likely due to the energetic feedback from central AGN. Deep observations of the 212um dust continuum further revealed that the gas reservoir at the center of W2246 is being fed by a multiple merger process, while [NII] observations point to an extremely dense ionized medium. However, there are many ISM properties of this outstanding source that are still unknown. Here we propose to obtain ALMA observations of the [OIII]88um emission line in W2246 at an angular resolution similar to that of the existing line dataset, ~0.3". When combined with the wealth of far-IR emission lines already in the ALMA archive, these observations will allow us to fully characterize the properties of the gas in a galaxy that represents the ultimate laboratory for studying and model the ISM physics and kinematics under strong feedback at high redshift. High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution Active galaxies 2023-12-20T17:27:06.000
75 2017.1.01358.S 52 C+ Emission from Luminous and Normal LAGER Lyman Alpha Galaxies at z=7 We will observe the [CII] line for 6 Lyman-alpha emitters at z~7 from our LAGER survey. LAGER is the largest volume narrow-band survey at this redshift. The current sample is from a 1.2 million cubic-Mpc survey, which we aim to extend to 10 million cubic-Mpcs. After more than 12 nights of imaging and 3 of optical spectrosocopy we have a uniformly selected sample of 27 high confidence LAEs. We see an excess of highly luminous (L > 3 L*) LAEs. This parallels the change seen at the bright end of Lyman-break galaxies but is more dramatic. Do we have an excess of luminous LAEs because star-formation properties of galaxies have changed at cosmic dawn? or is it because the luminous galaxies form an ionized bubble in the local IGM, allowing Lyman-alpha to escape? [CII] observations will probe kinematics and dynamical masses, measure SFR independent of LyA, and measure velocity offsets between LyA and [CII] to test reionization. We will observe the [CII] line in three luminous and three "normal" Lyman-alpha emitters. This will double the number of galaxies at Z>6 where both LyA and [CII] have been observed, and will be the largest LyA selected sample at z=7. Lyman Alpha Emitters/Blobs (LAE/LAB) Galaxy evolution 2019-02-27T19:31:11.000
76 2022.1.01771.S 8 Resolving the feedback action of cosmic rays in distant star-forming galaxies The exact role cosmic rays (CRs) play in mediating feedback within galaxies is a pressing question. We propose high resolution ALMA Band 7 observations of redshifted OH+, H2O+ and CH+ absorption lines from a galaxies at z~2.2, which has previously been found to exhibit an inside-out radial quenching pattern in its star-formation. This will reveal the interaction patterns of CRs within their host galaxy on 0.5 kpc scales. Accompanied by existing H-band VLT observations to trace the star-formation within this galaxy, the requested data will demonstrate the impact of CR quenching in shaping the evolution of this system, and will capture the importance of CRs in bringing about the downfall of star-formation in galaxies during the cosmic noon. Starbursts, star formation, Outflows, jets, feedback Active galaxies 2024-04-26T04:37:21.000
77 2017.1.00568.S 27 Water masers toward IRAS16293-2422 Water masers offer the possibility to diagnose gas motions in the disk and outflow of deeply embedded protostars at incredibly high angular precision, even by ALMA standards. Traditionally the 22 GHz transition was used for observing masers, and the observations reveal how dense and hot gas (n~1e8 cm-3, T~1000K) moves over timescales of years in both jet/outflow shocks as well as the disk surface on <10AU scales. ALMA is now opening the window to observing the 183 GHz H2O transition, a significantly lower-excited maser than that at 22 GHz (n~1e6 cm-3, T~150K). These lower pumping conditions imply that the maser is more readily excited in protostellar systems, where such physical conditions are much more prevalent than those required to pump the 22 GHz maser. We therefore propose to undertake a pilot study of the 183 GHz maser toward the prototypical deeply embedded source, IRAS16293-2422, along with its H2-18O equivalent at 203 GHz. These observations will open up a new window for ALMA to track gas dynamics on the smallest scales. Outflows, jets and ionized winds, Low-mass star formation ISM and star formation 2019-10-09T12:54:16.000
78 2012.1.00524.S 6 Shaping the Outflows of Binary AGB Stars The required conditions for stars to evolve into planetary nebulae (PNs) continue to puzzle. Since PNs are found in a wide variety of shapes, processes that could sculpt circumstellar envelopes (CSEs) are being investigated. A binary companion will have a strong gravitational effect, but known binary AGB stars are rare. We propose to observe a small sample of confirmed binary AGB stars, covering a decisive range in binary separation, in order to determine the gravitational influence of a companion on the circumstellar morphology of the AGB primary. ALMA is the only facility with the necessary sensitivity and resolution to study the effects of binary interaction systematically. The data will be analysed using state-of-the-art 3D radiative transfer and the results will be compared to 3D Smoothed Particle Hydrodynamics (SPH) models of the gravitational interaction. By constraining the shaping effects we believe that long-standing questions regarding this important transitional phase can be answered, and that major advances in the study of late stellar evolution will be made. Evolved stars - Shaping/physical structure Stars and stellar evolution 2015-05-07T18:41:06.000
79 2011.0.00017.S 0 Expanding the frontiers of chemical complexity with ALMA The search for complex pre-biotic and biotic molecules in the interstellar medium (ISM) will be a primary focus of ALMA science. The molecular inventory of meteorites found on Earth includes more than 80 distinct amino acids (the building blocks of proteins), and their composition suggests an interstellar origin. The key search site for new complex organics in the ISM is the hot dense core Sgr B2(N), due partly to its high column density. However, the firm identification of new molecules requires a robust spectral model to unweave the emission lines of weakly-emitting, more complex, species from known molecules. We have already constructed a unique model of this kind, using our previous single-dish line survey, which has already allowed our team to uncover several new species. We propose to use ALMA Early Science to perform a deep, unbiased line survey of Sgr B2(N) in band 3 (8 hours observing time). The proposed survey will improve the detection threshold for complex organic molecules by nearly a factor of 20 compared to our previous survey of this source. Such a sensitivity improvement should lead to the firm detection of a few, perhaps a dozen, new complex organics, while the adaptation of our existing spectral model will allow a rapid turn-around from detection to publication. The use of our team's cutting edge chemical models will allow the broader implications of new discoveries to be understood, and place strong constraints on chemical formation pathways. The discovery of biologically-relevant molecules in the ISM will be of high scientific impact, and is of broad appeal to the public and the media. The combination of ALMA's unique spectral sensitivity with our established methodologies will provide an efficient showcase of ALMA's capabilities in this field. Inter-Stellar Medium (ISM)/Molecular clouds, Astrochemistry ISM and star formation 2014-09-12T00:00:00.000
80 2011.0.00131.S 0 Piecing the shell together: ALMA and the detached shell around R Scl Spherically symmetric and very thin shells of gas and dust have been observed around about a dozen of carbon AGB stars - evidence that these stars have undergone episodes of major mass-loss eruptions. The origin of these detached shells is likely connected to the changes in mass-loss rate and expansion velocity during a He-shell flash. Recurring He-shell flashes are responsible for the chemical evolution of the star, the circumstellar envelope, and eventually the interstellar medium. We propose to observe the detached shell around the carbon AGB star R Scl using the compact configuration of the ALMA early science array in the CO(1-0), CO(2-1), and CO(3-2) transitions in bands 3, 6, and 7, respectively. The images from the ALMA observations will give unique information on the structure and evolution of the gaseous detached shell, and allow to determine the change in the physical stellar parameters during a He-shell flash. The observations will hence shed light on the origin of highly episodic mass loss and the He-shell flash phenomenon, as well as the mass-loss mechanism on the AGB and the structure of the circumstellar medium. Asymptotic Giant Branch (AGB) stars Stars and stellar evolution 2012-12-06T16:08:24.000
81 2013.1.00163.S 33 Masses of Low Mass T Tauri Stars We propose to measure the masses of young (<10 MY old) low-mass (<0.5 solar masses) stars by the rotation of their circumstellar disks. The improvements in the understanding of the evolution of young stars that result from the proposed research will enable astronomers to obtain a more reliable understanding of the mass spectra of the stars produced in star forming regions and of the chronology of their formation. Disks around low-mass stars Disks and planet formation 2016-12-12T00:34:50.000
82 2021.1.00222.S 5 The origin of Argonium (ArH+) ABSTRACT: Among the many hydrides detected in the interstellar medium, the molecular ion ArH+ is uniquely expected to reach observable abundances only in nearly pure atomic hydrogen regions with less than 0.1% H2. Previous observations of ArH+ emission associated with the supernova remnant Cas A and ArH+ absorption along Galactic sightlines toward distant star-forming regions have allowed the identification of ArH+ and the evaluation of its column densities. However, due to the complexity of the velocity structure and the presence of large amounts of H2-bearing gas, information on the intrinsic ArH+ line profile and the in situ abundance of ArH+ cannot be extracted from the data. We propose to observe the ground state ArH+ transition at 617.5 GHz toward the radio loud quasar and bright ALMA calibrator 3C454.3 where there are exceptionally complete observations including optical NaI, KI, CaII absorption along with HI, OH HCO+, CO and many other molecules, tracing the cold and warm gas phases. The proposed observation will allow us to identify in a unique way the conditions under which ArH+ exists in the ISM and which phases of the atomic gas are traced by ArH+. Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2023-07-29T20:42:51.000
83 2022.1.01215.S 364 Revealing Protocluster Growth Around Powerful Radio Galaxies Across Cosmic Noon High redshift radio galaxies (HzRGs) are thought to pinpoint the cores of galaxy protoclusters. Yet, to date, there remains significant confusion about the Mpc-scale overdensities of obscured star formation around HzRGs. To remedy this situation, we reduced SCUBA-2 850micron data of 30 HzRGs at z=1-4.5, finding the central 6Mpc regions to be >5x overdense in submillimeter sources (SMGs) compared to the field. This depends critically, however, on spectroscopic confirmation and whether bright SMGs break into fainter sources at higher angular resolution. We propose ALMA Band-5/-6/-7 observations (FWHM~1-2") targeting CO(7-6) and [CI](2-1), and the continuum, in the 10 brightest SMGs in 10 HzRG fields (100 SMGs in total) across the Cosmic Noon (z=1.5-3.5). This will resolve the critical issues of redshift and source multiplicity, required to accurately quantify the SMG overdensities around HzRGs. It will provide unambiguous identifications in existing OIR data, allowing us to infer key physical properties of the SMGs. The outcome will be the first systematic study of SMG-overdensities and their evolution with redshift, and the physical properties of SMGs in overdense regions. Sub-mm Galaxies (SMG), Galaxy Clusters Galaxy evolution 2024-01-11T12:16:07.000
84 2015.1.01107.S 7 Is precipitation driving radio mode AGN feedback in giant ellipticals? The nature of the material accreted onto the supermassive black holes (SMBH) at the hearts of active galactic nuclei (AGN) with radio mode activity remains one of the outstanding questions of accretion physics. In particular, it is not clear whether the accretion in massive early type galaxies proceeds from the hot X-ray emitting interstellar medium (ISM) or from the accumulated cold ISM. Here we propose to map the CO line emission in NGC 4636, the nearest (d 14.7 Mpc) X-ray bright giant elliptical galaxy with a radio mode AGN and confirmed reservoirs of cold gas. This galaxy provides a unique opportunity to resolve the cold molecular gas on the smallest physical spatial scales in a radio mode AGN and map its distribution and the velocity structure down to the Bondi accretion radius of the central SMBH. In conjunction with existing multi-wavelength data, this pioneering observation will allow us to uniquely address the fundamental question: what is the nature of the material feeding radio-mode AGN? Is it cold or hot gas, or is the hot ISM undergoing a cooling instability before it is accreted onto black holes? Early-type galaxies Galaxy evolution 2018-11-11T04:39:12.000
85 2021.2.00102.S 0 Mapping the Large-Scale Flow of Material to a Protoplanetary Disk During Planet Formation Protoplanetary disks have traditionally been viewed as isolated reservoirs of planetary building blocks. However, recent detections of large-scale streamers and spirals associated with Class II disks suggest that they can continue to accrete material from their surroundings while planet formation is underway. Observations of the RU Lup system have revealed both non-Keplerian spiral arms and a large, nearby arc-like structure, raising the possibility that the arc-like structure is feeding the disk. To investigate whether the arc-like structure is supplying new material to RU Lup and to estimate the available mass, we propose an ACA mosaic to map RU Lup's surroundings in CO isotopologue emission. These observations will advance our understanding of how late infall can affect the mass, composition, and angular momentum of disks, and therefore the properties of planets forming within them. Disks around low-mass stars Disks and planet formation 2023-06-15T09:48:28.000
86 2016.1.01591.S 17 Ice in the embers: Testing the existence of cold molecular gas in a lensed compact quiescent galaxy at z=2.15 We propose for a CO(3-2) observation of a strongly lensed compact quiescent galaxy (cQG) where we find rotation and a compact exponential light profile, suggesting a disk galaxy. Otherwise, the proposed galaxy is a typical example of the population of compact cQGs, which have in the last couple of years been identified as an important piece in a consistent understanding of how galaxy evolves. The cQGs are widely believed to be dispersion-dominated bulges with an unknown quenching mechanism preventing further star formation, thus observing the molecular gas content will help unveil the true nature behind the cease in star formation. As the study of molecular emission from quiescent galaxies at z>2 is unprecedented, this can be considered a pilot study. Therefore, this observation is meant as a detection experiment and the observation time is chosen based on feasibility arguments and comparison to lower redshift post-starburst galaxies. Gravitational lenses, Galaxy structure & evolution Cosmology 2018-05-18T04:06:40.000
87 2017.1.01228.S 15 "Resolving" the Unusual Molecular Gas Excess in z=1.6 Cluster Galaxies We propose for 4.4 hours of spatially-resolved (0.3) CO (2-1) emission in gas-rich z=1.6 cluster galaxies. Our Cycle 3 program of unresolved CO emission has uncovered massive gas reservoirs in 11 clusters galaxies, constituting the largest sample of molecular gas in z>1 clusters to date. These data reveal systematically higher gas fractions than the coeval field. The physical origin of this gas excess is not clear, and high-resolution imaging is crucial to investigate the nature of the CO in high-z clusters. Our proposed ALMA Cycle 5 observations will yield the first glimpse of spatially resolved molecular gas in high-redshift cluster galaxies, mapping out asymmetric CO morphologies and providing insight on how distant cluster environments affect the gas for the very first time. Galaxy structure & evolution, Galaxy Clusters Galaxy evolution 2019-03-05T20:40:29.000
88 2019.2.00055.S 9 Tracing CO-dark molecular gas at low metallicity We propose an ALMA/ACA 850 micron continuum map of most of the star-forming area of WLM, a Local Group dwarf irregular galaxy with an oxygen abundance that is 13% of solar. In C1 we detected 10 tiny CO cores in two star-forming regions in WLM, and in C6 we mapped WLM in CO(2-1). The unprecedented resolution (18 pc) of the continuum map proposed here in combination with our other data (Spitzer, HI, CO, Halpha, FUV) will reveal the distribution of the cool dust at the scale of FUV clumps. From these data, we will get a first glimpse of the distribution of total H2 gas, its relationship to the CO cores and to young stars, and the nature of CO-dark gas at a spatial resolution of 18 pc and at 13% solar metallicity. This will shed light on the physical conditions under which stars form in a metal-poor environment, possibly similar to that in the early universe. Dwarf/metal-poor galaxies Local Universe 2022-10-19T19:25:24.000
89 2017.1.01002.S 31 Searching for hot molecular cores in the extreme outer Galaxy The recent discovery of a hot molecular core in a nearby low metallicity galaxy, the Large Magellanic Cloud (LMC), suggests that the galactic metallicity has a significant effect on chemistry of warm and dense molecular gas associated with a protostar. While remarkable chemical differences are reported for the LMC hot core, it is still unclear if the observed chemical characteristics is essentially common in other low metallicity environments or it is unique only in the LMC. Here we propose ALMA observations to search for hot cores in the star-forming region at the edge of our Galaxy. The proposed target, WB89-789, is an active star-forming region located at the extreme outer Galaxy (galactocentric distance ~20 kpc), where the metallicity is lower than the solar neighborhood by a factor of four. The low metallicity environment of the outer Galaxy, which is common with the LMC, provide us an ideal laboratory to test the universality of the low metallicity molecular chemistry observed in the LMC. This proposal aims to elucidate a possible link between metallicity and hot core chemistry, particularly by focusing on properties of complex organic molecules and their parental species. Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2019-09-21T16:02:49.000
90 2018.1.00641.S 3 Evidence of accretion disks during the formation of high-mass stars in the Central Molecular Zone The Central Molecular Zone (CMZ) in our Galatic Center is a unique high-mass star forming environment with extreme physical conditions. Whether accretion disks play a role in high-mass star formation in the CMZ in the same way as the Galactic disk regions is unclear. Our recent SMA, JVLA, and ALMA observations toward two massive clouds in the CMZ reveal four massive protostellar cores that may give birth to massive O-type stars, and tentative signatures of accretion disks are seen. To obtain critical evidence of accretion disks in these four cores, we propose to observe them with long baseline configurations to resolve them down to 300 AU. This will enable us to learn whether the formation of massive stars in the CMZ fits into the standard disk accretion model. High-mass star formation ISM and star formation 2021-12-31T00:00:00.000
91 2015.1.01205.S 26 The early coevolution of galaxies and black holes We propose observations of the dust continuum and of one high-J CO transition in six heavily obscured QSOs residing in SMGs at z>2.5 in the CDFS. All QSOs are obscured by an X-ray column density of NH>3e23 cm-2. Their hosts are massive (M*>1e11 Msun) and feature vigorous star formation rates (SFR>300 Msun/yr). Through band 4 observations with 0.3" FWHM resolution, i.e. half-light radius ~1 kpc at the median target redshift, we will measure the morphology and compactness of star formation and the mass and density of the ISM. With 5 hr of ALMA time (including overheads) we will assess whether: 1) star formation is taking place in a compact (~0.5-2 kpc) region, with size similar to that of compact quiescent galaxies (cQGs) at z<2. This, coupled to other physical quantities such as SFR, stellar mass, gas depletion time, would reveal whether our targets are the likely progenitors of cQGs; 2) the host gas density is so high that it can produce most of the nuclear absorption measured from the X-ray spectra. This might help explaining why the fraction of heavily obscured QSOs has been observed to increase with redshift. Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) Galaxy evolution 2018-05-05T23:31:18.000
92 2012.1.00453.S 32 Spatially resolved wide band spectroscopy in ULIRG obscured nuclei The successful line surveys carried out at low resolution towards the prototypical ULIRG, Arp220, have unveiled an unexpectedly rich chemistry. Not only it has been shown that Arp220 is likely the brightest and most prolific molecular extragalactic emitter, but its chemistry appears to reveal significant differences with respect to that found in nearby starburst galaxies. The high sensitivity and resolving power of ALMA opens the possibility of spatially resolving the chemistry of the two nuclei. Such observations will shed light on the individual chemical composition and physical conditions of each nuclei. We therefore propose to extend the study of the molecular composition of Arp 220 by scanning the ALMA bands 6 and 7. Apart from the determination of molecular abundances, we will be able to determine the line contribution to the continuum emission and the cooling rate of the whole system. Moreover, we will get the most detailed study of the excitation conditions of the molecular gas in an ULIRG. Galaxy chemistry, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Galaxy evolution 2015-07-30T18:49:44.000
93 2018.1.01753.S 16 Detecting the envelope surrounding the HH30 T-Tauri star We ask for ACA data to complement our ALMA-cycle 2 data-set on the T-Tauri star HH30 (see Louvet et al. 2018). HH30 is driving a bipolar jet, but a monopolar outflow. Our study of the outflow favors the models of MHD disk wind, that reproduce the best the parameters of the outflow. Nevertheless, we couldn't exclude that the outflow is created by a stationary interaction between the jet and the envelope of HH30. We were not able to detect the envelope with our ALMA-cycle 2 data and therefore request for a complementary larger-scale ACA data-set. Outflows, jets and ionized winds, Low-mass star formation ISM and star formation 2020-01-07T12:19:29.000
94 2019.1.00263.S 77 Explosive Outflows from Compact Groups of Forming Massive Protostars The OMC1 explosion, ~0.1 pc behind the Orion Nebula, was powered by an N-body interaction that ejected 3 stars as runaways ~550 years ago. We propose to image three other candidate explosive protostellar outflows in molecules, H30-alpha, and the 1.3 mm continuum. They contain fingers of shock-excited molecular hydrogen, bullets, and streamers similar to Orion OMC1. Their radial velocity structure will determine if they were powered by a nearly instantaneous explosion or a quasi-steady injection of energy by winds or jets. Their masses, momenta, and kinetic energies, the locations of their source stars, and dynamical ages will be measured. Explosive protostellar outflows represent a new type of feedback in cluster-forming regions that may contribute significantly to the self-regulation of star formation. They are signposts of violent, N-body interactions or major accretion events. N-body interactions that eject stars from their birth environment by more than a few km/s will terminate accretion, set the final masses of the ejected stars, and if common, may play an important role in establishing the Initial Mass Function (IMF) of stars. This program will constrain the event rate. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2021-03-10T20:17:41.000
95 2018.1.01077.S 0 Unveiling the enigmatic gas content of distant starbursting mergers The nature of high redshift galaxies with the highest specific SFRs (starbursts) is a lasting debate in the community. They could be very gas rich stream-fed objects, or very efficient star-formers, or a combination thereof. The debate cannot be solved unless reliable determinations of their alpha_CO and/or DGR ratio are obtained, allowing accurate measurement of gas masses of these systems that are mostly mergers. This could be only achieved via accurate determination of dynamical masses, a challenge for near-coalescence mergers. Our numerical simulations have shown that reliable dynamical masses can instead be obtained for interacting pairs, which retain their disk-like geometry, albeit with an intrinsic accuracy of ~0.2 dex. We propose to observe CO lines for 4 merging pairs at z>1.15 for which the total CO flux is already determined and strong. Together with another pair already in hand (Silverman et al 2018, submitted), these 10 galaxies will enable a statistical determination of the average alpha_CO and DGR in mergers to an accuracy of 0.1 dex. This will allow us to firmly determine dynamical masses in distant starbursts. Starburst galaxies, Galaxy structure & evolution Active galaxies 2021-01-07T15:02:39.000
96 2019.1.00700.S 51 Resolving water emission and dust temperature in the early universe We propose spatially resolve dust temperature and infrared luminosity in three strongly-lensed starforming galaxies at z~3 from the SPT survey. With the aid of gravitational lensing, we will achieve kpc spatial resolution in the source plane in B9 with 0.5 arcsecond angular resolution. The B9 continuum observations will enable us to spatially resolve the L_H2O/L_IR correlation and dust temperature in galaxies at high redshift for the first time. These observations will provide a powerful constraint on the kinematics of the FIR field and help understand the relation between star formation and star formation potential at high redshift. The water observations have already been conducted in Cy 3 & 4 and the result has been published in ApJ. Here we are requesting 49 minutes in Band 9 to complete the continuum imaging portion of the project. (This exact proposal was given an A-ranking in Cycle 5, but never observed.) Sub-mm Galaxies (SMG) Galaxy evolution 2021-03-13T22:28:53.000
97 2021.1.00765.S 0 Physical Conditions of SSC Formation in Henize 2-10 Super star clusters (SSCs) are consistent with being the progenitors of globular clusters, so understanding the conditions of their formation provides insight into star formation during the era of galaxy assembly. To understand the environment and conditions of SSC formation, it is essential to observe the earliest stages that are only observable at mm wavelengths, before stars form and disrupt the natal material. Johnson et al. 2018 identified a population of molecular clouds that may have the necessary properties to form SSCs in Henize 2-10, a dwarf starburst galaxy with several well-studied SSCs, but this data had too low a resolution to confirm them. This population includes clouds at a range of formation stages, including several with no associated thermal radio emission, indicating that massive star formation has not yet begun. Our proposed observations and non-LTE fitting technique will constrain the masses, sizes, temperatures, densities, substructure, and kinematics of these clouds. We will be able to confirm if this population has any pre-SSC clouds and compare the SSC formation process in a dwarf starbust to other environments, such as the major merger Antennae galaxies. Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2023-10-21T17:07:56.000
98 2018.1.01124.S 3 Resolving the SgrA* Accretion Disk at 2000 Schwarzschild Radii Using H30alpha Recombination Line In our previous observations with ALMA Cycle 3 and Cycle 4, we detected a broad, 2000km/s wide H30alpha emission line from within 0.008pc of Galactic Center black hole (SgrA*). The H30alpha recombination line emission provides a direct and reliable probe of the non-X-ray emitting ionized gas likely constituting the bulk of the accretion reservoir of SgrA*. The double peaked shape of the detected line indicates the presence of a few 10^-3 * M_sun disk composed of ionized H at temperature ~10^4K. The emission is partially resolved and extends to just under 0.2'' in radius. We propose a high resolution study of the HI recombination line emitting disk around SgrA*. ALMA capabilities are such that it would allow us to resolve the disk down to the scale of ~2000 Schwarzschild radii. This observation would open up an entirely new avenue to understanding the black hole environment, allowing us to perform a direct measurement of gas kinematics and initiate a new observation-based modeling of the process by which the black hole is fueled. Both will be key to resolve the mystery of supermassive black hole accretion in the galactic center. Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei Active galaxies 2021-04-30T00:00:00.000
99 2017.1.00125.S 17 Quasar Feedback in the Early Universe: Lowest Eddington Ratio Quasar at z~6 It has been found that quasars at z > 6 contain supermassive black holes (SMBHs) accreting mass at their maximal rates (Eddington ratio REdd ~ 1). However, it is suggested that their FIR emission is found to be unusually weak in comparison to their counterparts at lower redshifts, possibly due to a strong quasar feedback suppressing star formation in their host galaxies. Recently, we discovered a faint quasar at z ~ 6, IMS J2204+0112 with its REdd at only 0.07+-0.05. This finding suggests that there exist SMBHs with nominal accretion rates similar to lower redshift quasars, and that they may be a more general quasar population at z ~ 6. Here, we propose to study the FIR property of IMS J2204+0112, by performing the submm continuum observation at ALMA bands 6 and 7. ALMA is currently the only facility that can trace the faint FIR flux of J2204+0112 (expected to be 130 uJy) and the two band observation can produce a reliable estimate of FIR luminosity. The proposed observation will teach us for the first time how the star formation in host galaxies is linked to the black hole growth at z~6 for a quasar with nominal accretion activity. High-z Active Galactic Nuclei (AGN) Active galaxies 2019-06-07T19:31:03.000
100 2019.1.00564.S 11 Enhanced Molecular Oxygen abundance in galaxies with AGN molecular outflow We propose to observe red-shifted 118.75 GHz O2 emission as well as CO 2-1 toward one nearby AGN IRAS 10565+2448, in which molecular outflow had been detected with CO 1-0 observation. It will be the first well-imaged extra-galactic O2 emission, which will be an ideal tool for studying AGN feedback and understanding cooling and oxygen chemistry in molecular outflow. If O2 118.75 GHz line in IRAS 10565+2448 can be imaged within several hours, it will open a new window for searching molecular outflow in AGN, because outflows identified with CO observations can severely be contaminated by non-Gaussian components of the host galaxy. On the other hand, O2 emission from dense molecular gas in host galaxy can be neglected. If the enhancement of molecular oxygen in galaxies with AGN molecular outflow is a common phenomenon, such observations will be important to provide inforamtions of gas properties in O2 emiting regions for new chemical models of O2 formation. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2021-03-12T04:30:46.000
101 2021.2.00077.S 356 Tending the Fire: A Survey of Molecular Gas Fueling in Powerful Nearby AGN Despite 30 years of research, the role of cold, molecular, galaxy-scale gas in AGN fueling remains unclear. A large APEX survey of 213 of the brightest nearby (0.01 Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies Active galaxies 2023-01-25T23:10:44.000
102 2017.1.01117.S 56 Study of the first O-type 'bloated star' candidate 'Bloated stars' are high-mass young stellar objects whose stellar surface is expanding due to active accretion on to them. While this phase of massive star formation is firmly predicted by models, no clear examples of O-type stars have been identified yet in such a phase. IRAS 19520+2759 is, to our knowledge, the best 'bloated star' candidate with a luminosity > 10^5 Lsun, given its particular optical spectrum, lack of radio-continuum emission, its association with collimated outflow, and with an elongated, dense structure likely tracing a rotating structure perpendicular to the outflow. However, the association of the millimeter dense core and the optical star remains to be confirmed, and here we propose 0.15 arcsec angular resolution observations of the continuum at 1 mm (comparable to Hubble Space Telescope 0.1 arcsec resolution in the optical) in order to determine the position and morphology of the mm source. Simultaneous spectral line observations of dense gas tracers will allow to study the kinematics of the gas in the vicinities of the first O-type 'bloated star' candidate. High-mass star formation ISM and star formation 2019-10-12T09:41:44.000
103 2021.1.00754.S 14 Dissecting the circumstellar disk around the B-type protostar IRAS20126+4104 The existence of disk+outflow systems around early-type stars has been invoked by theorists to overcome the powerful radiation pressure by the star and allow the accretion onto the star to proceed up to 140 Msun. Despite their importance, only recently bona-fide disk candidates have been detected around B-type (>8 Msun) protostars. IRAS20126+4104 is by far the best of these. Both the close distance (1.64kpc) and the well studied disk+outflow system make this the ideal target for a high-resolution study with ALMA. With the proposed observations we will for the first time establish the rotation curve and disk physical parameters (temperature, column density) as a function of radius. Our observations will be a breakthrough, as little is known on the nature of the disks around B-type stars because the resolution attainable before ALMA was insufficient to properly resolve them. In particular, we will obtain the following: calculate the Toomre Q parameter as a function of radius and assess if the disk is stable, compute the stellar mass and accretion rate through the disk onto the star, and establish the presence of gaps and/or local instabilities, possibly induced by stellar companions. High-mass star formation ISM and star formation 2023-07-21T22:15:21.000
104 2013.1.00205.S 8 Smoking gun confimation of dusty nuggets as progenitors of the red nuggets at z~2 The discovery of the "red nugget" population (massive, compact, quiescent galaxies) at z=2 indicates that early passive galaxies were remarkably compact compared to their present-day elliptical counterparts. Recent observations have identified a population of compact, star forming galaxies (so-called "dusty nuggets") that appear to be the direct progenitors of the red nugget galaxies. While several pieces of indirect evidence link these two populations, ALMA observations will provide the smoking gun confirmation that dusty nugget galaxies are the star forming progenitors of the first generation of red sequence galaxies. Therefore, we request 3.7 hours on-source to obtain Band-7 luminosities and continuum maps on eight dusty nuggets to: (a) determine if their star-forming components are as compact as the stellar components of red nuggets, and (b) verify a short quenching (gas depletion) timescales consistent with the rapid build up the red nugget population. Galaxy structure & evolution Galaxy evolution 2016-11-17T23:21:09.000
105 2013.1.00955.S 60 Properties and evolution of embedded protostellar disks ALMA is already providing exciting results on how circumstellar disks form around low-mass young stars and how they evolve from the embedded through planet-forming stages. In this proposal we will attack the question: What is the relation between the formation and early evolution of circumstellar disks and the physics of the inner regions of collapsing protostellar envelopes? We will utilize ALMA's Band-7 to image a representative sample of 12 embedded protostars from the Ophiuchus star forming region in molecular lines from a selected set of isotopologues of common molecular species probing material with high temperatures and densities in the inner envelopes and circumstellar disks. This study will begin the process of assembling the key statistics required to understand the formation and early evolution of circumstellar disks, as well as provide key insight into the physics and timing of protostellar accretion. Low-mass star formation ISM and star formation 2016-08-25T12:33:45.000
106 2019.1.00246.S 152 Moving Past Small Number Statistics in Astrochemistry: A Molecular Survey of 25 Hot Cores Studies of chemical evolution have traditionally focused on a small number of exceptionally molecularly rich and bright sources due to the historical difficulty in detecting complex interstellar molecules. This small sample size biases our understanding of 'standard' chemical evolution, and prevents calibration of chemical models to standard conditions. Single-dish surveys that have attempted to address this issue by surveying substantially larger sample sizes have suffered from extreme beam dilution, due to the very small angular size of typical chemically rich hot cores. Here, we propose to exploit both the sensitivity and spatial resolution of ALMA to conduct a distance-limited survey of twenty five hot core sources. We target several spectral windows designed to provide the maximal scientific return, and will use the results to calibrate several of the industry-standard models and identify critical areas in which these models need refinement. High-mass star formation, Astrochemistry ISM and star formation 2022-08-24T00:00:00.000
107 2013.1.00535.S 21 Probing the AGN activity and molecular interstellar medium in ultra-luminous infrared galaxies using CH The goal of this proposal is to establish the CH/CO line ratio as a discriminator between AGN and star-formation dominated galaxies by observing CH (at 560 microns) and CO (J=1-0) in five ultra-luminous infrared galaxies, with and without AGN, at z ~ 0.1. In a small sample of local galaxies observed with the Herschel Space Observatory, we found that the CH/CO abundance ratio is almost an order of magnitude higher in an AGN-dominated galaxy (NGC 1068) compared to three starburst -dominated galaxies (Arp 220, M 82 and NGC 253). This is consistent with the higher abundance of CH expected in X-ray dominated regions, fueled by the presence of the AGN. In addition, estimation of the molecular hydrogen column densities from CH and CO will enable us to test whether the CH is coming from diffuse or dense gas, and thus its reliability as a mass tracer. With the end of the Herschel mission, observations of far-infared CH lines are impossible in nearby galaxies because of atmospheric water vapor. Band-8 of ALMA can detect these lines for galaxies at z > 0.08, the lowest possible redshift for which such a study can be performed. Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Active galaxies 2016-11-01T11:45:09.000
108 2016.1.01425.S 18 Resolved Imaging of Radio Photospheres We propose to obtain spatially resolved 1.3-mm imaging observations of the radio photospheres of a sample of four asymptotic giant branch (AGB) stars. Radio photospheres lie just inside the dust formation zone of these mass-losing stars, hence their study probes the region of the stellar atmosphere where the stellar wind is launched. Our previous imaging observations of radio photospheres with the VLA and ALMA show that their shapes are generally non-spherical, and there is now evidence that these shapes change on timescales of several months or more. New observations with ALMA will provide confirmation that the apparent shapes are not instrumental artifacts and will permit us to distinguish between possible origins for these shapes. The ALMA data will also probe deeper into the stellar atmosphere than shorter wavelength VLA observations, providing a measure of the change in temperature with radius. Finally, the ALMA data will uniquely permit detection and characterization of spots, convective cells, or other brightness non-uniformities across the radio surfaces of the stars. Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure Stars and stellar evolution 2018-10-10T09:03:06.000
109 2021.1.00739.S 32 Propagation of cosmic rays in molecular clouds interacting with a supernova remnant Cosmic rays (CRs) are a major component of the Galaxy. Especially, since low-energy CRs lose their energy via ionization, they are believed to have a strong influence on the chemical evolution in molecular clouds and on star and planet formation. However, the influence of CRs has been discussed only hypothetically in theories because the propagation process of CRs in molecular clouds is highly unknown. A recent study noted that CR protons with E~0.01 MeV, ~10 MeV, ~GeV attribute to the ionization rate, Fe I Ka line, and Gamma-ray emission, and indicated that the relative spatial distributions among the the three observables are the key to reveal the propagation process. Actually, there are no samples where the three observables were measured in the same region. We focus on the southwestern edge of the supernova remnant W44, where both the Fe I Ka line and gamma-rays are detected. We propose DCO+ (J=2-1) and H13CO (J=1-0) observations at two positions in this region to measure the ionization rate and its spatial distribution. This observation will reveal the propagation of MeV CRs observationally for the first time. Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2023-04-13T18:37:02.000
110 2012.1.00479.S 11 Imaging the molecular torus of the active galactic nucleus in the Circinus galaxy A toroidal distribution of molecular gas and dust is a key component in our current picture of active galactic nuclei (AGN). This so-called "molecular torus" is held responsible for the orientation dependent obscuration of the central engine, and it plays a fundamental role for the accretion onto the supermassive black hole. Despite its importance for our understanding of AGN, its physical properties remain unclear and its existence is still disputed. Using the unprecedented imaging capabilities at high angular resolution of ALMA, we propose to map the molecular material of the outer torus in the Circinus galaxy, the nearest Seyfert 2 galaxy. The observations of CO(3-2) and CO(6-5) in this showcase study will, for the first time, provide a model-free image and direct information on the geometry, morphology, kinematics and accretion flow of the molecular material on parsec scales in an AGN -- something which has not been possible since the torus paradigm was established 25 years ago. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2016-09-23T02:29:13.000
111 2023.1.00299.S 0 Resolved Multi-J CO/[CI] study of a strongly lensed, Planck-selected z = 2.66 dusty protocluster of at least 9 DSFGs We propose, for the first time in a gas-rich z>1 overdensity, a multi-line modeling of the [CI] / CO line and dust spectral energy distributions (SED). PJ0846 is an all-sky Planck selected protocluster consisting of 9 strongly lensed dusty star-forming galaxies (DSFGs) within 100 kpc at z=2.66. This analysis aims to determine the mechanisms driving SF in dense environments and search for evidence of quenching prior to halo mass assembly. Piecemeal archival data with limited sensitivity has sparked dedicated follow-up (0.1-0.2") observations of [CI], CO (3-2, 7-6) emission lines and ACA B9 continuum measurements to constrain the rise/fall of the CO ladder and the peak of the dust SED. What sets this project apart is: (1) PJ0846 is a lensed protocluster field with 9 DSFGs allowing high S/N multi-line and continuum studies, while removing an important systematic uncertainty in gas mass via modeling, and (2) an existing lens model will use the data to probe spatially resolved gas excitation conditions at 10 to 100 pc scales to examine intrinsic gas properties associated with this overdense burst of DSFGs within a protocluster environment at Cosmic Noon -- all within a single field. Starburst galaxies Active galaxies 2025-01-17T12:56:55.000
112 2019.1.01282.S 16 Constraining the sulphur chemistry through observations, lab experiments, and models Sulphur is one of the most abundant elements of the interstellar medium, and it is also one of the elements where the chemistry is the least understood. This means that although we can readily observe S-bearing molecules in practically every type of environment, we do not know enough that we can use the chemistry to inform us about the physical conditions. To remedy this, we here propose to observe eight different S-bearing molecules toward a shock position in BHR71, a source where atomic S is bright and where we have a chance to obtain a complete inventory of sulphur compounds. A shock position is in many ways the ideal laboratory to study the sulphur-chemistry, because species otherwise locked up on grain surfaces are liberated and observable in the gas phase. To understand the observations, we are carrying out state-of-the-art laboratory experiments. The results of these experiments are incorporated into sophisticated shock models. This unique approach puts us in an ideal position to finally start understanding the sulphur-chemistry in the ISM. Outflows, jets and ionized winds, Astrochemistry ISM and star formation 2021-03-25T04:53:33.000
113 2021.1.00310.S 3 Constraining dust growth in a strongly turbulent disk from polarization observations We propose to observe the polarization from the transitional disk around DM Tau to constrain dust fragmentation and planet formation. This object is the only source for which strong gas turbulence has been detected from line broadening of molecular line emission. The strong gas turbulence causes dust fragmentation, making it difficult to form planets. Therefore, we propose to determine the dust size from polarization observations in Band 7. Dust polarization observations provide a robust method for estimating the dust size, and we can determine the dust size whether the disk is optically thick or thin. If polarization is not detected, we can place strong limits on the dust size. This is a proposal for the first polarization observations of a disk with strong turbulence, and it will reveal the effects of gas turbulence on dust growth. We also propose to observe C17O line emission simultaneously with the polarization observations to trace the radial profile of the gas surface density. We can produce a moment 0 map without losing continuum sensitivity with our observational setting. Disks around low-mass stars Disks and planet formation 2024-01-30T07:36:54.000
114 2018.1.01405.T 78 Revealing the Structure and Magnetization of GRB Jets with ALMA Polarization Observations Polarization measurements of the luminous afterglows of long-duration gamma-ray bursts (GRBs) have long been predicted to probe the structure and magnetization of their relativistic jets, revealing the nature of their elusive central engine. While polarization of the reverse shock (RS) probes ordered magnetic fields in the outflow, polarized forward shock (FS) emission is sensitive to the jet angular structure and viewing geometry. ALMA Band 3 provides an ideal window to search for these polarization signatures, as the emission from the shocks is observable longer in this band than at higher frequencies, while being unaffected by interstellar scintillation and depolarization from self-absorption relative to lower frequencies. We propose a pilot ALMA full linear continuum polarization observation of a bright GRB afterglow in Band 3 to capture the radio polarization signature of GRB jets for the first time, aiming to constrain the magnetization, angular structure, and viewing geometry, and placing unique constraints on the central engine and jet acceleration mechanisms in these relativistic transients. Transients Stars and stellar evolution 2020-01-26T01:39:49.000
115 2021.2.00075.S 6 Measuring the background temperature of Orion Nebula Cluster disks We propose to mosaic the central 2.7' x 2.7' region of the Orion Nebula Cluster (ONC) with the ACA and TP array. These observations will probe extended molecular cloud structures in the region, which can influence the morphology of gaseous circumstellar disks observed with ALMA. In young, massive clusters like the ONC, we expect significant extended emission. We will target the CO(3-2) and HCO+(4-3) lines with a sensitivity of 0.2 K and spectral resolution of 0.25 km/s. These lines have been utilized in recent ALMA surveys of the ONC, which detected several-dozen gas disks not only in emission but also in absorption against the bright background cloud. Our short-baseline observations will complement the ALMA surveys and yield precise measurements of the cloud intensity towards known disks and proplyds in the region. With these measurements, we can extract cloud-corrected measurements of disk CO(3-2) and HCO+(4-3) emission for all of the disks detected in absorption with ALMA. By comparing the underlying physical/chemical properties of disks seen in emission vs. absorption, we will constrain the impact of the stellar cluster environment on circumstellar disk evolution. Disks around low-mass stars Disks and planet formation 2024-05-11T18:29:55.000
116 2012.1.00536.S 0 Physical Properties of Galaxies that Ionize the Universe Measuring the properties of low-luminosity galaxies near redshift 6 is central to understanding the reionization of the universe. Although hundreds of bright galaxies have now been identified at this era, their number density is too low to even maintain the ionization of the intergalactic gas, and lower luminosity galaxies detectable only via their line emission provide the closest relation between any high-redshift galaxy population and the sources that actually reionized the universe. Prior to ALMA, however, our knowledge of these important galaxies was limited to number counts and luminosity functions of hydrogen Lyman-alpha emission. The luminosity and line profile of this resonance line depend sensitively on the gas kinematics and dust content of the host galaxy, so Lyman-alpha observations alone provide little physical information about the galaxy properties. To establish the typical star formation rate, dynamical mass, and systemic velocity for the lowest luminosity galaxies yet detected at this important era, we request ALMA observations of their [CII] 158 um fine structure emission. Lyman Alpha Emitters/Blobs (LAE/LAB), Starburst galaxies Galaxy evolution 2015-07-02T13:41:03.000
117 2018.1.00299.S 470 Infall in the very early stages of high-mass star formation Although high-mass stars are the main source of kinematic and chemical enrichemnt in galaxies, their formation, in particular how they accrete their initial mass, is still poorly understood. To understand this, we need to measure the properties of high-mass star forming cores in very early stages of evolution. With this aim we performed an ALMA survey of high-mass clumps (500 - 5000 Msun) in early stage of evolution, identifying a large sample of massive pre-stellar core candidates. For one of the clumps, G331, addditional ALMA observations shows infall signatures to its most massive core, suggesting that is still accreting material. Our results suggest that the initial condition of high-mass stars are sub-virial cores of intermediate mass accreting from their environment. To determine if the process seen for G331 is ubiqutous, we propose to observe a combination of optically thick (HCO+, HNC) and thin (N2H+) tracers to meassure the total mass accretion (radial and/or along filaments) onto the 12 most massive cores detected in our survey. With these observation we will determine how high-mass stars acquire their mass and put constraints on high-mass star forming models. High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2020-08-06T22:41:19.000
118 2022.1.00534.S 0 Caught red handed: dusty quasars blowing out molecular gas The canonical picture of galaxy evolution invokes the injection of energy from supermassive black holes to reduce star formation efficiency in massive galaxies. However, the physical channels that allow energy and momentum released on sub-pc scales to affect gas on galactic scales are largely unconstrained. Theoretical models predict that radiation pressure on dust in the vicinity of the black hole is a major driving mechanism of galactic-scale outflows of cold gas. A recent study has found evidence for a direct link between quasar dust-reddening and molecular outflows. Here, we propose a survey of 10 reddened quasars at z=2.5 in CO(9-8) or CO(10-9) to investigate this relationship and explore the impact of radiative feedback on star-forming gas. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 2024-04-20T16:44:56.000
119 2023.A.00022.V 0 Exploration of High-Frequency SiO Masers with VLBI Newly available ALMA spectral line VLBI capabilities are poised to enable for the first time studies of the dynamic atmospheres of evolved stars at sub-mas resolution using high-frequency (>200 GHz) masers. However, a roadblock to planning such studies is a lack of basic knowledge of the properties of high-frequency masers on VLBI scales. To address this, the Event Horizon Telescope has approved exploratory observations of the 28SiO v=1, J=5-4 masers in a sample of 5 evolved stars in April 2024 that will be the first to probe high-frequency masers at <1 mas resolution. Here we propose to allow phased ALMA to join these observations in order to dramatically improve the ability to detect and characterize the masers on global baselines. Outcomes will include constraints on their brightness temperature and polarization properties on sub-mas scales. The current observations are proposed as a DDT program because of their exploratory and potentially high-risk nature. We aim at expedited publication to inform the design of future ALMA proposals focused on VLBI imaging of high-frequency masers, including those aimed at studies of evolved star atmospheres on scales down to ~0.002R_star. Asymptotic Giant Branch (AGB) stars Stars and stellar evolution 3000-01-01T00:00:00.000
120 2022.1.01365.S 0 Investigating possible protoplanetary disk instabilities induced by late infall While Class II protoplanetary disks have typically been thought of as isolated, scattered light and molecular line images are increasingly uncovering ``late infall'' signatures in the form of large-scale arm or tail-like structures connected to the disks. Simulations suggest that infalling material can give rise to disk instabilities, resulting in substructures such as spiral arms, vortices, and misalignments. These substructures, in turn, can influence the formation location and orbital properties of protoplanets. To investigate this potential link between infall and disk structural evolution, we propose high resolution continuum imaging and sensitive CO mapping of four Class II disks that exhibit evidence for disk perturbation by late infall. We will characterize the substructure morphology and examine their spatial association with larger-scale structures and possible variations with infalling mass. These detailed images will advance our understanding of the variety of circumstances under which planet formation takes place. Disks around low-mass stars Disks and planet formation 2024-08-24T19:07:51.000
121 2018.1.00771.S 119 Born with siblings: will I ever get my own space? A large fraction, if not the majority of stars form in multiple systems, yet the impact of the presence of close-by stars is usually neglected when studying how protoplanetary disks evolve and how planets form in them. One of the main reasons is the relative lack of extensive studies at high angular resolution of the properties of protoplanetary disks in multiple stellar systems. Our Cycle 4 survey of disks in the Taurus star-forming region at 0.1" resolution shows that mm-dust disk radii in 11 binary systems are among the smallest in the sample, and are as small as ~0.05-0.1 times the projected separation of the binary stars. These values are explainable by a tidal truncation event, but only if the eccentricity of the orbits is larger than 0.8. Very eccentric orbits would strongly impact the possibility of forming planets in these disks, as their radii would be just a few au. We propose here to obtain the still missing observation of CO in these disks around multiple stars in the Taurus region. We will determine the gas disk radii to confirm whether these disk are really small. Such a result would strongly impact our current understanding of planet formation around binaries. Disks around low-mass stars Disks and planet formation 2020-12-31T20:45:02.000
122 2013.1.00521.S 36 Isolating the starbursts in the most massive AGN hosts Using Spitzer, Herschel, SCUBA and LABOCA, we have obtained 12-band 3.6 to 870µm photometry of 71 radio galaxies covering 1 High-z Active Galactic Nuclei (AGN) Active galaxies 2016-10-05T21:44:25.000
123 2021.1.00590.S 28 No disk is an island: exploring possible late stage infall on disks in the Lupus clouds The current text-book description of how protoplanetary disks evolve assumes that, after the dispersion of the protostellar envelope, disks are isolated from the environment. In particular, no late infall of material from the molecular cloud onto the disk is expected in the Class II phase. Detecting such an infall is mainly hampered by the difficulties in carrying out observations at intermediate size of about 200-1000 au, ~1-5 arcsec, the scale between the leftover clouds and the disks. These sizes are too small for single dish telescopes and largely filtered out by interferometry, but accessibe with ALMA in its most compact configuration. However, there are indications from Herschel and scattered light images, CO maps, and theoretical predictions that infall onto disks can continue well into the Class II phase. Detecting such an infall will greatly change our view of star formation and disk evolution, and help to solve some of the current open questions in the field, such as the missing mass budget in planet formation. We propose ALMA ~1" Band 6 mosaics of 4 prototype disks and their environment in the Lupus cloud to reveal the structure and kinematics of the kilo-au environment. Low-mass star formation ISM and star formation 2023-05-25T07:11:54.000
124 2021.1.00675.S 43 New constraints on dark matter models with strongly lensed quasars Gravitationally lensed quasars have been established as a method to detect and quantify low-mass dark matter haloes at cosmological distances. The population of low-mass haloes is dependent on the mass of the dark matter particle, thus investigations of these lenses can give independent constraints on warm dark matter. From our successful pilot programme, we have established that with ALMA observations we can obtain a statistically significant sample of systems suitable for our analysis. By observing the prevalence of flux ratio anomalies in a sample 10 four-image lensed quasar systems, we will robustly test the cold dark matter paradigm in combination with our data in-hand. In a joint analysis with existing data, we expect to be able to exclude thermal relic masses of a warm dark matter particle up to 7 keV from 25 strong lens systems. This constraint will be more stringent than limits inferred with other methods (such as a 3.5 keV limit from the Lyman-alpha forest) and has the advantage that it does not assume a galaxy formation model, so will be an independent test of these other inferences. This proposal is a resubmission of an approved cycle 7 programme that was not completed. Gravitational lenses, Galaxy structure & evolution Cosmology 2023-08-22T20:10:55.000
125 2015.1.00030.S 2 Resolving the molecular gas within 100 pc of M87's supermassive black hole The proximity of M87 (3C 274), the archetypical giant elliptical radio galaxy at the centre of the Virgo galaxy cluster, presents a unique opportunity to investigate in detail the circumnuclear molecular gas revealed first by CO J=1-0 observations with the IRAM 30-m and more recently imaged for the first time with ALMA (this team's Cycle 1 data). The preliminary results from the ALMA data show that the molecular gas is unresolved and resides within 100~pc of the supermassive black hole (SMBH). With this Cycle 3 proposal we wish to obtain 0.12'' (~10~pc) imaging of the CO J=1-0 line to unambiguously resolve the molecular gas structures for the first time, allowing us to investigate the nature and origin of molecular gas that resides within the 3.1'' sphere of influence (SOI) of the SMBH in unprecedented detail. Such observations are only now possible with ALMA's long baseline capability. Galactic centres/nuclei Active galaxies 2018-09-20T00:00:00.000
126 2023.1.00991.S 0 A shocking exploration of phosphorus astrochemistry Phosphorus remains an an astrochemical enigma in dense star-forming regions: while the emission of PN and PO seems to be correlated with shocks, we still do not understand the underlying chemistry. With only two spatially resolved detections of P molecules to date, additional resolved observations are urgently needed to make progress. This program will target phosphrous molecules towards three nearby protostars with diverse shock environments and bright single-dish detections of PN, providing an ideal test bed for exploring the drivers of phosphorus astrochemistry. By covering PN and PO lines in ALMA Bands 3, 4, and 6 at 1" resolution, we will constrain the molecular column densities, excitation conditions, and emission origins. With this we can test, for the first time, what conditions are needed to eject P into the gas, and how the gas-phase P chemistry depends on a wide range of environmental factors. This program will help illuminate the journey of phosphorus, a key bioelement, in dense star-forming regions. And, with an improved understanding of their chemistry, gas-phase P molecules may become a valuable probe of the chemistry and physics of astrophysical shocks. Astrochemistry ISM and star formation 3000-01-01T00:00:00.000
127 2013.1.00262.S 13 ALLO: ALMA Lensed Line Observations We request 3.3 hours of band 6 time to observe [CI] (2-1) and CO (7-6) lines in 5 extremely lensed, but otherwise typical star-forming galaxies at redshifts z=2-3. These galaxies are part of our survey of [CII](158 micron) and [OI] (63 micron) lines with Herschel (the Herschel Extreme Lensing Line Observations 'HELLO'). The HELLO sample of normal galaxies forms an ideal complement to studies of dusty starbursts at z=2. Our propsed ALMA observations reach interesting limits of [CI](2-1)/FIR = 10^{-5.5} in 40 minutes (with overheads) per galaxy. In 2 cases, we will also detect the H2O 2(1,1)-2(0,2) line. Combined with the Herschel [CII] line measurements, the [CI] and CO lines will give a complete picture of the physical conditions, including density, far-ultraviolet flux, temperature, and pressures in atomic and molecular gas. With the [CII], [OI], [CI], and multiple CO lines we will have the total cooling budget and we can determine whether their ISM at z=2 is fundamentally different from the local universe. ALMA's spatial resolution will also allow a study of spatially resolved kinematics of these galaxies, among which some show outflows and some show cold rotation. Starbursts, star formation Active galaxies 2016-02-24T19:05:48.000
128 2015.1.01003.S 36 Proper Motions of Gas In the Immediate Vicinity of the Galactic Suppermassive Black Hole We propose to search for warm neutral gas at high projected velocities along the ling of sight, as an indicator of high possible motions across the line of sight. We propose to use SgrA* as the background source for measuring an absorption line profile, which are hopefully closer to the Galactic Center in high excited state. The high brightness temperature of SgrA* would compensate the low optical depth of faint features. This is a resubmission of our Cycle 1 proposal as it still may not get scheduled within Cycle 2. However, we note that with Cycle 3, we will have two main advantages: (1) Although officially a minimum of 36 telescopes will be available, we anticipate that even more will be operational. This means our raw sensitivity will be improved as compared to Cycle 1 and 2. (2) As we are using absorption against SgrA* to determine our angular resolution, we are not sensitive to which array configurations will be assigned to this project. However, very long baselines will be available in Cycle 3. This does help to suppress extended emission within the primary beam. Also absolute positions will be better defined, which will be important for proper motion studies. Galactic centres/nuclei Active galaxies 2017-10-14T00:00:00.000
129 2017.1.01411.T 105 The Final Evolution of Massive Stars toward Supernovae In the last few years, the new paradigm shift has been observed in the field of massive star evolution. Several optical observations of core-collapse supernovae (CC-SNe) have led to an emerging picture that the massive stars are much more dynamic in the last few years than widely accepted previously. However, the existence of the very dense circumstellar matter (CSM), created by intensive mass loss in the final few years, has been inferred mainly from the optical observations, interpretation of which includes highly model-dependent analysis of the radiation transfer effects and a combined effect from various alternative processes. We propose ToO observations of one CC-SN at Bands 3 and 6. The quick ToO at the mm wavelengths within ~10 days after the explosion is a unique and the most powerful diagnostics of the CSM environment in the vicinity of the SN progenitor. This relatively handy project (<3 hours) will bring us new and robust information on the yet-unclarified final evolution of massive stars, and may become a good test case to show the great capability of ALMA in the time domain astronomy. Supernovae (SN) ejecta Stars and stellar evolution 2019-06-26T17:20:13.000
130 2021.1.00473.S 95 A Chemistry Survey of Protoplanetary Disks in Binary Systems T Tauri disks display diverse chemical inventories. The reason for this diversity is unknown. In particular it is currently unclear what role, if any, initial chemical conditions play in setting the disk chemical trajectories. To address this, we propose to map out the chemistry of five pairs of nearby intermediate-separation binary T Tauri disks at 0.3" scale. Each binary system likely formed from a single cloud core with identical chemical initial conditions. By comparing chemical inventories within binaries and between binary pairs we will obtain first constraints on how important these initial conditions are. More particularly we will probe the disks using common tracers of disk CO masses, probes of C/N/O gas-phase ratios, and deuterium fractionation probes, and in a number of organic molecules of different complexity. Together these observations will enable unique constraints on whether disk chemistry mainly depends on the chemical starting point, or whether the chemistry is completely reset and only depends on the details of star+disk system. Which scenario correctly describes reality will have a large impact on how we model the chemical evolution in planet forming disks. Disks around low-mass stars Disks and planet formation 2023-08-09T18:05:16.000
131 2023.1.01182.S 0 Unveiling the physics controlling cloud and star formation in extragalactic Central Molecular Zones (eCMZs) Gas-rich galaxy centers like our own Central Molecular Zone (CMZ) are extreme environments for cloud and star formation where many formation promoting or inhibiting forces acting locally or on larger scales compete. We propose ~20pc resolution, sensitive (rms~0.5K per 2.5 km/s) CO(2-1) imaging of a representative, unbiased set of 15 nearby well-studied extragalactic CMZs to provide the first robust statistical assessment of CMZ molecular cloud (complex) properties (mass, line width, size, pressure, timescales etc.) and correlate these with global CMZ and galaxy properties to determine whether local processes (i.e. stellar feedback) or large-scale environment control their star formation activity and answer if the unexpected properties of our own CMZ are unusual or common. Further we will quantify if and how central AGN and starbursts alter CMZ cloud properties, and thus regulate subsequent star formation. This comprehensive study will provide the urgently needed data to distinguish between theories for CMZ star formation that either argue for a highly time-variable evolution caused by local processes or a more steady-state evolution regulated by the large-scale environment. Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties Active galaxies 2025-01-11T18:19:49.000
132 2021.2.00096.S 9 Investigating a bottleneck in the phosporous cycle, and a search for active volcanism on Venus Venus hosts an extremely dense, dry, CO2 and sulphur-rich atmosphere, believed to be influenced by volcanic outgassing, yet evidence for present-day (active) volcanism on Venus is scarce. We propose to use the ACA to perform two related studies of Venus's atmosphere, to address its origin, evolution, composition and habitability. Our first objective is to observe the chloride salts NaCl and KCl as direct probes of active volcanic outgassing. Our second objective is to detect the PO and PS molecules to quantify the phosphorous budget in the upper atmosphere, thereby elucidating possible chemical pathways to phosphine (PH3) - a theorized biomarker. Solar system - Planetary atmospheres Solar system 2023-08-16T22:55:37.000
133 2016.1.01468.S 161 The nitrogen isotopic ratio in interstellar ices To which extent planetary systems preserve their interstellar heritage is a central question in astrochemistry. In this context, knowledge on the formation of the solar system brings invaluable insights to our understanding of the formation of planetary systems in general. Yet, the origin of the volatiles in the solar system is not fully known, especially for nitrogen. The isotopic ratio of nitrogen displays unexplained large variations in the Solar system, and one salient problem is that the isotopic ratio of nitrogen in comets is remarkably homogeneous but twice smaller than that on Earth and thrice smaller than that in the Sun. Moreover, these sharp discrepancies cast doubts on our understanding of the formation of comets and their use as tracers of the early Solar system. One solution could be the existence of a secondary reservoir of nitrogen in prestellar ices, which would have been trapped in comets. If this is the case, the isotopic ratio should be different from that of the bulk in gas phase. We propose to use ALMA to accurately measure the isotopic ratio of nitrogen in prestellar volatiles desorbed from ices towards two protostars. Low-mass star formation, Astrochemistry ISM and star formation 2018-05-27T10:19:10.000
134 2023.1.01393.S 0 Water deuteration in solar-type protostars: an effect of environment? Water deuterium fractionation is commonly used as a tool to characterize the evolution of water from the earliest stages of the star formation process until its incorporation into planets. So far, the HDO/H2O ratio has been determined towards seven Class 0 protostars. The three isolated sources show an HDO/H2O ratio higher than the clustered sources and it is interpreted as an effect of different initial conditions in the two types of environments. Most recently, the HDO/H2O ratio was investigated towards two Class I objects, which belong to different molecular clouds, and their HDO/H2O ratios were found to be similar to the isolated Class 0 sources. The reason for that would be that they come from regions with a lower source density than the studied clustered Class 0 protostars. The sample is however too limited for firm conclusions. We propose to determine the HDO/H2O ratios in 6 additional protostars with different environments and evolutionary stages to confirm that the environment is the main reason for the different HDO/H2O ratios and that water deuterium fractionation ratio can actually be used as a tracer of the initial conditions from which the protostar forms. Astrochemistry ISM and star formation 2025-01-04T23:23:58.000
135 2021.1.00723.S 46 Probing the physical condirtion of the extremely high density prestellar core G208.68-19.20-N2 A compact (r~ 220 au) and extremely dense (> 10^9 cm^-3) object embedded in a filamentary structure has been unveiled in the prestellar core, G208.68-19.20-N2 (G208-N2), in Orion Molecular Cloud 3. This compact object referred as a "nucleus" is likely to be in the evolutionary stage immediately before the onset of star formation. In order to study the physical conditions of the nucleus and filament, we plan to constrain the dust temperature using the continuum emission observed with the high frequency bands of ALMA. If the dust temperature is lower than 10 K, the peak of its spectral energy distribution appears in the submillimeter band that can be accessible with the high frequency bands of ALMA. W also plan to study the gas kinematics, such as gas flow, turbulent decay, and rotation in the vicinity of the nucleus using the ortho-H2D+ line emission at 372 GHz. The light deuterium-bearing species like H2D+ might be the unique probe for dense and cold region where most of the molecular species including N2D+ are heavily depleted onto the dust. Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2023-09-30T13:54:23.000
136 2013.1.01157.S 0 IRAS 15398-3359: Very Low Mass Class 0 Protostar? In star-formation studies, an important target is to understand when and how the rotationally supported disk is formed around the protostar. In order to address this question, we recently conducted the ALMA observations of the CCH (N=4-3) and H2CO (515-414 etc.) lines in Band 7 toward the low-mass Class 0 protostar IRAS 15398-3359 at a resolution of 0."5. We detected a beautiful outflow feature as well as a flattened envelope around the protostar. From the analysis of the outflow structure, the inclination angle of the envelope is estimated to be 10 degree (i.e. almost edge-on). Then, the velocity structure of the envelope is analyzed, and the mass of the protostar is roughly estimated to be as low as 0.02 Msun. Furthermore, the H2CO emission shows a sign of a Keplerian disk. These results will be an important clue to understanding the initial stage of disk formation processes, if confirmed. We here propose to observe the CCH (N=3-2) and H2CO (515-414 etc.) lines in the Band 6 and Band 7 at the resolution of 0."23 and 0."16, respectively. This observation will provide us with a deep insight into the initial stage of disk formation in Class 0 protostars. Low-mass star formation, Astrochemistry ISM and star formation 2016-11-09T18:28:08.000
137 2021.A.00008.S 11 [CII] confirmation of a z = 13.27 galaxy We propose to robustly confirm/reject the existence of a star-forming galaxy at z=13.27. Recently, a tentative 3.8 sigma detection of [OIII] at 88 microns was reported for this target, dubbed HD1 (Harikane+2021). If confirmed, it would make HD1 the highest-z galaxy known to date. The existence of such a mature galaxy only 300 Myr after the Big Bang has major implications for galaxy formation theories, and sets the stage for future JWST studies. However, a 3.8 sigma single-line detection is both weak and not spectroscopically secure, and may instead be caused by random noise features or CO emission from a low-z foreground galaxy. The community thus deserves a rapid, definitive test to determine which scenario is true; we therefore request DDT observations totalling 7.2 hours, which will robustly detect, if present, the bright [CII] 158 micron fine-structure line (redshifted to Band 4). A non-detection would instead, most likely, imply that HD1 is a z~3.9 passive galaxy, challenging our understanding of quenching when the Universe only was 1.6 Gyr old. This low-risk/high-gain DDT proposal will thus have major implications for studies of galaxy formation and evolution. Lyman Break Galaxies (LBG) Galaxy evolution 2022-09-21T15:17:07.000
138 2022.1.00687.S 0 Search for Molecular Gas Nebulae surrounding Galaxy Groups The circumgalactic medium (CGM) is the venue where traces of outflowing material expelled from galaxies and inflows of gas from dark matter filaments are found. To understand how galaxies evolve, it becomes crucial to constrain the physical properties of the CGM across all phases (molecular, neutral and ionized). We propose to observe with ACA the extended molecular gas emission associated with two galaxy groups at redshift z ~ 0.5. There is already a wealth of archival data available for both these targets from MUSE, ALMA and HST. The detection would be the first of its kind around 'normal' galaxies at this redshift and allow us to link the molecular, neutral and ionized gas phases with the SFR, metallicity and stellar mass of galaxies in the group. Merging and interacting galaxies, Outflows, jets, feedback Galaxy evolution 2024-09-11T12:34:17.000
139 2019.1.00110.S 9 Dynamical Properties of Dusty Star-Forming Galaxies in the Peak Epoch of Star Formation Dusty star-forming galaxies (DSFGs) at high redshift are thought to be predominantly highly dissipative mergers of gas-rich galaxies representing extreme, short-lived starbursts. This picture is supported by studies of gas dynamics, but unfortunately, the resolution of such investigations typically remained limited to 3-4 kpc in the past, which is barely adequate to resolve the galaxies. Using the advanced capabilities of ALMA and the magnifying effect provided by gravitational lensing, we here propose to study the [CII] gas dynamics in 4 strongly-lensed Herschel-selected DSFGs in Einstein Ring configurations, covering the peak epoch of galaxy formation (z=2-6) down to 100-500pc resolution. Enabled by uv plane lens modeling (pioneered by our group) and dynamical models, we will carry out a comprehensive investigation of the occurance rate of major mergers vs. disks in our sample, measure dynamical masses and gas fractions, and constrain the physical properties of individual gas clumps down to unprecedented physical scales at high redshift. The proposed lens configurations will also be ideal to study dark matter halo substructure - allowing our analysis to unfold its full potential. Starburst galaxies, Gravitational lenses Active galaxies 2022-07-08T20:45:20.000
140 2018.1.00579.T 21 Radio Polarimetry of GRB Afterglows Gamma-Ray Bursts (GRBs) are currently being exploited as probes of the first generation of stars. Therefore, ongoing research aimed at understanding GRB progenitor stars represents one of the most pressing inquiries in modern astrophysics. Undoubtedly one of the most critical measurements is the Faraday depolarization along with spectrum evolution caused by non-energized electron, which requires the revision of the standard mass of the progenitor star. As we demonstrated by making the first radio polarization measurement with our Cycle 5 program, linear polarizations in Band3 with the high sensitivity are essential for discovering these non-energized electrons, because the Faraday depolarization caused by the non-energized electrons suppress the linear polarization degree at a frequency of 100-1000 GHz. In this program, we intend to conduct linear polarlimetry at the millimeter wavelength (Band3) together with simultaneous ACA photometry (Band7). The intensive studies of non-energized electron in a number of afterglows will make a revolutionary change in the GRB progenitors, because diversity of GRB prompt emissions and afterglows are likely linking with type of progenitor stars. Lyman Break Galaxies (LBG) Galaxy evolution 2020-01-27T03:14:52.000
141 2016.1.00184.S 17 High-Resolution [Cii] Imaging of the Most Luminous Galaxy The WISE mission has identified a rare population of high-redshift, hyper-luminous infrared galaxies, all with bolometric luminosities above 10^13 L_Sun, and many exceeding 10^14 L_Sun. Characterized by their extremely red mid-IR colors and very hot dust temperatures, these hot, dust obscured galaxies (Hot DOGs) likely probe a key stage in the galaxy evolution paradigm. During Cycle-2 we obtained band 7 observations of the highest redshift Hot DOG W2246-0526 at z=4.601, which has been shown to be the most luminous unlensed galaxy or quasar known. These observations showed a rich reservoir of ionized gas in this galaxy through a highly significant detection of the [CII] emission line. The very bright [CII] flux observed for W2246-0526 enables the chance to obtain with ALMA an unprecedentedly detailed distribution of the gas in such a high-z, unlensed galaxy. Here we request 0.06" resolution observations of the [CII] emission line and study in detail the host galaxy of this remarkable object. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 2018-10-09T07:31:37.000
142 2017.1.01334.S 38 Non accreting proto-planetary discs: a new evolutionary class? The aim of this proposal is to observe three unusual protoplanetary discs in the young (2-3 Myr), nearby (~160 pc) Chameleon I region: they have a large IR excess but do not show any detectable accretion, contrary to the conventional picture of disc evolution in which accretion and IR excess disappear at the same time as the disc is dissipated. The targets have a measured sub-mm continuum but no gas detection in an ALMA Cycle 2 survey, opening the question whether they are gas depleted and transitioning to the discless phase. We propose a sensitive search of gas emission lines (CO isotopologues) to establish their gas content, allowing us to assess whether they are young, optically thick debris discs (i.e., little or no gas left over), gas rich discs with inefficient angular momentum transport, or low mass discs that are surprisingly resilient to photo-evaporation. In any case, we would gain insight on a class of object that has received little attention up to now. ALMA is the only instrument sensitive enough to perform such a search. Disks around low-mass stars Disks and planet formation 2019-02-22T04:43:16.000
143 2012.1.00621.S 8 Proper Motions of Gas in the Immediate Vicinity of the Galactic Supermassive Black Hole We propose to search for neutral gas at high projected velocities along the line of sight, as an indicator of high possible motions across the line of sight. We propose to use SgrA* as the background source for measuring an absorption line profile. This utilizes the high brightness temperature of SgrA* to compensate for the low optical depth of faint features. By using high excitation lines in the submillimeter bands (HCN(J=4-3),HCO+(J=4-3),CS(J=7-6),H13CN(J=4-3),HC15N(J=4-3)), we will sample material which are hopefully closer to the Galactic Center. This will also minimize confusion from the lower excitation material, which will not populate the higher energy levels of the molecules. We propose to utilize SgrA* to provide an effective “delta-function pencil beam”. This improves upon the normal synthesized beam provided by the interferometer. With the multi-epoch measurements, our goals are: (1) detect and measure the line profile of high excitation transitions in absorption against SgrA*, (2) measure the time variation of the proper motions of the clouds in front of SgrA*, (3) measure the chemical species that survive immediately surrounding SgrA*. Galactic centres/nuclei Active galaxies 2017-10-14T00:00:00.000
144 2015.1.00513.S 4 Anatomy of a Fried Egg IRAS 17163-3907 was recently identified %by Lagadec et al (2011) as the closest and brightest Yellow Hypergiant. Infrared imaging of the dust emission implies a very intense mass-loss, with 2-4~Msun of gas ejected in the last 500 years. This led to the formation of at least two concentric dusty shells. This makes IRAS~17163 a unique object for the study of the mass-loss process in a spectacular short-lived phase towards the end of the life of a massive star, before it explodes as a supernova. Our Cycle 2 proposal to observe it was accepted, but only compact array observations were taken, enabling us to discover the formation of a swept-up ISM bubble around this Yellow Hypergiant.We propose to complete our observations and study these shells in CO J=2-1 emission with ALMA, to probe the kinematics and morphology of the gas in this massive stellar envelope. This will enable us to measure the amount of gas ejected, the time scale of the ejection and check whether the dust and gas ejection are coupled. These measurements are the key for understanding the physics of the intense mass loss during this short-lived, and thus rare, phase of stellar evolution. Hypergiants, Evolved stars - Shaping/physical structure Stars and stellar evolution 2017-01-29T10:44:42.000
145 2013.1.00645.S 3 Resolving the narrow Kuiper belt analog around epsilon Eridani The nearby star epsilon Eridani hosts the closest known analog to our Kuiper belt and is the only K dwarf among the ``Fab Four'' prototype debris disk systems first discovered with IRAS. Sub-mm/mm imaging with SCUBA and MAMBO have revealed the presence of a belt of large grains at a radius of ~ 70 AU which is constrained to have a width <~ 6 AU, implying a Kuiper belt analog which is at least as narrow as the one in Fomalhaut recently studied with ALMA and our own classical Kuiper belt.We will obtain ALMA continuum imaging at 230 GHz (1.3mm) in order to provide the first high resolution and high signal to noise sub-mm data for part of the dust ring of the epsilon Eridani system. The proximity of epsilon Eridani (3.2 pc) makes this the best debris disk to constrain the narrowness of its planetesimal belt. The data will resolve the width of the ring for the first time, setting constraints on the mechanisms which maintain such narrow rings, such as planetesimal shepherding by planets. Additionally it may identify the presence of clumps suggested by previous single-dish images interpreted as planetesimals trapped in resonance with an unseen planet. Debris disks Disks and planet formation 2016-07-31T08:16:47.000
146 2018.1.00037.S 36 The nature of a rotating dense gaseous torus in NGC 1068 We propose the longest-baseline ALMA band 6 observation of the nucleus of the prototypical type-2 AGN, NGC 1068. Our Cycle-4 data of HCN J=3-2 and HCO+ J=3-2 lines have revealed clearly, for the first time, the long-sought-after rotation of dense molecular gas along the putative torus direction around a central mass-accreting supermassive black hole (SMBH). However, we have also found surprising torus properties, when compared to a classical torus picture; (1) the torus dense molecular emission is highly asymmetric, and (2) rotation at a few pc scale is far from Keplerian motion. With the proposed 0.02" (~1pc) resolution data of HCN and HCO+ J=3-2 lines, as well as the isotopologue H13CN J=3-2 line, we will (1) investigate the origin of the asymmetric dense molecular emission, (2) derive mass distribution of the torus from the optically-thin isotopologue line, and (3) search for mass inflow signatures and Keplerian velocity increase toward the central SMBH. This is a crucial step toward understanding the dusty gaseous torus in an AGN. Since our observing strategy is based on the clearly detected emission lines in our ALMA Cycle-4 data, our feasibility estimate is highly secure. Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei Active galaxies 2020-11-07T00:24:49.000
147 2013.1.00446.S 3 Characterizing the Atmosphere and Surface of Pluto We will use the unmatched sensitivity of ALMA to make significant advances in understanding of Pluto's atmosphere and surface. The atmosphere exhibits sublimation-condensation exchanges with surface ices and active photochemisty, but is poorly characterized. Our goals: * Atmospheric CO detection, vastly improving determination of its abundance, with implications for the nature of surface-atmosphere interaction and constraining atmospheric temperature * Sensitive search for photochemically produced nitriles like HCN which play major roles in the atmospheric budget * High SNR individual brightness temperature measurements of Pluto and Charon, and determination of their submm surface emissivities Our observations are designed to measure important aspects of Pluto and Charon that only ALMA can provide. The New Horizons spacecraft will fly through the Pluto system in July 2015. Our measurements are both distinct from (CO and nitrile abundances) and complementary to (upper atmospheric structure; relation to hazes; surface Tb and emissivity properties) New Horizons observations. They will serve as benchmarks for the study of dwarf planets and other Kuiper Belt objects. Solar system - Planetary atmospheres, Solar system - Trans-Neptunian Objects (TNOs) Solar system 2016-07-23T12:00:26.000
148 2021.1.00348.S 0 Measuring the magnetic field through CN Zeeman effect in G31.41+0.31 This proposal aims to estimate the magnetic field strength toward G31.41+0.31 (G31) by using the Zeeman splitting of CN. G31 is one of the clearest examples of magnetically regulated high-mass star formation. Taking advantage of the simple magnetic field morphology, which has been successfully modelled with an almost pure 3-D poloidal (hour-glass) field, we propose to observe several transitions of CN(1-0) at 3mm and 1.2 arcsec resolution to estimate the magnetic field strength along the line of sight. Since CN is a paramagnetic molecule, it shows a strong Zeeman effect under the influence of the magnetic field. Previous ALMA 1.2 arcsec observations of G31 have clearly detected CN in absorption with all the hyperfine transitions well resolved and unblended, and SMA 1 arcsec and ALMA 0.2 arcsec dust polarization observations have allowed to roughly estimate the magnetic field strength by using the Davis-Chandrasekhar-Fermi method. Zeeman splitting will allow us to obtain a precise measurement of the magnetic field strength along the line of sight to better constrain the mass-to-flux ratio and to directly confirm the importance of the magnetic field in the dynamics of the G31 core. High-mass star formation ISM and star formation 2024-06-14T19:50:54.000
149 2018.1.00378.S 16 ALMA CO Survey of the Brightest X-Ray Supernova Remnants in the Nearby Spiral Galaxy M33 Investigating the interstellar gas associated with supernova remnants (SNRs) is important in understanding the origins of both synchrotron X-rays and thermal X-rays, via magnetic field amplification and ionization of neutral gas, respectively. Most recently, we revealed the giant molecular clouds (GMC) possibly interacting with the 8 X-ray brightest SNRs in the spiral galaxy M33 using the CO data of the IRAM 30-m single dish telescope. However, we could not resolve molecular clouds along the SNR shells due to the coarse angular resolution of the IRAM CO data of ~12 arcsec (~50 pc resolution at the distance of M33). To clarify the cloud association and physical properties of molecular clouds (mass and density), we need further CO observations with finer angular resolution of at least an arcsecond. Here, we propose CO 2-1 observations toward the GMCs in the M33 SNRs using ALMA with an angular resolution of ~0.5 arcsec (~2 pc resolution at the distance of M33). ALMA's unprecedented sensitivity and spatial resolution will allow us to study the shock-cloud interaction in the M33 SNRs for the first time. Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2019-12-25T16:06:12.000
150 2013.1.01155.S 9 ALMA Observations of the Most Luminous Young Stellar Object in the Large Magellanic Cloud We propose to probe the dense circumstellar environment of the most luminous young stellar object (YSO) in the Large Magellanic Cloud (LMC) and among the most luminous forming stars detected in any galaxy. Our recent Herschel Space Observatory key program HERITAGE performed a uniform far-IR survey of the LMC, and using these observations we identifed thousands of YSOs in the LMC, including the proposed target, which we have determined to have a total luminosity of approximately 10^6 L_sun, making it the most luminous forming star in the LMC. To understand how stars with such tremendous masses form, we must observe them during their short-lived formation stages. We propose band 3 ALMA observations of this massive YSO of CO, 13CO, C18O, HCO+, HCN, and 1 mm continuum to 1) determine its multiplicity, 2) accurately determine the physical properties of the star-forming clump/core(s) (masses, densities, line widths, etc.), and 3) measure the feedback from the massive star into the surrounding medium. We will use 12CO to trace the high velocity, low density outflow, while C18O, 13CO, HCN, and HCO+ will be used to trace the low-velocity, high-density gas perturbed by the wind. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2016-11-27T06:16:52.000
151 2017.1.00297.S 476 An ALMA-ACA Survey of CO(2-1) in PG QSOs We propose ALMA ACA-only observations for a sample of 24 southern z<0.1 PG QSOs to characterize their gas contents and kinematics via CO(2-1). These powerful QSOs are well characterized across the EM spectrum, yet our knowledge of their gas reserviors, which may directly relate to their AGN power, remains biased/incomplete. The all-sky nature of this basic survey is naturally suited to undersubscribed ACA, and will provide a uniform characterization of the CO properties of this important sample, unlocking the potential for future follow-up. Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2018-11-15T18:12:56.000
152 2012.1.00031.S 0 A Survey of Dense Cores in Chamaeleon I Recent interferometric surveys of "starless" cores haved found that 1) 5-20% of these objects actually harbor low-luminosity star-forming objects and 2) that none of the truly starless cores have any detectable substructure or evidence for fragmentation. However, these surveys were intentionally biased and suffer from small sample sizes. Here we propose to carry out a 3mm continuum and CO (1-0) survey of the Chamaeleon I molecular cloud, targeting all 60 "starless" cores and all 13 positively identified young stellar objects. This survey will enable the first accurate, uniform, and high resolution census of dense cores in a molecular cloud, classifying them as being starless or protostellar. The properties of these cores and the relative numbers in each phase will allow us to study the time evolution of the star formation process and accretion timescales. Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2015-02-25T16:53:21.000
153 2011.0.00767.S 0 The [CII] Line Study of a Star-forming Galaxy in the Epoch of Cosmic Reionization Detecting galaxies from the local to the highest redshift Universe, including the epoch of cosmic reionization at z > 6, and characterizing their star formation activity and physical properties are obviously a key issue to understand the formation and evolution of galaxies as well as disentangle the relationship between the diverse populations of galaxies. While star formation and dynamics of low-z galaxies have been well studied using the CO lines as a tracer, those of high-z galaxies have not due to its faintness.Meanwhile, the ionized carbon 158 micron [CII]line can be a powerful alternative to detect high-z galaxies, because it is the strongest cooling line of ISM in galaxies and observable at submm/mm when redshifted to z >6. The ALMA can detect high-z [CII]line only in a few hours and resolve galaxies in this line emission on a few kpc scales, enabling to probe obscured star formation and constrain the sizes, the dynamical masses and ISM in early star-forming galaxies at the epoch of reionization for the first time.Here, we propose the ALMA [CII]line observation of a star-forming galaxy at z >6. We particularly propose to target a z = 6.96 galaxy IOK-1, because it is one of the spectroscopically confirmed highest-class redshift objects in the epoch of reionization and we have a lot of information about this galaxy that can be compared with the ALMA observation. Using IOK-1 as a probe, we will (1) reveal the relation between high-z and local star-forming galaxies, (2) estimate obscured SFR at z~7, (3) investigate the morphology, dynamics and physical properties of a z~7 galaxy, (4) to constrain the physical states of ISM in a z~7 galaxy. Starburst galaxies, Galaxy structure & evolution Active galaxies 2014-02-27T15:42:00.000
154 2017.1.00394.S 19 [CII] and Continuum High Resolution map of a Quasar Host formed through a wet merger of galaxies at z=4.4. The z=4.4 quasar BRI 1335-0417 provides the unique opportunity to study the ISM of a quasar host galaxy in unprecedented detail. Our high-quality, 0.2" (~1kpc) resolution imaging of the CO(2-1) emission (using the VLA in an unparalleled effort, >50 hour integration) demonstrates that the molecular gas in the host galaxy is distributed over 10 kpc, and is dynamically complex, hinting at an ongoing gas-rich ('wet') merger. This is the highest-quality/resolution CO dataset available for any unlensed high-redshift source accessible with ALMA. We here propose to complement this dataset with spatially-matched [CII] (and underlying continuum) emission. This is possible given the recent detection of strong [CII] emission in the source using APEX. In only 1.2 hours of on-source integration with ALMA, we will map the [CII] and underlying continuum at kpc resolution and unprecedented sensitivity. Together with the CO imaging, this will provide the first beam-matched dataset of a high-z galaxy to study the interplay of star formation (as traced through [CII] and FIR emission), central black hole accretion (through unresolved FIR emission) and the molecular gas reservoir (CO). Starburst galaxies, High-z Active Galactic Nuclei (AGN) Active galaxies 2019-01-31T02:51:35.000
155 2015.1.00241.S 16 Star formation in the 1000 km/s shock of Stephan's Quintet Stephan's Quintet galaxy group is one of these must-do targets revealing surprises each time being looked at by a new instrument. The most striking feature is a giant intergalactic shock created by a 1000km/s galaxy collision, with very low star formation despite an amount of warm molecular hydrogen comparable to the molecular content of the Milky Way. Our Herschel [CII] and IRAM 30m CO(1-0) measurements show that the gas kinematics are complex (FWHM=1000 km/s) on large scales (10 kpc). PdBI CO(1-0) observations reveal molecular complexes of 2-5kpc in size, but with star formation efficiencies varying by a factor of 20. Why? We propose to map the CO(2-1) and SiO(2-1) emission at spatial resolution of 0.2"=80pc, comparable to the size of Giant Molecular Clouds (GMCs), to measure the gas turbulence on scales where gravitationally bound clouds may form, and identify whether the star-forming regions in the shock are the sites of dissipation of kinetic energy through molecular shocks. These ALMA observations will characterize the role of the energy cascade, from bulk motions to turbulent motions on GMC scales, on the regulation of star formation in extremely turbulent environments. Merging and interacting galaxies, Galaxy groups and clusters Galaxy evolution 2018-01-17T17:08:55.000
156 2018.1.01291.S 54 Searching for the Water Snow Line in Circumstellar Disks of Eruptive Stars The location of the water snow line in protoplanetary disks is key to various planetary formation processes including the transport of water to the surfaces of terrestrial planets. While the presence of this snow line has long been predicted, its identification in resolved imaging has been complicated by its temperature dependent location which typically lies within 1-5 au for Solar mass stars. During an ALMA campaign to characterize the disks and outflows surrounding accretion-enhanced outbursting FUor protostars, we obtained the first resolved images exhibiting signatures of the water snow line in a protoplanetary disk. The presence of the snow line in an outbursting protostar, whose increase in luminosity has caused the location of the snow line to move from ~3 au to 43 au, indicates that the radial position of water ice may be more variable throughout protostellar evolution than previously believed. We propose ALMA band-6 continuum observations at 0.025'' resolution (10 au) to identify the location of water snow lines in two more FUor disks, solidifying the prevalence of such a feature and confirming its variable position during protostellar evolution and planet formation. Disks around low-mass stars, Exo-planets Disks and planet formation 2020-12-24T20:50:55.000
157 2016.1.01141.S 101 Formation and Evolutionary Processes of Low-mass YSOs in Lupus The Lupus star forming regions are among the nearest, low-mass star-forming complexes, and together they host objects spanning evolutionary stages from pre-stellar to pre-MS. By studying members of the same region, environmental factors can be considered sufficiently comparable. We plan to observe 8 objects from prestellar to protostellar phases. These sources are chosen from our group's multi-wavelength source catalog and Band 7 observations in Cycle 2. Our molecular line selection in Band 6 will probe the dense cores (N2D+, C18O, continuum) and molecular outflows (CO, SiO). We aim to reveal formation and evolution processes of cores -- composed of envelopes and circumstellar disks -- through their morphology, velocity structure, density structure, and angular momentum distribution. Complementarily, the outflow opening angles and dynamical timescales constrain mass accretion mechanisms and disk formation. Our selection of sources within regions at the same environment, with identical observing strategy, allows for consistent comparison of sources within our sample and across evolutionary stages. Outflows, jets and ionized winds, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2018-05-22T16:20:36.000
158 2017.1.01340.S 0 A pilot search for new FIR absorbers at z~1 on three gravitaionally lensed SPT sources Observations of absorption lines from the foreground intervening gas in the spectra of background bright sources have allowed direct constraints on gas abundances. This technique has been widely used in UV/optical/NIR for over a decade, however such studies in FIR/submillimeter at cosmological distances (z>0.1) are restricted to only three gravitationally lensed systems, and new absorbers have not been found for over a decade. Our 2500 degree-square SPT survey has uncovered over 100 bright submillimeter galaxies, the majority of which are strong galaxy-galaxy lensed so ideal for searches of new FIR absorbers. In this pilot study we propose to target prominent absorption lines in CI and CO, on three lensing systems at z~1. The foreground lens galaxies have confirmed spectroscopic redshifts and star-forming activites based on their optical spectra. We aim to directly measure the abundances of CI and CO in the line-of-sight and compare the results to galactic molecular clouds as well as other FIR absorbers. Discovery of any absorber will provide a major step forward in the studies of FIR absorption, and lead to a full search in our SPT sample. Galaxy structure & evolution Galaxy evolution 2019-11-22T16:26:32.000
159 2021.1.00657.T 6 Revealing the Structure and Magnetization of GRB Jets with ALMA Polarization Observations Polarization measurements of the afterglows of long-duration gamma-ray bursts (GRBs) probe the structure and magnetization of their relativistic jets, revealing the nature of their elusive central engine. While reverse shock (RS) polarization probes magnetic field structure in the jet, polarized forward shock (FS) emission is sensitive to the jet angular structure and viewing geometry. The ideal window to search for these polarization signatures is in ALMA Band 3, where both components are observable longer than at higher frequencies, while still being unaffected by interstellar scintillation and depolarization from synchrotron self-absorption. Pioneering ALMA Cycle 6 full Stokes observations of GRB 190114C uncovered polarized RS emission at 97 GHz (the first detection of radio/mm polarization in a GRB), yielding direct measurements of the angular coherence scale and magnetic field geometry in the jet. We now propose to triple the sample with linear polarimetry of up to two new GRB afterglows to determine whether the low level of polarization (1%) seen in GRB 190114C is common, aiming to constrain the central engine and jet acceleration mechanisms in these relativistic transients. Transients Stars and stellar evolution 2024-02-07T16:11:14.000
160 2015.1.00412.S 146 Chemistry in the Brightest Luminous-Infrared Merger We propose to fill a large gap in extragalactic spectral surveys by observing NGC 3256, the most luminous galaxy within z=0.01. This galaxy is the brightest on the sky among the luminous infrared galaxies (LIRGs) powered by merger-induced galaxy-wide starburst. This class, whose energy source is known to be starburst (not an AGN), is the majority of the luminous LIRGs (11.5 ~ < log L(IR) < 12). Also, they are ~10 times more luminous than NGC 253 and M82. Yet disproportionally little attention has been paid for its astrochemical properties. We will observe key molecular tracers in multiple transitions in Bands 3 and 6, and compare the derived chemical abundances to those in Arp 220, a ULIRG having very compact energy source(s), NGC 253, a local starburst, and the Seyfert nucleus of NGC 1068, as well as other sources with spectral scans. Principal component analysis will reveal the effects of merger and high-luminosity in the chemical composition. Galaxy chemistry, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Galaxy evolution 2018-02-16T00:00:00.000
161 2015.1.00723.S 16 Dissecting the colossi: confronting recent theory with two multi-merging HyLIRGs Amongst sub-mm galaxies (SMGs), only a handful are hyperluminous infrared galaxies (HyLIRGs; > 10^13 solar luminosities in the IR). For a standard IMF, a HyLIRG hosts a staggering star formation rate of > 1000 solar masses per year for a very short (Myrs) period. Exploiting the relationship between CO luminosity and line width determined for fainter starbursts, we have identified and removed lensed sources from the widest {\it Herschel} extragalactic imaging surveys to yield a sample of rare, intrinsically luminous galaxies. Panchromatic observations of the two best HyLIRG candidates led to the discovery of at least two components on each system, each of them being an excepcionally bright, gas-rich HyLIRG. We propose to observe our two excepcionally bright merging HyLIRGs in CO, CI and H2O at high resolution (0.20'') with the aim of studying in detail their kinematic, the morphology of their gas and dust, and explore the presence of molecular outflows. These observations will be compared with the most recent hydrodynamic simulations of isolated and merging galaxies, providing important clues of the evolution of these unique systems. Starburst galaxies, Sub-mm Galaxies (SMG) Active galaxies 2018-03-13T14:45:45.000
162 2013.1.00989.S 10 Probing the inner-most region of the relativistic jet in extreme TeV blazars We propose to observe continuum spectrum of five extreme TeV blazars, which are unique probe to study enigmatic extragalactic background light (EBL), for the first time in mm/sub-mm regimes at two frequencies. The goal of this study is to investigate whether their relativistic jets are optically thin at mm wavelengths. Our preparatory study with ALMA shows optically thin mm-spectrum in most normal blazars, contrary to the most accepted "one-zone SED model" predicting their relativistic jets are optically thick in mm regime. In addition, our study with VLBI does not favor it also for extreme TeV blazars. If mm emission is optically thin in also extreme TeV blazars, it requires alternative models such as the structured jet model where both of high-energy emission and mm emission can come from the jet base. It will not only give a new picture of jets in blazars, but also affect studies on EBL based on SED models. These sources are faint for other radio interferometers. Furthermore, sequential observation in two bands is necessary for this proposal, since blazars are usually variable within days-weeks at mm/sub-mm wavelengths. Only ALMA cycle-2 can perform proposed observations. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2016-08-06T14:26:45.000
163 2015.1.01323.S 28 Characterizing the possibilities of planet formation in the hostile enviroment of Carina Proplyds, a singular class of young stellar object (YSO), were originally discovered in the Orion Nebula. Elsewhere, reliable proplyd candidates have only been found in the Carina Nebula, where harsher ionizing conditions prevail in the center of this star-forming region. Proplyds stand as unique astrophysical laboratories for studying the survival possibilities of circumstellar disks evolving in ambients dominated by extreme irradiation. Thus, studies of these special targets have ramifications for the planet formation efficiency in massive stellar clusters, where most of the stars are probably formed. This proposal aims to determine the proplyd masses in the Carina Nebula and to set observational constraints to the efficiency of extreme external photoevaporation in circumstellar disk models. The results will help us to determine whether or not proplyds subjected to extreme irradiation can host planetary systems, and whether or not the formation of planetary systems is plausible in rich and young stellar clusters. Disks around high-mass stars Disks and planet formation 2016-12-28T15:11:26.000
164 2016.2.00200.S 194 The hybrid disk phenomenon over the stellar mass range Based on ALMA observations, our group recently identified a new class of young (10-50 Myr) circumstellar disks that exhibit debris disk-like dust properties but have large amounts of CO gas of primordial origin. These "hybrid disks" may be the missing links between the protoplanetary and debris disk phases. So far, hybrid disks are only found around A-type stars. Our proposal has two main goals: (1) use CO isotopologue observations to decide on the hybrid nature of two known CO-bearing debris disks around A-type stars; and (2) look for gas in ten massive debris disks around F-M-type members of nearby young moving groups. By combining our results with previous ALMA data, we will have an almost complete survey of young debris disks with high fractional luminosity within 150 pc covering the A-M spectral type range. This will allow us to determine how the incidence of hybrid disks varies over the stellar mass range of 0.5-3 solar masses. If we find that hybrid disks are exclusive to A-type stars, this would imply that these stars can retain their primordial gas much longer, allowing significantly more time, e.g., for the in situ formation of wide separation Uranus-like planets. Debris disks Disks and planet formation 2018-09-11T18:31:19.000
165 2017.1.00914.S 496 Extending SPARKS: Exploring the origin of single high-mass protostars, and rich clusters ALMA is the only instrument to revolutionize our understanding of the early evolution of high-mass protostars, which is one of the main open issues in today's astrophysics. In our Cycle 2 project, SPARKS, we targeted a homogenous sample of 35 objects from the most massive infrared-quiet clumps selected from the ATLASGAL survey. SPARKS has been very successful reaching its science goals: we discovered the highest mass young protostars with envelope masses up to 130 AU within 2000 AU scales, and revealed excellent candidates of high-mass prestellar cores. At the same time, SPARKS revealed very intriguing fragmentation properties: single high-mass protostars with very high core formation efficiency versus typically low-mass protostars forming clusters. It is clear that now we need to understand the origin of these extrem routes of fragmentiation, and to search for more examples of these extreme fragmentation are crucial. Since the number of the most massive infrared quiet clumps in the inner Galaxy is limited, the only possible way to search for them, is to complete and extend the sample of all infrared quiet massive clumps up to 4.5 kpc from ATLASGAL. High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2020-06-23T00:00:00.000
166 2012.1.00550.S 2 First images of a protoplanetary disk around a very massive protostar One of the most important questions in the field of star formation is to test whether very massive stars (i.e., stars that will become O-type stars) form by accretion from circumstellar disks (as is the case for low-mass stars) or whether other mechanisms are at work. IRAS 16547--4247 is the most massive protostar associated with collimated jets (ATCA and the VLA) and a rotating molecular structure (SMA), which may be confirmed as a disk by observations with a higher angular resolution. We propose to undertake ALMA observations of several tracers of dense gas that will provide a critical test of the presence of an accretion disk around this source. In particular,we hope to discover the first evidence of a Keplerian signature (inner parts rotating faster than the outer parts) in a disk associated with a massive forming star. The confirmation of an accretion disk around a massive forming star will not only prove that they form by a mechanism analogous to solar-type stars but will also open the possibility of studying the physical conditions of these disks and asking whether they can form planets as well as brown dwarfs and even stars. As part of the project, we will also search for recombination lines from the powerful thermal jet associated with this source. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2016-08-17T15:04:24.000
167 2019.1.00900.S 22 How is star-formation quenched at high redshift? Looking for clues by observing post-starburst galaxies Despite decades of investigation, galaxy quenching is a missing piece in galaxy formation and evolution models. Capturing galaxies during their main quenching phase and estimating their molecular gas content are the key to constrain the processes responsible for the cessation of star formation. Here we propose to observe four post-starburst (k+a) galaxies at z=1.1-1.4 in Band 4. The optical spectra showing deep Balmer absorption lines and little or no [OII]3727 nebular emission make these massive galaxies (Mstar>1e10.6Msun) bonafide quenching objects after a star formation burst occurred <1Gyr prior z~1. With the proposed observations we aim at (i) detecting CO(3-2) and dust continuum emission at rest-frame 1mm (for individual objects and through stacking), to constrain the molecular gas masses and fractions in two independent ways; (ii) estimate the star formation efficiency and place these objects on the Schmidt-Kennicutt relation; (iii) correlate all these quantities with age, morphology, and size, so to constrain the main quenching mechanism at work at high-redshift (gas removal vs gas heating/efficiency reduction), compared to what observed in the local Universe. Starbursts, star formation, Early-type galaxies Active galaxies 2021-04-17T06:23:05.000
168 2011.0.00210.S 0 Probing Formation of Keplerian Disks around Protostars We propose to use ALMA to directly image Keplerian disks forming around protostars in the innermost envelopes. Keplerian disks have been found around pre-main-sequence stars, and intensively studied because they are most probable sites of planet formation. According to the classical picture of star formation, Keplerian disks are naturally formed as a by-product of star formation. We have been using the submillimeter array (SMA) to study the disk formation around protostars, and found that rotation-law of infalling envelopes around protostars may change at the innermost envelopes, which may suggest a hint of disk formation there. However, the sensitivity of the SMA was not high enough to directly image disks forming around these protostars. We will take advantage of unprecedented sensitivity of ALMA, which is extremely better than SMA and other mm-interferometer even in cycle 0 phase, to directly image Keplerian disks forming around protostars. Observational results will be also carefully compared with theoretical calculations of the disk formation around protostars to understand the details of the disk formation mechanism. Debris disks, Disks around low-mass stars Disks and planet formation 2013-11-15T05:44:00.000
169 2011.0.00628.S 0 Disks and complex organics in the inner regions of low-mass protostars One of the key questions that ALMA will address is how circumstellar disks form around low-mass protostars and how their physics and chemistry evolve until the planet-forming stages. We here propose to observe a range of transitions from isotopologues of common molecular species (H13CO+, C34S) and of complex organic molecules tracing the inner few hundred AU of two embedded low-mass protostars. These observations will address two coupled questions about low-mass star formation prompted by recent ground-based submillimeter interferometric observations: what is the origin of complex organic molecules around low-mass protostars and when are rotationally supported disks formed around such sources? This is made possible with the angular resolution and sensitivity offered by ALMA in its extended array in cycle 0. A key facet of these observations will be the spatial resolution and the sensitivity to reveal emission from complex molecules and relate those to the density distribution and kinematical profile revealed in H13CO+ and C34S on few hundred AU scales. Disks around low-mass stars, Astrochemistry Disks and planet formation 2014-08-12T13:52:46.000
170 2023.1.01175.V 0 Imaging M84 and Sombrero at < 50 gravitational radii: jets and accretion inflow We request EHT+ALMA 230GHz imaging of the twin jet bases of the M84 and Sombrero galaxies. Among the very few AGNs that the EHT can image at <50 gravitational radii, M84 and Sombrero were identified as having a strong (beyond SgrA* and M87) EHT flux in the March 2022 observing run. We thus have the unique opportunity to 'bridge the gap' between SgrA* and M87, and image jet base (after M87) at <50 gravitational radii, and perhaps their black hole shadows (after M87 and SgrA*) if super-resolution imaging is possible. Our immediate aim is to constrain jet launching and collimation theory with the base of the twin jets in M84 and Sombrero: specifically the morphology of the jet base, its lateral profile, core-shift from the black hole, magnetic field, and orientation. Quasi-simultaneous VLBA and GMVA imaging will enable these goals, but the EHT+ALMA observations are the crucial ingredient. The morphology and flux of the nuclear emission will also constrain emission from the accretion inflow and allow constraints on whether future 'super-resolution' imaging can image the black hole shadow in M84 and Sombrero. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 3000-01-01T00:00:00.000
171 2018.A.00009.S 38 The unique and massive SPT0348-62 protocluster at z=5.7 We propose line spectroscopy and continuum imaging towards the densest protocluster discovered so far at any redshift, SPT0348-62, made more remarkable being at z=5.7, less than 1Gyr after the Big Bang. Using ALMA in Cy4, spt0348 was shown to have at least 5 ULIRGs/SMGs detected in dust and C+ emission within 20" (integrated SFR of ~10^4 Msun/yr). Recently, we obtained a deep LABOCA image reaching 1mJy rms, which finds 6 bright sources, peaking at 870um, (870>500>350>250) consistent with the colours of the central SPT source. The proposed observations to resolve these satellite LABOCA sources are urgent and essential to obtain insight into this truly unique protocluster field. Our goals are: (i) determine whether the 6 red LABOCA sources (z~6) are in the protocluster - there is little doubt they are given the rareness of 870um-peaking sources, but redshifts are required to determine the membership and luminosity of the cluster; (ii) use the velocities of the satellites to constrain the dynamical mass of the structure. Even the assumption of fully infalling satellites requires a mass only 2 times less than the virial mass. Sub-mm Galaxies (SMG), Galaxy Clusters Galaxy evolution 2019-11-21T21:01:27.000
172 2012.1.01087.S 0 Water in the Wind of the High Redshift Radio Galaxy MRC 1138-262: Does Molecular Gas Reform in Outflows? MRC1138-262 at z=2.156 is one of the best studied radio galaxies in the distant Universe. It has all the halmarks of a galaxy that is in the "quenching phase" of AGN feedback -- it is already massive, has a large gas content, and is driving a powerful outflow. A recent detection of the 0-0 H2 S(3) line with Spitzer suggests it has a significant amount of shock heated molecular gas. By analogy with nearby AGN, the question is, how does molecular gas participate in the outflow when such gas should be easily destroyed? One possible mechanism for solving this puzzle is having the molecular gas "reform" on dust grains in the flow. The critical observation is to determine the dynamics, cooling rate, and distribution of the molecular gas in an important cooling line for shocks such as water and determine the relation of these cooling lines to the dust continuum. To begin to address this question, we propose to observe the vigorous outflow in MRC1138-262 in a water, CO(7-6), and [CI]J=2-1 lines that are redshifted into band 6 around 237-256 GHz. By using the C32-3 array, we can acheive sub-arcsecond resolution in the lines and dust continuum to match the resolution of our ground based optical emission line data. If the warm ionized gas and the molecular gas share the same kinematics and the dust has a similar morphology to both the WIM and CMM, then this support the notion that perhaps the molecular gas reforms in the wind on dust grains as has been observed locally in shock regions (e.g. Stephan's Quintet). While this program is obviously only a small step in our developing understanding of the nature of molecules in outflows, it is an important in that it begins to constrain how such molecular outflows develop and are sustained and in an environment which is much more extreme than in local AGN. As such, observing MRC 1138-262 provides strigent tests of our ideas on how the quenching phase of feedback might work. Outflows, jets, feedback Active galaxies 2015-06-06T19:47:04.000
173 2019.1.01779.T 9 The Death Throes of Massive Stars: Early Millimeter Observations of Energetic Explosions in a Dense Medium The new era of fast-cadence wide-field optical surveys has produced a cornucopia of both known and unknown transients. Supernovae are now discovered routinely within hours of explosion, providing a new window into the end-lives of stars that suggests a period of extreme instability immediately precedes core-collapse. Just this year, an entirely new class of luminous extragalactic explosions was uncovered with properties that defy nearly all basic models, but appear to be stellar explosions in dense aspherical circumstellar material (CSM). We request time on the Atacama Compact Array (ACA) to study the most nearby CSM surrounding these exotic explosions, which encodes the most recent mass-loss history of the stellar progenitor. Given the ready supply of young explosions from ZTF and ATLAS, this is a suitable time to embark on such an investigation to better understand the final stages and extrema of stellar evolution and energy production in collapsing stars. Supernovae (SN) ejecta, Transients Stars and stellar evolution 2021-01-22T14:25:06.000
174 2021.1.00767.V 0 Ultra-high resolution imaging of 3C84 3C84 is a prime target for high angular resolution studies of jet formation, due to its proximity and large SMBH mass, which provides a spatial resolution of 20 Rs. Previous 1.3cm RadioAstron space-VLBI imaging and 3mm GMVA maps show a prominent two rail jet, which is anchored in an E-W oriented compact component, perpendicular to the outer jet. With the proposed EHT+ALMA observation we address the question of the physical nature of this elongated jet base and the "true" location of the jet apex. EHT imaging with ultra-high angular resolution will allow for a number of questions to be answered: the Faraday depth, magnetic field and particle density can be estimated through the rotation measure. The location of the jet base will be precisely pinpointed. The transverse jet width and nozzle (profile) will allow for a discrimination between magnetic and/or pressure confinement in the jet launching region. Finally, the magnetic field topology and orientation will be constrained by polarisation imaging. These parameters will set important constraints for the future theoretical modelling of BH jet launching. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 2025-04-24T15:36:02.000
175 2018.1.01763.S 4 Investigating thermal diagnostics of the solar chromospheric network We propose to use observations from ALMA Bands 3 and 6 to investigate the temperature structure of the solar chromospheric network, and its evolution. Firm constraints on the actual temperature of the network elements, as well as on the duration, and spatio-temporal distribution of individual heating events, will allow us to validate current radiative-magneto-hydrodynamical models of the solar atmosphere, and assess the role of the dissipation of waves vs. magnetic reconnection as the mechanism responsible for network heating. By using temperature maps of the chromospheric network at high temporal resolution, both on disk and near the limb, we will shed light on the presence, and nature, of the ubiquitous, fast evolving spicules observed around the network. Coordinated observations will be obtained together with ALMA at up to three different observatories, providing a broad range complementary chromospheric diagnostics from UV, optical, and NIR spectral lines that can be compared to the ALMA observations to provide a more complete picture of thermal structure of the solar chromosphere. The Sun Sun 2020-02-27T03:03:32.000
176 2012.1.00781.S 2 IRAS 16272-4837: The birth of a massive protostar We propose Band 7 observations of the unique IRDC IRAS 16262-4837. This massive dense core hosts one of the most luminous IRAS sources with no counterpart cm radio continuum emission. Furthermore, Spitzer-MIPS and p-Artemis 450 micron continuum detect just two embedded protostars, each with a luminosity of an OB star. Single dish molecular lines trace a compact high velocity outflow arising from this core, and dense gas tracers show clear indication of systematic infall mortions onto the binary protostars. Thus, this source is likely one of the youngest massive protostars in the Galaxy. We will map the core in CO 3-2 and isotopologues to resolve and study the massive molecular outflows arising from this binary protostar. We will also map the core in the HCO+ and H13CO+ 4-3 lines to model de kinematic structure of the infalling envelope onto the protostars. We will use the Lime 3d radiative transfer program to model selfconsistently the infalling core and the molecular outflow cavities from both protostars in molecular lines and dust continuum. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2015-09-15T19:22:40.000
177 2021.1.01018.S 84 The Birth of Giants: Assembly of the First Massive Galaxies Over the last decade, a coherent picture of the Universe during the epoch of reionisation has started to emerge. Optical and near-IR spectra of high-redshift quasars have undoubtedly been the most polyvalent tools in the exploration of the first Gyr of the Universe. To obtain a pan-chromatic legacy sample of the brightest quasars at z~6, ESO recently awarded a Large Programme (XQR-30) to obtain optical/near-infrared spectra of the highest quality in a carefully selected sample. Here we request ~1.5 kpc (0.3") resolution ALMA [CII] imaging of this sample of quasars. These observations are critical for a number of reasons: (a) characterise the host galaxy that cannot be traced in the optical/near-infrared and spatially resolve star formation and gas surface densities; (b) provide accurate systemic redshifts that are crucial to fully exploit the optical spectroscopy; (c) pin-down the frequency of merging events in z>6 quasar hosts. Together with accurate black hole masses from XQR-30, the ALMA data will also put the targeted quasars in the framework of the black hole-host galaxy co-evolution paradigm and shed light on the formation of the first massive galaxies. High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution Active galaxies 2023-08-04T10:41:27.000
178 2016.1.00697.S 17 ALMA Observations of the Molecular Gas in the Nearest Dual AGNs Major galaxy mergers are particularly important for galaxy evolution as they can funnel fuel (gas) into the center of the galaxy triggering both star formation and an AGN. Thus, as a natural consequence, systems with 2+ accreting supermassive black holes (SMBHs) caught in the act of merging represent a critical stage in galaxy evolution. Several, 17, such dual AGN are known. The properties of the gas in these systems will offer critical clues to the conditions under which both SMBHs can be activated during these encounters and their influence on the host galaxies. We are currently performing a comprehensive multi wavelength study of the physical properties of the gas in all its phases at a critical stage in the merger process: near coalescence, when the two SMBHs are growing simultaneously. Here, we propose to use ALMA band 6 observations to map at high spatial resolution, ~100 pc, the molecular gas distribution and its kinematics in 3 merging galaxy systems for which this is currently possible. These observations will prove instrumental in determining the conditions which are conducive to simultaneous growth of both SMBHs as well as its effect on the host galaxies. Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies Active galaxies 2018-10-09T07:31:37.000
179 2019.1.01026.S 311 A Complete Continuum Imaging Survey of Strongly-Lensed, High-Redshift Starbursts From the South Pole Telescopes 2500 sq. degree survey of the southern sky, we have constructed a catalog of 81 strongly lensed high-redshift dusty star-forming galaxies (DSFGs). These sources were selected at 1.4 mm and have complete APEX/LABOCA, Herschel/SPIRE, PACS, and Spitzer/IRAC imaging, and ALMA 3mm spectroscopy. ALMA has already measured the spectroscopic redshifts for nearly all of these sources. ALMA high resolution 870 micron images have allowed the creation of reliable lens models for slightly over half of the sample. These lens models provide a wealth of information about the background source, including the magnifications and intrinsic source properties. This proposal represents the completion of this source catalog by requesting 870 micron imaging for the final 16 sources. In order to decrease the overhead fractions, we include an additional 23 sources as fillers, which will benefit from higher resolution imaging. This adds 40 min of on-source time without additional overheads, bringing the total request time to 3.58 hours. The completion of this catalog will provide a window into the nature of DSFGs and be an invaluable source for the broader ALMA community. Starburst galaxies, Sub-mm Galaxies (SMG) Active galaxies 2021-02-27T16:37:49.000
180 2012.1.00915.S 0 Measurements of high-density gas tracers in lensed submillimter galaxies Submillimeter galaxies (SMGs) constitute a population of high-redshift and heavily dust-obscured galaxies undergoing a phase of intense star formation, accounting for a large part of the total energy emitted in the Universe at far-infrared wavelengths. This population spans the peak epoch of star formation in the Universe, and is believed to be evolutionary linked to quasars and present-day ellipticals. Most star formation takes place in dense cloud cores, traced by molecular species such as HCN, HNC, and HCO+, which have some of the brightest lines after CO. Estimating the dense gas properties in SMGs using these lines is therefore essential in understanding galaxy evolution and the history of obscured star formation in the Universe. To date, the detection of such lines at high redshift has been limited mostly to the brightest quasars. We propose deep ALMA observations of the (3-2) transitions of HCN, HNC, and HCO+ in the lensed SMGs H-ATLAS J090740.0-004200 and J091043.1-000321, at z=1.5746 and z=1.784, respectively. At these redshifts, the targeted lines will fall in ALMA Band 3, and can be obtained in a single tuning in a relative short integration. Because of their large luminosities enhanced by gravitational lensing, favorable redshifts, and availability of ancillary data, these targets are well suited for the ALMA Cycle 1 capabilities. Targeting two SMGs will enable the comparison of the dense gas content between two galaxies characterized by different CO excitation, and will provide a faster progress in this area than has been previously possible. The three chosen lines will provide us with the necessary diagnostics to constrain the total amount of dense gas and its physical properties, estimate the age of the starburst, and look for indications of AGN activity. We aim to obtain the first multi-line diagnostic set for dense gas in high redshift SMGs, showcasing the potential of ALMA to break new ground in the study of obscured star formation at high redshift. Sub-mm Galaxies (SMG), Galaxy structure & evolution Galaxy evolution 2015-03-10T19:21:32.000
181 2023.1.00750.S 0 Hii gas at Cosmic Noon: An ACA survey of OIII at z = 2.5 to 5 We aim to do a survey of the [OIII] 88um line in ten dusty star-forming galaxies (DSFGs) detected from Herschel surveys. This will be the first comprehensive follow-up of [OIII]-emission in DSFGs, and we target specifically the peak of cosmic star-formation rate to probe the fraction of high-ionization gas in their dusty photo-dissociation regions (PDRs). These galaxies have well-characterized dust, CO, atomic carbon and ionized carbon emissions from ALMA and ACA. While studies find near-homogeneous dust properties, the varying depletion times, excitation conditions and morphologies suggest a diverse population. In an effort to understand the intrinsic variations in this population, we propose an ACA survey to probe the only PDR region missing from current surveys: the high-excitation conditions seen through [OIII] 88 micron emission. We select a sample of ten luminosity-limited Herschel galaxies at Cosmic Noon (z = 2.5 to 5) with good atmospheric conditions. Finally, the additional dust observations will enable accurate dust continuum fitting, which is currently limited by the poor resolution of the Herschel data. Sub-mm Galaxies (SMG) Galaxy evolution 3000-01-01T00:00:00.000
182 2022.1.01135.S 0 Spatially resolved deep submm follow-up of z > 6 low-luminosity quasars with approved JWST's stellar light observations In this program, we will measure [CII] and FIR continuum emission of a sample of 8 low-luminosity quasars at z > 6. All of our sample will be observed by JWST to robustly measure the stellar light of their host galaxies. Combined with the stellar mass data, we will discuss the location of these quasars relative to the star-forming main sequence. Our high resoliution (0.3") observations will also provide a spatially resolved picture of specific star formation rate. These will tell if the quasar feedback (quenching) is in action particularly around the nucleus. As these quasars are likely to be hosted by lower mass galaxies, we can perform a fair comparison of the host galaxy properties with non-AGN normal galaxies (such as provided by ALPINE and REBELS programs studying at comparable cosmic times): we will identify the distinctive properties of quasar hosts, which is crucial to understand the triggering mechanism of quasar activity. Owing to the high resolution, we will also perform dynamical modelings of the host galaxies to obtain their dynamical masses. With these, we will test the usual assumption in z > 6 quasar studies, dynamical mass ~ stellar mass. High-z Active Galactic Nuclei (AGN) Active galaxies 2024-09-15T06:34:19.000
183 2016.1.00345.S 96 The Disk/FLow System in the Massive Protostar IRAS 18566+0408 The presence of accretion disks and ionized/molecular jets during the formation of B-type stars is a well established fact, but whether this is also the case for high luminosity protostars which will form O-stars is still debated. We propose 0.3" resolution molecular line and continuum observations of IRAS18566+0408 which is one of the most luminous protostars in the Galaxy. We have observed this object with CARMA at 1" resolution and established the presence of a high density and temperature core, with high pressure gas participating in the flow. The proposed observations will allow to study the dense gas on the scale of 2000 AU which is necessary to investigate the formation of individual stars. Besides determining the multiplicity in this core, we will search for evidence of an accretion disk, and constrain its physical properties. We have already obtained matching resolution VLA maps of the ionized jet in IRAS18566+0408, and the ALMA data will allow to study the relationship between ionized and molecular gas, and how the jet connects to the large scale bipolar flow observed in CO(2-1). Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2018-04-10T18:10:15.000
184 2018.1.00589.S 77 A Resolved Measurement of the (Break of) HCN, H_2, and Star Formation Relations in a Local Starburst Environment Galaxies follow several scaling `laws' between the amount of star formation and its available fuel. Samples of luminous Galactic clumps follow the extragalactic Gao-Solomon relation between HCN (proxy for the amount of dense gas) and bolometric luminosity (star formation rate). These clumps are key because they dominate the star-formation rate of our Galaxy, and presumably correspond to the typical environments in vigorous star-forming galaxies and starbursts. We propose for the first resolved measurement of scaling laws between HCN, H2 and star formation rate in one of the most luminous star-forming clumps in the Milky Way (W49N, Lbol>10^7 Lsun), including two J-transitions and isotopologues to disentangle optical depth and excitation effects. Our single-dish measurements show that the extragalactic relations are valid in this environment at clump scales. The ALMA data will serve to measure at which scale these relations break, somewhere between the scale of the full clump (6 pc) and of star forming cores (0.1 pc). The results will give important insight on the possible origin of extragalactic star formation relations as the outcome of the physics within cluster forming clumps. Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2020-02-18T17:56:19.000
185 2022.1.01262.S 57 What is the role of major mergers in galaxy formation and evolution? In the local universe, the role of major mergers in triggering enhanced star formation is well-established, primarily based on the evidence that the morphology of many IR-bright galaxies are highly disturbed. In contrast, the significance of major mergers in forming stars at high redshifts is under debate, due to increasing observational evidence of z ~ 1-3 galaxies with copious star-forming clumps without an apparent equal mass companion. However, the fraction of major mergers may be significantly underestimated because visually distinguishing late-stage mergers or post-mergers from isolated systems is exceedingly difficult. We address this problem by mapping CO(2-1) emission at 50 pc scales in 14 disk-like post-mergers in the local universe. By detecting and analyzing the molecular clumps and disk-wide structure in a sample of post-mergers and comparing it to nearby isolated early and late-type systems, we will address the role of major mergers in the formation of molecular clumps in the extended disks. This is particularly important in understanding the formation process of clumpy starbursts and ultimately the role of major mergers in the history of cosmic star formation. Merging and interacting galaxies Galaxy evolution 2024-01-11T13:24:16.000
186 2019.1.00178.S 4 Measuring the magnetic field through CN Zeeman effect in G31.41+0.31 We want to directly estimate the magnetic field strength towards the Main core in G31.41+0.31 by using the Zeeman splitting of CN. G31.41+0.31 is one of the clearest examples of an hourglass-shaped magnetic field morphology in a high-mass star-forming region. Taking advantage of the simple magnetic field morphology, we propose to observe several transitions of CN at 1mm and 0.2 arcsec of angular resolution and estimate the magnetic field strength along the line of sight. Since CN is a paramagnetic molecule, it shows a strong Zeeman effect under the influence of the magnetic field. Previous SMA 1 arcsec observations have clearly detected CN in absorption towards this core, while previous ALMA 0.2 arcsec dust polarization observations have allowed us to obtain a very rough estimate of the magnetic field by means of the Davis-Chandrasekhar-Fermi method. The Zeeman splitting will allow us to obtain a precise measurement of the magnetic field strength along the line of sight to better constrain the mass-to-flux ratio and to assess the importance of the magnetic field in the dynamics of the Main core in G31. High-mass star formation ISM and star formation 2022-12-22T17:18:09.000
187 2023.1.00402.S 0 Measuring accurate gas masses of the planet-forming disks in Lupus We propose to carry out a systematic survey of N2H+ in a large, mass-limited (Mdust > 1 Mearth, 13CO detected) sample of protoplanetary disks to provide CO-to-H2 ratios and accurate gas disk masses in the Lupus star-forming region. Previous 13CO, C18O and dust continuum observations show CO to be underabundant by up to 2 orders of magnitude beyond what is expected from freeze-out and (isotope-selective) photodissociation. Whether this means that planet-forming disks are generally gas-poor or that carbon is locked up in other compounds than CO is currently unknown. N2H+, a sensitive probe of CO-poor gas, has been shown to directly measure the CO-to-H2 ratio in disks and is thus uniquely positioned to answer this question. Our observations of N2H+, supported by thermochemical models, will allow us correct existing CO-based gas masses for any underabundance of CO, thus providing accurate gas masses. This will allow us to discriminate between the two alternatives (gas poor vs low CO) that have radically different implications for prospective planet formation. Our observations will provide a definitive answer to the ubiquitous low CO - gas mass conundrum posed by planet-forming disks. Disks around low-mass stars Disks and planet formation 3000-01-01T00:00:00.000
188 2016.1.00440.S 31 A Model Independent Study of Turbulence and Temperature in TW Hya Despite being a cornerstone of the global evolution of a protoplanetary disk and the subsequent formation of planets, turbulence in disks is incredibly poorly constrained observationally. All derivations thus far have been limited to model-fitting, yielding a global average or simple radial power-law profile describing the turbulent line broadening. Theoretical models of turbulence predict strongly localised variations which would not be captured with such methods. We propose to measure, in a model independent way, therefore free of bias from prior assumptions about the disk structure, the radial profile of turbulent line broadening in the TW Hya disk. This will allow us to confront directly models of turbulence and remain unbiased from the distinctly non-parametric features observed in TW Hya in mm-continuum and scattered light. Disks around low-mass stars Disks and planet formation 2018-04-12T12:36:02.000
189 2013.1.00291.S 6 The emergent low-mass cluster B59: how to beat magnetic fields B59 is the only star-forming site in the quiescent and magnetized Pipe nebula. It contains a small cluster of low-mass protostars and a very twisted magnetic field in comparison with the more pristine regions of the cloud. We propose to perform a detailed dynamical study of B59 using linear polarization observations. These data will reveal the magnetic field morphology in sources in B59 wich are at distinct evolutionary stages: Class 0, I and II. We want to trace the evolution of the magnetic field properties in the three stages. We expect to resolve the field morphology at the dust envelope of Class 0 objects and at the circumstellar disks at Class I and II objects. Since all targets belong to the same (low-turbulent) parental cloud, we will be able to test predictions of magnetized molecular cloud models. As a complement, molecular line data will trace the kinematics of the cores in order to better constrain the possible ambiguity of projection effects in the polarization data. Low-mass star formation ISM and star formation 2015-11-05T00:00:00.000
190 2019.1.01230.S 162 Studying the coronal properties of complete volume-limited sample of accreting supermassive black holes The compact radio/mm emission observed in most Active Galactic Nuclei (AGN) is thought to be created by self-absorbed synchrotron emission from the accretion disk corona, the region which is also responsible for the X-ray emission. If this was confirmed, then the nuclear mm-emission could be an excellent tracer of AGN activity and of the AGN bolometric luminosity, being largely unaffected by obscuration. With the goal of understanding the origin of the nuclear 100 GHz emission, and its relation with the X-ray radiation, we propose to observe with ALMA, for the first time, a complete sample of nearby AGN with spatial resolutions between 1.5 and 23 pc. Only the exquisite resolution of ALMA can probe these scales, necessary to infer the coronal emission. A tight relation between 100 GHz and X-ray emission would provide very compelling evidence that the same emission mechanism is at work in the two bands. This would also suggest that the detection of flat nuclear mm emission is a reliable tracer of AGN activity, and would provide a new proxy of the bolometric AGN power, possibly more reliable than the X-rays. Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies Active galaxies 2022-09-15T07:59:57.000
191 2023.1.00251.S 0 Unveiling a hidden gem: an extraordinarily bright strongly lensed galaxy behind Milky Way dust clouds We propose a B3 and B4 spectral scan to confirm the redshift of J154506, an exceptionally bright (~130mJy at 500um) and massive extragalactic source at redshift z~5-6.5. ACA spectral scan capabilities, targeting the CO /[CI]/H2O lines over a wide redshift range, are a highly efficient tool for unambiguous redshift confirmation. This will allow deriving a robust lensing model, reconstructing the source plane, and accurately determining its intrinsic properties. In addition, the targeted lines (at least two will be detected) will lead to immediate scientific results such as the determination of gas density and temperature, and robust estimation of the total mass of the molecular gas. Finally, J154506's highly lensed nature will enable spatially resolved follow-up studies that are essential for uncovering the mechanisms driving rapid mass buildup in the early Universe. Starburst galaxies, Sub-mm Galaxies (SMG) Active galaxies 2024-12-24T12:37:21.000
192 2018.1.01366.S 55 Unveiling chemical compositions of high-mass star-forming cores in low metallicity galaxies Interstellar chemistry in low metallicity environments is crucial to understand chemical processes in the past universe. Prior to this proposal, we conducted spectral line surveys toward molecular clouds in nearby low metallicity galaxies, LMC and SMC, with single-dish telescopes. As a result, we found that molecular clouds in LMC experience chemical processes different from those in our Galaxy. However, the beam size of single-dish telescopes (5-10 pc at LMC) is too large to resolve internal structures of molecular clouds, and emission from star-forming cores (~0.1 pc), which reflect the chemical compositions of molecular gas associated with newly formed stars, is almost diluted out. Here we propose ALMA band 6 and 7 spectral line observations toward high-mass YSOs in LMC/SMC to unveil the impact of low metallicity environments on chemistry of star-forming cores. This proposal should elucidate a possible link between chemical properties of dense molecular gas and metallicity of the host galaxy. Furthermore, this program has potential to identify a hot molecular core in low-metallicity galaxies, which should help understand chemical diversity of complex molecules in our universe. Astrochemistry, Magellanic Clouds ISM and star formation 2020-01-08T08:39:32.000
193 2016.1.01363.S 97 Widespread SiO in IRDCs: Cloud-Cloud Collision Formation of Molecular Cloud Filaments? Infrared-Dark Clouds (IRDCs) are filamentary molecular clouds believed to represent the initial conditions of massive star and star cluster formation. Several scenarios have been proposed to explain the filamentary structures observed for these clouds: shock-induced formation, flow-driven formation, cloud-cloud collisions ad magnetically-regulated formation. Among them, the cloud-cloud collision scenario predicts that already molecular clouds collide at velocities of some km s-1, yielding cold and filamentary IRDC structures. As a result, relics of the initial cloud-cloud interaction are expected. Recent single-dish high-sensitivity mapping of the SiO (2-1) line toward two quiescent IRDCs (Clouds H and G) shows that this emission is widespread over parsec-scales across both clouds. Here, we propose to image the emission of SiO (2-1) toward Clouds H and G to clearly establish whether this emission arises from the possible inter-shocked layer originated in the initial cloud-cloud collision, or whether widespread SiO is associated with a population of low-mass protostars that remain deeply embedded and undetected at all wavelengths toward these clouds. Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2019-04-01T00:00:00.000
194 2021.1.01156.V 0 Towards a sample of SMBH shadows, rings, accretion flows and jet bases: exploratory EHT+ALMA flux measurements The photon ring around the black hole in M87 (billions Msun, powerful jet) has been imaged with the Event Horizon Telescope (EHT), and exciting results on SgrA* (millions Msun, no/weak jet) are in the pipeline. Here we request 6.4 hours of ALMA time to enable EHT+ALMA 230GHz nuclear flux measurements of 8 black holes, as a step towards observing all 16 black holes with bright enough 43 or 86~GHz cores which can be imaged at <100 Schwarzschild radius resolution with the EHT. Our immediate aim is to identify sources in which near-future deep EHT+ALMA imaging can: (a) resolve the jet base thus providing unique and crucial constraints to jet launching theory over a larger parameter space (mass, spin, accretion rate, jet orientation and power); (b) resolve accretion flows and orbiting hotspots, providing unique constraints to accretion theory; and (c) identify SMBHs whose photon rings can be resolved using super-resolution techniques developed by the EHT Collaboration, thus providing additional constraints to gravity theories. This proposal is thus a first step towards leveraging the transformational results coming from M87 and SgrA* to a multi-parametric sample of black holes. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 3000-01-01T00:00:00.000
195 2022.1.01039.S 32 CONICS: Cosmic Noon ISM Conditions Survey The COsmic Noon ISM Conditions Survey (CONICS) is a comprehensive survey of the mass and conditions in the cold interstellar medium (ISM) of 11 star-forming galaxies during the peak of cosmic star formation (z=2-3). Carefully drawn from optically-selected CO(3-2) surveys, these galaxies form the largest, representative sample of star-forming galaxies at this epoch and benefit from exquisite multi-wavelength data. With only two tunings, we will efficiently measure the CO(4-3)+[CI](1-0) and CO(7-6)+[CI](2-0) emission and underlying dust continuum in Bands 4 and 6, providing a homogeneous dataset that is sufficient to constrain the latest generation of radiative transfer models of the cold medium. This program will provide fundamental insights into the boundary conditions for star formation during the peak of the cosmic star formation history by measuring (i) the total mass in cold gas and dust (ii) the physical conditions in the cold molecular medium (e.g., temperature, density). Building on years of investments with ALMA and NOEMA, CONICS will provide the most comprehensive survey of the gas masses and ISM conditions in galaxies at cosmic noon to date. Starburst galaxies, Galaxy structure & evolution Active galaxies 2024-01-12T22:35:55.000
196 2021.1.01594.S 23 Spectroscopic Follow-up of Two Luminous Galaxy Candidates in the Epoch of Reionization The exploration of the early universe and luminous sources therein has been significantly advanced through synergistic strategies across multiple facilities. Remarkably, sub-mm follow-up observations by ALMA of high-z source candidates selected from UV-to-near-infrared observations have opened up a new frontier and enabled us to witness the early evolution of galaxies at the early stage of cosmic reionization. We here propose follow-up observations of 2 luminous (MUV~-22) galaxy candidates at z ~8 with ALMA Band 6. These galaxies were selected from one of the approved Cycle1 JWST GO programs. Our goal is to securely determine the redshift of these galaxies via spectral scanning, targeting the [C II] 158m line. The line is detectable with ~30 minutes on-source exposure per source. Detection of [C II] by our observations will confirm these galaxies as one of the most luminous sources in the epoch of reionization and enable future investigation of their ISM properties with the spectroscopic dataset provided by JWST/NIRSpec. Even non-detection will be a valuable outcome, by providing the JWST GO team an opportunity to finalize their observing targets. Lyman Break Galaxies (LBG), Starburst galaxies Galaxy evolution 2023-07-13T17:57:41.000
197 2015.1.01301.S 50 Gas Dissipation through Disk Evolution in Transitional Disk Systems with Large Cavities It is widely believed that protoplanetary disks dissipate inside-out. In particular, as an intermediate phase from gas-rich primordial disks to gas-poor debris disks, transitional disks that have a cavity in the central region of the disk could be ideal testbeds to catch gas dissipation in progress within their cavities. Here we propose band 6 (1.3 mm) observations of fifteen transitional disk systems with a relatively large (r >0.''15) cavity in dust continuum, especially focusing on CO line emissions (12CO, 13CO and C18O) at a spatial resolution of 0.''2 to estimate the amount of the gas in the cavity of dust continuum. Our goal is to obtain observational evidence of gas-dissipation in progress among transitional disk systems. To determine to what extent the gas is still contained in the cavity, we measure the `depletion facor' of the CO gas, i.e., the flux ratio of the-gas-outside-the-cavity to inside-the-cavity. Systematic and quantitative comparisons of the gas in the cavity will enable to help our understanding of the disk evolution in transitional disk systems. Disks around low-mass stars Disks and planet formation 2018-03-02T00:44:21.000
198 2018.1.01050.S 33 Heavily Resolving The Molecular Gas Layer in a Protoype of Edge-on Galaxies: NGC 4565 We propose to directly measure the thickness of molecular gas layer in an edge-on galaxy, NGC 4565. This measurement requires high linear resolution (0''.5), high sensitivity (0.15 K for 10 km/s channel width), and wide spatial coverage (600'' by 30''), which is possible by ALMA in a sensible integration time (17 hours for 12-m array). The thickness of molecular gas layer is important in numerous studies of star formations (i.e. deriving the volume density of molecular gas) and galaxy structure (i.e. comparison to the expectation from hydrostatic equilibrium). This measurement would also be an important constraint to study the star formation efficiency per free fall time in the sample of ALMA PHANGS Large Program. Previous measurements have only barely resolved the vertical distribution of molecular gas, or only limited to the central region. Therefore, we propose to overcome these limitations by observing the whole stellar disk (14 kpc in radius) with finer resolution (25 pc) and better sensitivity (about 1 Solar mass per square parsec). Spiral galaxies Local Universe 2023-02-04T14:27:30.000
199 2012.1.00538.S 1 The physical structure of a massive and dense cold core Despite significant efforts to understand the formation of massive, clustered stars, we lack a clear understanding about its nature. Two very different scenarios have been proposed for this process: Core Accretion and Competitive Accretion. The former requires a centrally concentrated monotonicaly collapsing cloud, while the latter, a distribution of smaller cores spatially distributed within the cloud. Here we propose to observe G305.136+0.068, a massive and dense cold core (T~15 K), which by being isolated constitutes an ideal case for observationally constraining these scenarios. Thanks to the new capabilities offered by ALMA, we can study in detail the mass distribution and kinematics of the core through the mapping of different molecular lines: N2H+ will trace the physical and kinematic conditions of the densest part of the core, while HCO+ and CS will allow us to trace the outer and less dense regions. For the first time, we will achieve the necesary spatial resolution to distinguish between Core and Competitive Accretion and therefore, advance in our understanding of massive star formation theory. High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2015-05-30T12:10:08.000
200 2021.1.01311.S 8 Confirming a z~6.9 Sub-mm Galaxy in COSMOS Hosting a Radio-Loud AGN We propose Band 6 observations to confirm the redshift of a dusty, massive z~6.9 galaxy identified over the COSMOS field that shows multiple signatures of hosting a radio-loud AGN. We will employ a [CII]158mum scanning strategy has proven to be highly successful at spectroscopically detecting massive reionization-era galaxies with ALMA. Upon confirmation, this source will be not only the highest-redshift radio-loud galaxy yet discovered, but also the highest-redshift unlensed sub-mm galaxy (L_IR ~ 3e13 L_sol). Because this galaxy was selected over a relatively small field, confirming its high-redshift nature would suggest that radio-loud (non-quasar) AGN may be a significant accretion mode for supermassive black hole formation, helping understand how these objects formed so rapidly in the early Universe. Our observations will simultaneously provide morphological and kinematic maps of the gas and dust within this highly obscured system, constraints on its small-scale environment via serendipitous [CII] detections from ~50x lower-mass neighboring sources, and improved insight into contribution of dusty galaxies to the cosmic star formation rate budget at z>6. Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) Galaxy evolution 2023-01-07T22:16:14.000
201 2018.1.01218.S 34 Disk substructures in TW Hya: Optically Thick or Large Grains? Our understanding of protoplanetary disks is rapidly changing as complex substructures are now routinely revealed by ALMA. However, the role of disk substructures in the dust evolution process is not well understood. Here we request Band 3 observations with 0.05arcsec of angular resolution toward the closest protoplanetary disk, TW Hya. Previous ALMA observations of TW Hya show multiple rings that are consistent with either optically thick emission, or optically thin emission from cm-sized dust grains. We plan to resolve the disk substructure at the longest wavelength (hence optically thinner emission) probed by ALMA. Our proposed observations, combined with previous data between 0.87 and 7 mm, will allow us to map the spectral index in the disk and constrain the dust density and size distribution in the rings. This will inform us whether disk substructures are trapping large dust grains and enabling dust growth beyond cm sizes. Confirming this scenario would have a critical impact on our theories of planetary formation. Disks around low-mass stars Disks and planet formation 2020-11-27T15:33:53.000
202 2021.1.01006.S 32 Revealing the cold ISM properties at 150pc scales in a strongly lensed UV-bright star-forming galaxy at Cosmic Noon Strong gravitational lensing has become a prime tool for resolving the star-forming interstellar medium of high redshift galaxies down to sub-kpc scales. While the first ALMA studies focused on intrinsically luminous lensed targets, recent work has pioneered the study of star formation and molecular gas in fainter, lower mass and lower metallicity galaxies, which are more representative of the global population at z~2. Here we propose high resolution imaging of CO and dust continuum emission of a strongly lensed, but otherwise typical, main sequence galaxy at z=2.4. Recent HST and SINFONI observations reveal ionized gas outflows arising from an active nucleus, making this target a unique opportunity for investigating the effect of an AGN on the molecular gas. The proposed observations will allow us to measure the resolved star formation law, the sizes and the relative distributions of gas and dust. The results of this program will help us build a complete picture of a typical star-forming galaxy at cosmic noon by connecting stars, gas and dust at 150pc scales. Lyman Break Galaxies (LBG), Gravitational lenses Galaxy evolution 2024-01-09T17:38:10.000
203 2013.1.00198.S 25 Chemical Abundances in Planet-Forming Disks: The Carbon Reservoir Recent observational results have suggested that the CO abundance in the TW Hya disk is well below the ISM value. This result was enabled by a detection of HD by Herschel that set strong constraints on the total gas content thereby opening a pathway to explore chemical abundances in protoplanetary disks. We propose resolved ALMA observations of simple carbon bearing species in two protoplanetary disks systems of disparate age (TW Hya at 3-10 Myr and DM Tau at 1 Myr) that each have HD detections. We will target transitions of C2H, C3H2 and H2CO (TW Hya; to be combined with cycle 1 observations of C18O) and C2H, C3H2, CH3OH, and C18O (DM Tau) with enough resolution to explore chemical gradients within each disk. Armed with the additional information from HD and dust continuum we will characterize radial abundance gradients relative to H2 (from HD) and CO (from C18O) in each disk in the emissive layers. With these data we can start to explore the question of where the carbon resides in protoplanetary disks, while also setting more stringent constraints on the distribution and evolution of chemical abundances. Astrochemistry ISM and star formation 2016-08-20T00:25:41.000
204 2015.1.01199.S 25 A Novel Approach to Observing the Gas-Dissipation Timescale of Protoplanetary Disks Determining the gas-dissipation timescale in protoplanetary disks is an important quantity for understanding the formation of planetary systems, in particular gas giants. Traditional tracers of the H2 rich gas, such as CO, provide mass estimates with large uncertainties that may increase with disk age. To counter this we use our solar system as a template where there is a clear enhancement in the C/N ratio relative to the solar value in meteorites and comets. This is due to a decrease in the amount of incorporated nitrogen. Thus N may be preferentially available in the gas over longer timescales than C, making N-bearing molecules better tracers of the mass in mature protoplanetary disks. We propose a pilot study to observe N2H+ emission in two ~5-11 Myr-old disks in the Upper Scorpious OB association that have previous ALMA dust continuum and CO measurements. Our aim is to evaluate the ability of N2H+ to act as primordial gas (mainly H2) tracer and our estimates suggest that we have sensitivity to H2 gas masses > 0.004 Msun. Positive results would lead to a future survey of N2H+ in a large number of disks to constrain the gas-dissipation timescale. Disks around low-mass stars Disks and planet formation 2017-04-19T21:56:47.000
205 2016.1.01134.S 9 Completing the submillimetre portrait of LAB1 In Cycle 2 we obtained deep Band 7 observations of the original 100kpc Lyman-alpha Blob SSA22-LAB01 (z=3.1). The 0.3" resolution 850um map revealed twin extended (1"-2") submillimetre sources embedded in the heart of the LAB. However, the ALMA observations raise a new mystery: nearly 50% of the total flux measured with a single dish (JCMT/SCUBA-2) is missing in the ALMA map. There is strong evidence for highly extended (possibly up to 40kpc) dust emission in this system with total flux ~2mJy. This dust could be associated with a population of faint satellites, with the circumgalactic medium (CGM), or with tidally disturbed material around the two central sources. These scenarios are testable, and would yield important information on the large-scale distribution of dust around galaxies forming in massive halos at z~3. We will map the extended dust with new Band 7 observations that will bridge the uv-plane coverage between the single dish and Cycle 2 observations, completing the submillimetre continuum portrait of this remarkable object. Lyman Alpha Emitters/Blobs (LAE/LAB) Galaxy evolution 2018-04-27T03:05:13.000
206 2019.1.01329.S 71 The physical nature of massive quenched galaxies at z>3.5 Determining why galaxies stop converting gas into stars is a key unanswered question of galaxy evolution. Multiple processes could play a role in quenching a galaxy, yet evidence is scarce to favor one explanation over the other. Using NIR spectra, we recently discovered quiescent galaxies in the first billion years of the Universe, with properties that models fail to predict. Studying these systems further is necessary to understand the first appearance of quiescent galaxies in the Universe, and give constraints on the quenching models. We propose dust continuum and [CI] observation with ALMA for the spectroscopically confirmed massive quenched galaxies at z > 3.5. Deep dust continuum imaging at Band-7 will enable us to investigate whether these red and massive galaxies have strongly dust-obscured star-formation or are truly quenched. We will also conduct deep [CI] spectroscopy at Band-3 to investigate their cold gas fractions, which will allow us to disentangle the quenching processes with different timescales. These data will provide us with deep insights into how galaxies stop star formation and massive quenched galaxies first appear in the early Universe. Galaxy structure & evolution Galaxy evolution 2021-02-20T10:21:11.000
207 2021.1.00347.S 20 Triggering and supression of star formation in recent gas-rich minor mergers Galaxy mergers are a crucial part of our galaxy evolution paradigm. Gas-rich & gas-poor mergers have been well studied. However a third intermediate class exists, where one of the merging objects has gas, and the other does not (gas-rich+gas-poor). Such mergers are quite common at low redshift, but have not been well characterised. A recent study suggests that mergers where a gas-rich minor companion is accreted onto a gas-poor central actually lead to very low efficiency star formation, in stark contrast to the starburst often observed in purely gas-rich mergers. In order to understand this phenomenon we here propose to observe a carefully constructed sample of gas-rich+gas-poor & gas-rich minor mergers with ALMA, revealing the compactness/dynamical state of their molecular reservoir, and how this relates to their star formation efficiencies, & those of a robust control sample selected from the literature. A short investment of ALMA time will allow us to reveal how gas gas-rich+gas-poor mergers differ from better studied gas-rich mergers, and lay the ground work for future observational & theoretical efforts to fully resolve the physical processes behind these differences. Merging and interacting galaxies, Early-type galaxies Galaxy evolution 2023-10-26T12:46:57.000
208 2013.1.00179.S 4 Binary properties encoded in the circumstellar spiral pattern of AFGL 3068 Theoretical models show the formation of a spiral pattern in the circumstellar envelope (CSE) of an AGB star due to the presence of a binary companion. This spiral pattern preserves the information about the orbital motion of binary stars, and can be used to constrain key binary properties (stellar masses, separation, and orbital inclination) using high-sensitivity high-resolution interferometric observations of the molecular line emission from the CSE. We propose to use ALMA to observe the circumstellar CO(2-1) line emission from the CSE of an extreme carbon star AFGL 3068 to obtain the critical 3D information of its spiral pattern. This pattern has only been observed in a dust scattered light image (thus 2D), leaving a degeneracy in the determination of the binary parameters. The proposed observations will provide new diagnostics to significantly extend the method of mass determination for embedded stars and their companions using our newly-developed model. The resulting determination of the binary properties will be an important step towards theoretical investigations of the effect of binarity on late stellar evolution and the onset of bipolarity at the end of the AGB phase. Asymptotic Giant Branch (AGB) stars Stars and stellar evolution 2016-12-28T06:07:51.000
209 2021.1.00720.S 270 Establishing a timeline for the high-mass star-formation process Studying the first stages of high-mass star formation is observationally demanding, because the entire early evolution takes place while the young stellar objects (YSOs) are embedded in their parent cloud. In recent years it has become possible to arrange high-mass star forming regions (HMSFRs) on a relative timeline. This, however, does not give any information on the actual age of individual YSOs. With the high-resolution obtainable with ALMA and (new) chemical models, one can better constrain the actual age of these objects. In cold, dense material molecules are locked onto grains, but evaporate into the gas phase at different temperatures, depending on the chemical properties of each species. When this happens their gas phase abundance increases drastically. With the continued heating by the YSO the evaporation fronts will expand making it possible to assign an age to individual YSOs, with the aid of chemical models that link the size of the evaporation region and the luminosity of the YSO to an actual age. We therefore want to observe selected molecules in HMSFRs in different evolutionary phases and compare the derived column densities with the model results. High-mass star formation, Astrochemistry ISM and star formation 2023-05-03T14:40:28.000
210 2015.1.00311.S 30 ALMA probes the SagA* Accretion We propose to search for HI 30alpha recombination line emission in the accretion zone of the Galactic Center supermassive black hole SgrA*. These observations are stimulated by the the detection of broad HeI line emission in the NIR (Hall etal 1982). The ALMA sensitivity is such that we will easily detect a 0.001 solar masses of HII if the gas density is 10^6 cm^-3 and these numbers are consistent with what one might expect in the accretion zone of SgrA*. This technique offers a vital new window to SgrA* -- X-ray observations can't probe the 10^4 K gas. The submm recombination lines have higher spontaneous decay rates than the cm-wave lines; they therefore can more reliably probe the very high densities which will be in proximity to SgrA*. If the line is detected, it will yield estimates for the mass of ionized gas and the radius where this gas resides from the velocity extent of the emission. The requested resolution of 0.2 arcsec is needed to resolve the emission on the scale of 10^16 cm. Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei Active galaxies 2017-06-28T18:16:37.000
211 2018.1.01540.S 16 Multiscale tests of dense filament and core formation in a magnetized molecular cloud Molecular clouds, dense filaments, and cores all form out of a magnetized ISM; however the degree to which magnetic fields influence the formation of dense cloud substructures is still an active topic of debate. Here we propose a comprehensive observational study of one of the highest column density regions in the Vela C giant molecular cloud, in which we will directly link (a) cloud-scale magnetic fields measured by extremely sensitive balloon-borne polarimetry, (b) filament scale magnetic fields traced by APEX polarimetry at 870 microns, and (c) sub-filament and core scale fields from ALMA band 4 polarimetry for a 0.1 pc embedded clump. Our proposed observations will trace the magnetic field from 0.007pc to 50pc. By measuring the degree of order in the magnetic field and the orientation of the field direction relative to cloud structure on different size scales, we will determine the dynamical importance of the magnetic field in the different density regimes within Vela C. Intermediate-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2020-03-07T21:28:18.000
212 2016.1.00901.S 3 Seeing to the Event Horizon: Terahertz Spectra of Sagittarius A* The millimeter/submillimeter spectrum of the Galactic Center supermassive black hole, Sagittarius A*, originates from within a few Schwarzschild radii of the event horizon. Determination of the turnover frequency and spectral index after the turnover is critical for assessing the optical depth of the emission and the maximum electron temperature present in the accretion flow and/or jet. These measurements will set important boundary conditions for models of the Event Horizon Telescope images of Sgr A*, directly enabling constraints on the nature of accretion and outflow, black hole spin, and tests of general relativity. Specifically, we propose to obtain spectra at frequencies from 230 to 900 GHz (bands 6, 9, and 10) of Sgr A*. There are only limited prior observations for Sgr A* up to 690 GHz and no interferometric observations at 900 GHz. Our ALMA Cycle 2 observations show that the spectrum of Sgr A* is flat between 230 and 345 GHz (bands 6 and 7). The spectrum must turn over steeply at THz frequencies in order to connect with near infrared spectra. Only ALMA can provide this broadband high frequency spectrum and give insights into the event horizon structure of Sgr A*. Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei Active galaxies 2018-05-01T00:13:46.000
213 2019.1.01407.S 83 Mystery in Deuterium fraction - An evolutionary picture of deuterium chemistry in protostellar phase We propose to observe H2D+ emission using ACA toward 3 protostellar cores in Perseus. The deuterium fraction N2D+/N2H+ has been used as an evolutionary indicator for protostellar cores as it decreases due to the heating from the central protostar. However, in episodic accretion, the thermal history in protostellar phase becomes more complicated. The cloud cores can be heated up and cooled down several times such that the N2D+/N2H+ ratio being an evolutionary indicator is unclear. Based on our previous CO, DCO+, and N2D+ ALMA survey in 25 protostars, we propose an evolutionary picture of protostellar cores: from a cold-center protostellar core at pre-epidosic accretion phase evolves to a warm-center protostellar core after starting episodic accretion. To confirm that, we propose to observe H2D+, the parent molecular ion of N2D+ and DCO+, toward three representive protostars (Per-emb-4, 20, and 51) from our survey. We will use the H2D+ distribution to check our proposed scenario. This result would provide a standard evolutionary picture of the deuterium fractionation at the protostellar phase. Low-mass star formation, Astrochemistry ISM and star formation 2022-10-01T04:18:22.000
214 2018.1.01429.S 69 The first molecular line inventory in hybrid disks The transition from the late phase of protoplanetary disks to young debris disks remains a poorly explored evolutionary stage of planet-forming disks. The new class of "hybrid" disks, recently discovered by our team, includes disks with debris disk-like dust properties but having primordial gas content. These disks may represent the protoplanetary to debris disk transition. In order to establish how the chemical properties evolve, we propose to study all four hybrid disks discovered so far, together with five evolved Herbig Ae systems with relatively low gas content as comparison targets. The observations will provide the first inventory of the most important and best observable molecules in these disks. We will characterize their morphology and kinematics, and perform a detailed chemical analysis using our ANDES and ALCHEMIC chemistry codes adapted to these disks. Our program will reveal the chemistry of an independent evolutionary path for the gas component around A-type stars. The measurements are expected to provide final proofs that the gas in hybrid disks is the direct residual of the gas in the Herbig disks. Debris disks Disks and planet formation 2020-03-15T12:07:55.000
215 2019.1.01365.S 7 Is the IMF top-heavy in an intensely star-forming disk at z=2.6? The ratio of the intensity of the CO isotopologues 13CO/C18O is sensitive to the shape of the stellar initial mass (IMF) function, since the relative abundance of 13C/18O in the ISM is driven by the ratio of high-to-low mass stars. Determining whether a universal IMF can be applied even in the most vigorously star-forming galaxies in the early Universe is a fundamental question of galaxy evolution. We will map the 13CO/C18O ratio in the extraordinarily bright lensed submm galaxy 9io9 at z=2.554. We will determine whether 9io9 follows the trend seen in other IR-luminous starburst systems, with suppressed 13CO/C18O, hinting at a top-heavy IMF. Moreover, we will search for variations in the isotopologue ratio across the source, where gravitational lensing provides access to sub-kpc physical scales in the z=2.554 source plane. We will link any variations to the conditions of the ISM to better understand how 13C/18O can be exploited as an IMF tracer and to explore the properties of this remarkable galaxy in more detail. Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2021-03-10T07:15:58.000
216 2016.2.00014.S 186 ALMA Observations of the Most Massive Galaxy Clusters at z > 1 MaDCoWS is a comprehensive program to detect and characterize the most massive galaxy clusters in the universe at z ~ 1 and above, and is the only all-sky survey sensitive to galaxy clusters at this epoch. The cluster sample resulting from the overall program is designed to be optimal for (1) unbiased calibration of scaling relations for cluster mass estimation techniques (e.g. X-ray, SZ, and weak lensing), (2) identification of extreme mass sources that can be used for cosmological studies such as the f_gas test and measurements of primordial non-Gaussianity, (3) strong lensing studies of cluster concentrations and central mass distributions, as well as identifying lensed high-z targets for ALMA and JWST studies of galaxy formation and reionization, and (4) investigations of the evolution of massive galaxies in the most overdense environments close to their epoch of star formation and mass assembly. Here we propose ALMA ACA observations of 10 of the richest galaxies clusters at z > 1 visible from Chajnantor. With accurate ALMA-measured Sunyaev-Zel'dovich (SZ) masses, this will establish a legacy sample of the most massive (M_vir ~ 10^{15} M_sun) clusters in existence at z > 1. Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters Cosmology 2018-09-06T04:08:15.000
217 2017.1.00287.S 358 Validating the L850-MH2 calibration with Herschel-ATLAS galaxies up to z~0.4 (resubmission) Disentangling the physical processes contributing to the decline in the cosmic star formation rate requires the measurement of the interstellar gas content of galaxies out to high redshift, but CO line observations are difficult and time-consuming. The development of a calibration between the dust continuum luminosity at 350 GHz (lambda = 850um) and the molecular gas content provides a more efficient method to infer the gas mass of high redshift galaxies, yet current measurements of the Lv850/MH2 ratio rely on small galaxy samples. How this ratio varies with other galaxy properties remains unknown. We thus propose to use 3.9 hrs of ALMA Band-6 and Band-7 to observe the dust continuum at 350 GHz to an rms of 0.2 mJy/beam, simultaneously tracing the CO(J=3-2) line at 346 GHz, for 34 galaxies selected from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). With this large sample, we will (i) confirm the Lv850/MH2 ratio found in previous studies, (ii) identify any physical properties affecting the shape or scatter in the calibration, and (iii) provide to the community a robust calibration to apply to higher redshift observations. Resubmission of proposal 2016.1.00994.S. Spiral galaxies Local Universe 2019-05-11T20:12:26.000
218 2018.1.01669.S 17 The [CI] lines as dynamical tracers: rotation, outflow, and heating mechanisms in a massive AGN-host starburst at z=2.6 In Cycle 2 we detected molecular gas in the AGN-host starburst galaxy PKS 0529-549 at z=2.6, using the [CI](2-1) line. The [CI] emission is consistent with a rotating disk: 3D models give a strikingly high Vrot/sigma=10, similar to local galaxy disks. The spatial resolution of the ALMA data (0.4"x0.3"), however, severely limits the interpretation: we cannot categorically exclude other scenarios like a galaxy merger. Moreover, integral-field spectroscopy from SINFONI shows that PKS 0529-549 has an outflow of ionized gas, aligned with two radio lobes, but this is not evident in the current [CI] data. We propose for follow-up observations of both [CI] lines at 0.1" resolution. This will allow us to unambiguously probe the gas kinematics: we will trace the rotation curve (distribution of baryons and dark matter) and investigate the possible molecular phase of the outflow. The ratio of the two [CI] lines will provide the kinetic temperature of the gas, which will be compared to the dust temperature to study gas heating mechanisms. This program will constrain theoretical models of stellar and AGN feedback and provide key insights in the formation and evolution of massive galaxies. Starburst galaxies, High-z Active Galactic Nuclei (AGN) Active galaxies 2021-01-02T17:54:10.000
219 2015.1.00934.S 37 Investigating molecular gas in disks around young Brown Dwarfs with ALMA We propose to observe with ALMA the three disks around young very low mass stars and brown dwarfs which have a previous detection of molecular CO. With the proposed high sensitivity, angular resolution and spectral resolution, we will study the gas kinematics and spatial extent with unprecedented details for disks around these very low mass objects. From the gas kinematics we will obtain dynamical estimates for the stellar/sub-stellar mass, thus providing crucial tests for evolutionary models of these objects and for all studies which are based on this fundamental parameter. We will also measure the radius of the disk in gas. This will be compared to the radius in dust obtained for these disks by our previous ALMA observations. The comparison of them will allow us to investigate radial migration of solids in the regime of low disk masses and temperatures, and test the predictions of models of solids evolution in protoplanetary disks. Disks around low-mass stars Disks and planet formation 2017-10-20T11:17:00.000
220 2019.1.01741.S 22 Abundance vs. IMF -- Studying CO isotopologues at z=2-3 We propose to observe three gravitationally lensed dusty starburst galaxies at z=2-3 with ALMA at 3 mm to measure their 13C16O and 12C18O fluxes and column densities. Elevated ratios of C18O/13CO have recently been presented as evidence of a top-heavy IMF at z=2-3. However, both isotopologues are also commonly used as abundance tracers at low redshift, making their interpretation difficult. We will combine these ALMA measurements with our existing IRAM 12CO and [CI] data to meaure line ratios of 13CO/C18O, 13CO/12CO, and 13CO/[CI] and column densities to distinguish between these scenarios. Each result would be interesting, e.g., finding evidence of changes in abundance would have important ramifications for the on-going discussion about the CO-to-H2 conversion factor. We will use our published multi-line CO LVG modeling and [CI] 1-0 and 2-1 fluxes to constrain the gas conditions as well as possible at z=2-3, and combine these mesasurements with similar IRAM/NOEMA data of brighter, Northern sources, to increase the total number of such observations in the literature from 3 to 12 starbursts, a reasonable sample size for such fundamental astrophysical quantities. Starburst galaxies Active galaxies 2022-05-19T13:56:44.000
221 2021.A.00013.S 33 ALMA Observations of the DART Mission: Revealing Composition of the Impact Ejecta and the Interior of S-Type Asteroids We propose ALMA Cycle 8 DDT observations of ejecta from the DART mission. The DART impact will afford an unprecedented opportunity to remotely characterize the interior composition of an asteroid via high-resolution molecular spectroscopy of the ejecta, excavating relatively unprocessed interior material in the first mission of its kind. Such detailed measurements of interior asteroid composition are ordinarily impossible without exceedingly rare rendezvous missions. Our objectives are to quantify the abundances, distributions, and kinematics of silicate and sulfur compounds that will be liberated from the interior by the impact at high spatial and spectral resolution, thereby addressing key questions regarding the presence of sulfur-bearing species in asteroid regolith. Simultaneous continuum observations will provide the first measure of Didymos' emissivity, revealing highly complementary surface composition information for comparison with the ejecta. These data will yield exceptional insights into asteroid composition to inform our understanding of the terrestrial planet region of the protosolar disk, and can only be measured with the high sensitivity and resolution of ALMA. Solar system - Asteroids Solar system 2023-04-25T22:18:30.000
222 2018.1.00717.S 13 High angular resolution molecular and dust images of Supernova 1987A Supernova (SN) 1987A is a unique SN, which modern telescopes can spatially resolve at wavelengths ranging from X-ray to radio. Its time evolution has been monitored over 30 years, revealing how a SN has transformed into a SN remnant in remarkable detail. For the cycle 6 program, we request deep high-angular resolution images of SN 1987A in bands 6, 7 & 9, covering SiO 6-5, SiO 7-6, CO 6-5 and dust 450-micron and 850-micron emission. The combination of these images will give temperature and column density maps of dust and SiO. Furthermore, SiO data provide the 3-dimensional velocity map of this molecule. With these images, we will investigate four science cases. (1) probing potential on-going interaction between ejecta dust and reverse shocks, (2) tracing the past dust formation and investigating chemistry operating in the SN ejecta (3) identifying the neutron star and (4) investigating the proper motion of clumps in the ejecta and its cooling. Supernovae (SN) ejecta, Pulsars and neutron stars Stars and stellar evolution 2020-12-27T14:27:11.000
223 2022.1.00986.S 0 B335: a unique test-bed for COMs variability Recently, the Bok globule B335, one of the best-studied protostars in an isolated dense core, brightened in the MIR and in ALMA Band 7 observations. Models indicate an increase in luminosity by a factor of 5-7, likely the result of a mass accretion event. In response, the emission lines from COMs increased strongly. This is the first known example of a hot corino varying in real time. Therefore, we propose to observe B335 to track the evolution of the hot corino. By this observation, we aim to detect changes in COMs emission size, as predicted by models, and to test the freeze-out timescale from theoretical calculations. Also, the relative abundances of COMs may be changing in response to the protostellar luminosity variation, opening windows on the ice composition and how the COMs chemistry responds to the enhanced radiation field. Low-mass star formation, Astrochemistry ISM and star formation 2024-06-12T20:25:34.000
224 2016.1.01293.S 19 The Structure of a Massive, Dusty Galaxy During Reionization We request deep, 0.25"-resolution imaging of a unique dusty galaxy in the Epoch of Reionization (EoR), selected via its millimeter-wavelength dust emission in the 2500-square-degree South Pole Telescope (SPT) survey. Spectroscopically confirmed to lie at z=6.900, SPT0311-58 has a large dust mass and is likely one of the most rapidly star-forming objects in the EoR. Although we see no evidence of AGN activity, this galaxy is most similar to the massive quasar host galaxies of its era. We will use the combination of the 158um CII and 88um OIII fine structure lines to determine how such a massive object has been assembled, to map the distribution of star forming regions, and to identify any signatures of the growing black hole that might be expected to accompany rapid stellar mass growth. Deep CII imaging should reveal accreting and outflowing gas, minor merging partners, and other signatures of early galaxy assembly. These observations will also determine whether this source is gravitationally lensed and allow us to model the lensing geometry. These maps will be the first steps toward understanding the most spectacular galaxy discovered by the SPT. Sub-mm Galaxies (SMG) Galaxy evolution 2018-01-03T20:30:27.000
225 2017.1.00075.S 28 Mapping the hot atmospheres of evolved stars Shocks, convection and stellar activity have a major impact on the circumstellar chemistry and mass loss of evolved AGB stars. Surface and extended atmosphere studies of these stars have so far been limited to the visual to near-infrared wavelength ranges, with limited imaging capabilities, or the marginal resolving power offered at radio wavelengths. Using ALMA long baselines, we have resolved exquisit details of the stellar atmosphere of W Hya and Mira. For W Hya we show numerous hotspots close to the actual stellar photosphere, and a hot gas layer with temperature >5000 K. This firmly proves the existence of a (likely shock-heated) chromosphere that shows stellar activity. Only ALMA can image this activity, as at other wavelengths opacity sources limit our view on the stellar surface. Here we propose to map the stellar disk structure of W Hya and R Leo across three ALMA bands. Such observations are crucial for modeling the structure of AGB atmospheres, as our current results challenge almost all available models that underlie our understanding of AGB mass loss. Asymptotic Giant Branch (AGB) stars Stars and stellar evolution 2018-12-08T17:15:11.000
226 2022.1.00477.S 0 Constraining the water evolution in an embedded disk around HH100 Water is a key molecule that can trace the planet formation process and link it to the history of the Solar System. Yet, we still do not know how it is delivered to planet-forming disks. Previous observations of water vapor toward protostellar systems indicate that its abundance is much lower than expected compared to ice observations. The low abundance can be caused by early planet formation or the physical properties of the protostar. By tracing the history of water during the earliest stages of planet formation, it could potentially serve as a tracer of planet formation in various environments. We propose to detect and characterize the warm water vapor emission from a young planet-forming disk around HH100IRS. Cycle 7 and 8 ALMA observations indicate that water lines are tentatively detected. In addition, the same observations reveal the presence of a Keplerian disk around HH100. This program requests deeper observations to spatially resolve the water emission around the Keplerian disk. It will reveal whether water enters the young disk as ice or vapor during the early stages of planet formation which is still missing in the star and planet formation studies. Astrochemistry ISM and star formation 2024-07-28T13:13:28.000
227 2011.0.00130.S 0 Spectroscopy of a normal star-forming galaxy at z=2 with 300 parsec resolution: physical conditions in the cold ISM at high redshift We propose band 9 observations of [CII] emission and 630 GHz continuum in the lensed galaxy MACS J0451+0006 (J0451). J0451 is a normal L* star-forming galaxy at z=2.01 magnified by a factor of 49x due to gravitational lensing, such that ALMA's resolution (0.8 arcseconds) corresponds to only 300 parsecs in the source plane. Our extensive observations and accurate lensing mass model yield an intrinsic radius 2.5 kpc, stellar mass 1.4x10^10 Msun, star formation rate 18 Msun/yr, far-infrared luminosity 1.6x10^11 Lsun, and metallicity 0.6 Zsun, all typical of L* galaxies at z=2. We now seek to characterize the physical conditions, spatial distribution, and kinematics of the cold ISM via resolved observations of [CII]. Our specific goals are to (1) determine the physical conditions of the cold ISM in a typical z=2 galaxy; (2) determine the mode of star formation (i.e. extended disk vs. compact central starburst) via the distribution and kinematics of [CII]; (3) compare the spatial distribution and kinematics of the cold ISM (traced by [CII]) with the bright star-forming regions (traced by Halpha); and (4) determine whether the enhanced [CII] emission seen in the most extreme, luminous high-redshift galaxies is also characteristic of fainter L* galaxies, and if so, determine the physical origin. Our proposal will provide the first study of the cold ISM in a typical high-redshift galaxy, and the first high-resolution data necessary to determine the mode of star formation. These observations would not be possible without lensing; similar resolution and sensitivity would normally require several days of integration with the completed ALMA array. J0451 therefore presents a unique opportunity to study the cold ISM in a normal high-redshift galaxy with ALMA early science. Gravitational lenses, Galaxy structure & evolution Cosmology 2014-02-19T16:24:00.000
228 2016.1.00389.S 21 Characterizing the Envelope-Disk Transition in the Young Protostellar System HH 111 In star formation, rotationally supported Keplerian disks are expected to form inside flattened collapsing envelopes around the protostars. However, current simulations of magnetized core collapse show that magnetic braking can significantly reduce the angular momentum in the innermost part of the envelopes, potentially preventing such disks from forming in the early phase of star formation. In order to investigate this problem, we have observed the very young Class I system HH 111 in Cycle 1. We indeed detected a substantial loss of angular momentum in the innermost part of the envelope possibly due to magnetic braking. We also found tentative evidence that only a relatively small Keplerian disk of order 100 AU in radius is formed around the central protostar, even though there is significantly more angular momentum on the 1000 AU scale to form a much larger disk. Here, we propose to finish our Cycle-1 project, resolving the structure and kinematics of the innermost part of the envelope and the disk, in order to confirm the Keplerian rotation profile of the disk and to better study the envelope-disk transition. Low-mass star formation ISM and star formation 2017-12-17T02:54:40.000
229 2023.1.00734.S 0 The First Map of the Star Formation in a Galaxy at z>3 The Science Verification observations of the z=3.042 lensed galaxy SDP 81 produced spectacular maps of the ISM with a resolution of ~50 pc, revealing massive clouds of gas in a collapsing disk. The early epoch and the rapid global star-formation rate imply that we are seeing this galaxy during its formation phase. In order to investigate the physical relationship between the ISM and the star formation, we need an independent map of the star-formation rate with a similar resolution. Although there are published star-formation maps for galaxies at z>3, they have all been produced from maps of the ISM by assuming a constant star-formation efficiency and are therefore of no value for investigating star-formation physics (they are essentially scaled maps of the ISM). The only practical method for mapping the star formation in a galaxy at z>3 is to combine ALMA Band-10 observations with ALMA observations in lower bands to map the bolometric dust luminosity. We propose to use this technique to produce the first ever map of the star-formation rate in a z>3 galaxy, which will have a resolution of only 200 pc, the size of a giant molecular cloud association in our galaxy. Sub-mm Galaxies (SMG) Galaxy evolution 2025-01-10T10:43:35.000
230 2017.1.00293.S 19 Characterizing the accretion structures around the HMYSOs in W51 The formation process of the most massive O-type stars is one of the main open issues in star formation. There has not yet been a clear detection of a Keplerian accretion disk reported around an O-type forming star. We recently observed accretion structures on ~1000 AU (0.15", resolution 0.04") scales at 1.1 mm, but these structures are far more disordered than the disks seen around low-mass stars. The presence of outflows indicates that the structures are linked to disks on small scales (<500 AU). However, with existing 1 mm data, ths innermost region is obscured by optically thick dust. We propose to image the accretion structures in three well-known high-mass (>20 solar masses) forming stars massive star-forming complex W51 and address the following questions: (1) What are the kinematics on scales <500 AU, where the dust is optically thick at 1 mm but thin at 3 mm? (2) How much of the continuum emission seen on 300 AU scales is free-free emission from ionized gas? What fraction, if any, of the disk is ionized? Are the outflows from these high-mass protostars ionized? (3) Are there large grains in the accretion flow or around the disk? High-mass star formation ISM and star formation 2019-02-02T09:28:53.000
231 2017.1.01120.S 14 Size ratios in Kuiper Belt Binaries A surprisingly high fraction of the bodies in the Kuiper Belt are in binary or multiple systems. The physical properties of the components in binary systems are essential constraints on possible binary formation mechanisms including co-formation, collisions, rotational breakup, and dynamical capture. Determining the relative size of binary components, their albedos, and densities can help to characterize formation and evolutionary processes of the outer Solar System. Utilizing the sensitivity and resolution of ALMA, we will obtain thermal images of four binary Kuiper Belt Objects. For each system, we will obtain the first resolved measurements of the two binary components at thermal wavelengths, allowing us to independently derive the size and albedo of each component of a system using the radiometric method. These results will determine the diameter ratio and make the first measurement capable of detecting albedo differences in these four systems. Improved diameter measurements will be used to derive more accurate densities using the system mass determined from the binary orbit. Solar system - Trans-Neptunian Objects (TNOs) Solar system 2019-03-02T18:33:45.000
232 2013.1.00857.S 30 The Density (and Destiny) of the Circumnuclear Disk The innermost concentration of molecular gas in our Galaxy is the Circumnuclear Disk (CND), a ring of gas and dust at a radius of ~1.5 pc from the central supermassive black hole. Depending upon the mass of this gas reservoir, the fate of the CND (whether it will it form stars, or eventually accrete on the black hole) will have a substantial impact on the evolution of the central parsec of our Galaxy. Its fate depends upon its density: gas clumps with densities > 10^7 cm^-3 are stable, and can collapse and form stars, whereas unstable clumps should quickly be sheared apart and eventually accrete onto the black hole. We propose to use the resolution and sensitivity of Cycle 2 ALMA to conduct a robust probe of gas density on the scales of individual clumps (1", or 0.04 pc) via simultaneous excitation analyses of multiple tracers and the inclusion of radiative excitation. Ultimately, this study will yield the authoritative values for the CND mass and density, quantities which vary in recent literature by 3-4 orders of magnitude, and will indicate the amount of gas present in the central parsecs, and whether it will feed the central black hole or contribute to a nuclear starburst. Starbursts, star formation, Galactic centres/nuclei Active galaxies 2016-03-30T14:13:55.000
233 2015.1.00126.S 17 Submillimeter nature of a putative molecular torus in the type-1 low-luminosity AGN of NGC 1097 The detailed nature of a dusty molecular torus, which is the heart of the unification scheme of active galactic nuclei (AGNs), is still a matter of debate, despite the more than decades-long modeling effort. Here, we propose to observe the CO(3-2) line emission towards the central region of a nearby type-1 low-luminosity AGN, NGC 1097, at 80 mas (5.6 pc) resolution. The 860 micron continuum and HCO+(4-3) line emission will also be detected. With this unprecedented high resolution and sensitivity, we will resolve the innermost r < 20 pc region, where previous observations suggest the presence of a geometrically thick molecular disk. The sphere of influence of this AGN (~ 12 pc) will also be resolved. With these data, we will study the spatial distribution of gas and dust around the AGN and infer the gas kinematics of the region to constrain molecular disk models, as well as to directly estimate the black hole mass. Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei Active galaxies 2018-01-25T05:42:50.000
234 2013.1.00105.S 46 Completing the disk census in Taurus We propose to observe 69 single and multiple young stellar systems in Taurus to answer how protoplanetary disk mass depends on both stellar mass and multiplicity. While previous surveys have demonstrated a clear correlation between stellar and disk mass, most sources below spectral type M3 are undetected and it is not known if the same dependence holds down to the stellar mass limit. Our Cycle 0 observations of wide binaries in Taurus detected disk masses down to 10-4 MSun and revealed a range of disk mass distributions. ALMA’s unmatched combination of sensitivity and resolution enables us to observe a complete sample to tackle this issue; these systems will be observed at a sensitivity level over 10 times better than previous large surveys of this region. The sample has been chosen to provide complete coverage of all stars in the disk-only phase by targeting undetected single stars and undetected or unresolved multiple systems. Using these new 1.3mm (Band 6) continuum fluxes as a measure of outer disk mass, combined with the wealth of ancillary data on Taurus, we will be able to establish the influence of stellar mass and multiplicity on the potential for planet formation. Disks around low-mass stars Disks and planet formation 2016-11-19T20:28:26.000
235 2013.1.00814.S 23 Probing the Formation of Nuclear Stellar Cusps We propose observations with ALMA to spectroscopically map the molecular gas and dust that is associated with the build up of nuclear cusps in late merger stages of Luminous Infrared Galaxies (LIRGs). Our Hubble Space Telescope (HST) near-IR imaging program of the GOALS survey has recently spatially resolved the nuclear stellar structure in 88 LIRGs and revealed an increasing fraction of strong cusps towards late merger stages. ALMA will spatially resolve the morphology of the gas components of the cusp on a scale comparable to that of the HST. We have selected the five strongest cusp galaxies in our sample and a well matched comparison sample of five pre-cusp galaxies. The aim of this proposal is to unveil the molecular gas morphology (CO) and mechanisms associated with cusp formation and to accurately measure how much gas mass is involved in the build-up of stellar cusps. The decomposition of the gas kinematics will provide an unprecedented spatial measurement of the mass-to-light ratio of nuclear cusps and cores, providing a crucial test whether the central dark matter distribution is affected by the cusp/core evolution as seen in the stellar component or not. Galactic centres/nuclei, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Active galaxies 2016-10-02T23:29:48.000
236 2016.1.00085.S 311 Protostellar Multiplicity in Isolation Multiple star systems are a common outcome of star formation. While the multiplicity frequency and separation distribution are well-characterized for field stars, theoretical studies predict that the majority of multiple systems form very early in the protostellar phase and undergo significant and rapid dynamical evolution. Thus knowledge of the intrinsic multiplicity fraction and separation distribution before modification via dynamical evolution requires studying the youngest objects: protostars still embedded in and accreting from their parent cores. Recent surveys have made great progress in characterizing protostellar multiplicity in clustered environments but have left unanswered a key question: does the formation of multiple systems depend on environment? Here we propose an ALMA band 6 multiplicity survey of 31 truly isolated protostellar cores down to approximately 25 AU resolution in order to measure the protostellar multiplicity fraction and separation distribution in isolated globules and determine the effects of environment on fragmentation. Low-mass star formation ISM and star formation 2018-09-11T00:14:31.000
237 2016.1.01539.S 15 Distribution of dense molecular gas in the active center of Lupus3 The critical processes on the star formation process occur on spatial scales ranging from 0.05 pc to 100 AU, when the gas moves from dense cloud core onto protostellar envelope scales. These scales determine the mass reservoir of the forming stars, and the number of companions in multiple systems. Lupus is among the nearest low mass star forming clouds in the southern hemisphere, and the central core of Lupus 3 has the right angular size and protostellar density and variety to allow us to measure the gas processes on scales from cores to envelopes using the ACA as a stand alone instrument in Band 6. We will observe CO, 13CO, C18O, H2CO, and DCN lines in Band 6 to sample the large scale gas in the filaments (CO 2-1), high velocity outflow emission (CO 2-1 plus 13CO and C18O for opacity correction), structure of the protostellar envelope (13CO and C18O), and high density (DCN) and temperature (H2CO) gas and dust (in the continuum). Thus, we will obtain a comprehensive dynamical state of Lupus 3 to investigate its internal fragmentation and feedback processes. Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2019-07-26T00:00:00.000
238 2023.1.01358.S 0 Deciphering the large- and small-scale B-field morphology in a massive star-forming clump Determining the morphology of the magnetic field in high-mass star-forming regions is crucial for understanding their role and importance in the formation of massive stars. G31.41+0.31 is a well-known example of an OB-cluster forming clump with an hourglass magnetic field in the inner 0.1 pc, as resolved by high-resolution (0.2-arcsecond) 0.89-1.3 mm dust polarization maps. However, a recent 2-arcsecond resolution 7 mm polarization map revealed that the large-scale (0.4 pc) magnetic field is rather uniform and perpendicular to the axis of the small-scale hourglass field. We hypothesize that this discrepancy is caused by the misinterpretation of the 0.89-1.3 mm map due to missing short-spacing data or that the 0.89-1.3 mm and 7 mm maps trace different polarization mechanisms. To investigate this discrepancy, we propose a 0.2-arcsecond resolution, optically thin, full polarization observation at 2.1 mm (band 4) that could recover the cloud up to 20" (~0.4 pc). We aim to discern how the large-scale uniform B-field is connected to the small-scaled hourglass field and clear up the polarization mechanism(s) traced in previous studies. High-mass star formation ISM and star formation 3000-01-01T00:00:00.000
239 2013.1.00099.S 25 Dense Gas Thermometry of Starburst Galaxies A characterization of the physical properties of the dense gas within the interstellar medium of starburst galaxies is critical to our understanding of their evolution. Many of the molecular tracers used to characterize the dense gas in star-forming galaxies suffer from a coupled degenerate sensitivity to the kinetic temperature and volume density. A molecular tracer which can decouple individual physical conditions is required. Results from a survey of a sample of active star-forming galaxies has shown that Formaldehyde (H2CO) is a reliable and accurate density probe for extragalactic environments where the kinetic temperature is known. Ammonia (NH3) is a traditional probe of the kinetic temperature in dense gas environments, but its utility requires an assumption of cospatiality between dense gas tracers is required. Using the unique sensitivities to kinetic temperature afforded by the excitation characteristics of several transitions of H2CO, we propose to continue our characterization of the dense gas in galaxies exhibiting starbursts by imaging the gas kinetic temperature in a representative pilot sample of three starburst galaxies: Arp220, NGC253, and NGC4945. Starbursts, star formation, Merging and interacting galaxies Active galaxies 2016-02-09T15:31:44.000
240 2012.1.00469.S 3 Probing the effect of ionization on the circumstellar structure of the massive embedded star AFGL 4176 Using the ALMA Cycle 1 extended configuration in band 6, we prepose to observe AFGL4176, a highly luminous embedded massive star for which we have already mid-infrared interferometric and ATCA 20-24GHz observations to hand, to determine the impact ionizing radiation can have on the surrounding geometry, kinematics and physical properties of the accreting material. Our proposed observations centered at ~240 and 255 GHz will trace molecular and ionized gas, as well as dust, in the same observation, using observations of CH3CN 13(k)-12(k), H29alpha and dust continuum respectively. These observations will also allow us for the first time to combine and model interferometric observations from two state-of-the-art telescopes in different wavelength regimes: ALMA and VLT. By combining and modelling the results of our proposed ALMA observations with our MIDI mid-IR interferometric data, we will trace the geometry continuously on scales spanning hundreds to tens of thousands of AU. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2015-09-12T12:41:27.000
241 2018.1.00119.S 30 Constraining the Interstellar Medium Properties of the Most Luminous Galaxy Known At a redshift of 4.601 and with a luminosity of Lbol = 3.5 x 10^14 Lsun, WISE J22460526 (W2246 hereafter) is the most luminous galaxy detected to date. Cycle 2 ALMA observations of the [CII]158um emission line have revealed a strikingly uniform and highly turbulent interstellar medium (ISM) that is being blown away from the host galaxy isotropically, likely by the energetic feedback from central AGN. Recent cycle 4 observations revealed that the gas reservoir at the center of W2246 is being fed by a multiple merger process, and cycle 5 [NII] observations point to an extremely dense ionized medium. However, there are many ISM properties of this outstanding source that are still unknown. Here we propose to obtain ALMA multi-band observations of W2246 in the [CI]607um, [CI]370um, [OI]145um, [OIII]88um and [OI]63um emission lines, at an angular resolution similar to that of our [CII] and [NII] data, ~0.3". The goal of this project is to use this suite of far-infrared lines to characterize the properties of the gas in a galaxy that represents the ultimate laboratory for studying and model the ISM physics and kinematics under strong feedback at high redshift. High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution Active galaxies 2022-10-14T23:52:53.000
242 2016.1.01599.S 15 Nature and origin of the candidate pre-brown dwarf core OphB-11 The origin of brown dwarfs (BDs) is an important astrophysical mystery because its solution can also shed light on how a broad range of objects, from typical stars to giant planets, are formed and gain their masses. Using the IRAM Plateau de Bure interferometer (PdBI) at 3.2 mm, we identified a good example of a pre-brown dwarf core (Oph B-11), a self-gravitating starless condensation of gas and dust in the brown-dwarf mass regime (André et al. 2012, Science). Our PdBI result tends to support models according to which BDs form in a similar manner to normal stars, from the direct collapse of a prestellar core. Because the Oph B-11 core is weak and difficult to observe from IRAM, however, its basic properties (e.g. radius, mass, density) remain uncertain and its formation mechanism is not well understood. We propose ALMA/ACA mosacing observations in Bands 6 of Oph B-11 and its immediate vicinity in order to obtain robust measurements of its size, structure, mass, and test the hypothesis that the pre-BD core was formed as a result of low-velocity shock compression. Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2019-05-22T00:00:00.000
243 2018.1.00704.S 50 Dissecting a high-mass star-forming dense clump in the center of a hub-filament system The processes driving high-mass star formation (HMSF) are under intense debate. Central questions are related to the mass accumulation process from clump scales (>0.1 pc) to protostars and relative birth order of high vs. low-mass stars. Sensitive, high-resolution observations are crucial to disentangle between the various proposed scenarios. G22C1 is a globally collapsing massive clump at the center of a hub-filament system. A high-mass star-forming hot core (SMA1) has been detected with SMA observations. Multipolar outflows demonstrate the presence of substructures and compact star formation. On larger scales, filamentary inflows are feeding the globally collapsing massive clump G22C1 while SMA1 exhibits spectral infall signatures. In short, G22C1 is an ideal target for studying the mass accumulation in HMSF. We propose to map the entire G22C1 clump using ALMA/Band 7. Simultaneous observations of HCO+/H13CO+ (4-3), CO (3-2), SiO (8-7) and two 1.8 GHz windows will enable us to (a) observe the internal structure of SMA1 and companion low-mass cores around SMA1, (b) study the kinematics of embedded dense cores, and (c) determine the relative birth order of high and low-mass stars. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2020-08-15T20:27:47.000
244 2018.1.01616.S 41 Resolving the dust emission in heavily obscured, hyper-luminous quasars at z ~ 1.5 We propose a detailed ALMA study of four sources from a unique sample of 156 distant (0.5 < z < 3) heavily obscured, hyper luminous quasars (QSRs) which have sub-galactic, young radio jets. These four sources show interesting (sub)arcsec structure in 10 GHz JVLA snapshot images. The key observational goals are to spatially resolve the submm emission and look for CO line emission. Our ALMA Cycle-0 345 GHz snapshot imaging revealed all of them to be unresolved at 1" scale. This high-resolution study follows up the brightest targets with known redshifts. The setups are optimized to map the morphology of the 345 GHz (band-7) continuum on 1-2.4 kpc scales: similar to the radio jet structures and cores. The overall science goal of our multi-telescope program is to study the earliest stages in the life-cycle of luminous AGN. The key feature under investigation for this proposal is the onset of the various feedback mechanisms including, the contribution of radio jets to ISM purging and star formation quenching. In particular, we wish to study the structure and dynamics of the ISM in detail through kpc resolution imaging of the dust continuum and CO line emission. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 2021-01-22T15:26:08.000
245 2023.1.00882.S 0 Physics of the cold circumgalactic medium in the Spiderweb: new high-z science with ALMA Band-1 ALMA Band-1 will open exciting new science areas, one of which is to study how cold molecular gas on large scales drives the evolution of distant galaxies. ALMA's ultra-compact configurations are unique for imaging low-surface-brightness emission from molecular gas in the circumgalactic medium (CGM). We will use Band-1 to image CO(1-0) from widespread, cold molecular gas across the halo of the massive Spiderweb Galaxy (z=2). For the first time, we will study the physical processes of molecular gas locally within the CGM (excitation, carbon abundance, star formation, and AGN feedback), by comparing the CO(1-0) to CO(4-3) and [CI] (ALMA Band-4), diffuse starlight (HST), and the radio source (VLA). In addition, utilizing the large field-of-view of Band-1, we will characterize large molecular gas reservoirs in 19 CO-detected protocluster galaxies in the Spiderweb field, some of which already revealed molecular disks or tidal debris on tens of kpc scales. Our deep CO(1-0) imaging of spectacular molecular reservoirs around the Spiderweb and neighboring galaxies will highlight new Band-1 science, and showcase ALMA's role in studying the critical role of the cold CGM in galaxy evolution. Galaxy structure & evolution Galaxy evolution 2025-04-16T17:03:27.000
246 2012.1.00240.S 6 Mapping Star Formation and Gas Dynamics in Luminous Quasar Host Galaxies at z~6 Understanding the growth of the first supermassive black holes (SMBHs) and their host galaxies is one of the primary goals of modern galaxy evolution studies. We propose to make spatially resolved observations of the [C II] 158 micron fine structure line and dust continuum emission in three z~6 quasars that are detected in our Cycle 0 project, to trace the distribution of star formation and measure the kinematics of the host galaxy. Strong FIR dust continuum, molecular CO line emission, and massive star formation have been discovered in about 30% of the quasars known at z~6. These FIR luminous quasars at z~6 provide the brightest sample to study galaxy formation and SMBH-galaxy coevolution within 1 Gyr of the Big Bang. Deep imaging of the [C II] line emission from the brightest source, SDSS J1148+5251 at z=6.42, reveals a peak star formation rate surface density of 1000 Msun/yr over the central few kpc region, together with strong gas outflow driven by AGN feedback. We have an ALMA Cycle 0 project to search for [C II] line emission from a sample of five FIR-luminous quasars at z~6. We have data in hand for three of them and all are strongly detected. The line velocity maps of two of them show tantalizing hints of velocity gradients which may suggest emission from a rotating starburst disk; the third object shows a broader [C II] line compare to previous CO observations. High S/N and resolution observations are required to confirm and fully understand these intriguing trends. The excellent capability of ALMA in Cycle 1 now open a unique opportunity to resolve the [C II] line, dust continuum emission, and star forming activity, on kpc scale (0.2" resolution) from these most distant starburst quasar host galaxies. We here propose to extend the [CII]/dust continuum imaging to all the three new Cycle 0 detections at z~6 with ALMA in C32-6 to measure the star formation rate surface density and constrain the general bulge building process in these earliest quasar host galaxies. Moreover, the resolved velocity field of the [C II] line emission will trace the kinetic properties of the atomic gas in the starburst nuclear region, measure the circular velocity and dynamical mass of the stellar bulge, and address if the gas outflows found in J1148+5251 are common in all these young quasar host galaxies at the earliest epoch. High-z Active Galactic Nuclei (AGN) Active galaxies 2016-11-06T01:35:11.000
247 2018.A.00026.S 46 Mapping CO Emission in eta Carinae near Periastron Passage with ALMA Numerous molecules are formed in eta Car's nebula despite the intense ionizing radiation field from the hot binary at the center. The shielded features may be a result of a stellar merger following an eruption by a single massive star. The present-day binary from the hypothetical initial triple-star has an eccentric 5.54-year orbit, currently at phase 0.82; periastron occurs in 12 months. We propose to observe CO (2-1) and (1-0) and H30-alpha at 0.2"-2.0" resolution in phase < 0.9 (a ~6 month window), just prior to a sharp drop in X-ray/UV field intensity as the hot companion dives into the primary's dense wind. This will allow us to physically characterize the shielding structures associated with at least 7 known kinematic components during the ionization high state, complemented by our single-dish ground-, airborne, and space-based observations, and upcoming HST, VLTI, and Chandra observations. The DDT path is motivated by our extended team's new publication describing the radiation field's cyclic evolution and nebula response times, and will reward us with insight into eta Car's role in a broader paradigm for LBV activity related to stellar mergers. Evolved stars - Shaping/physical structure Stars and stellar evolution 2019-11-06T21:28:16.000
248 2022.1.01401.S 20 A new ALMA window on Cosmic Dawn: pilot at z~10 Searches in CO or C+ for ultra-high-redshift galaxy candidates have consistently failed, possibly due to underabunbdance of C at the earliest epochs, while [OIII] has shown promise. The pioneering and unexpected detection of water in absorption against the CMB in the z=6.34 galaxy HFLS3 strongly suggests that the CMB will be found to pump other transitions depending on redshift. We have therfore conducted a systematic search in the ALMA archive for other species in absorption in ultra-high-redshift galaxies, and detected a P Cygni line in the galaxy GS-z10-1, which we identify as either the OH+ 909 GHz or 972 GHz transition. The positive flux significant at 5.4 sigma and the absorption at -3.0 sigma, and the redshift is consistent with the photometric estimate of z_phot = 9.9 +/- 0.5. Here we request urgent follow-up redshift confirmation through the bright [OIII] 88micron line, which is redshifted to ALMA Band 7. This will be a highly effective proof of concept for redshift determination in ultra-high-redshift galaxies using absorption lines in the low frequency end of Band 3 and in future in Band 2, and will open up the >3mm windows for exploring Cosmic Dawn. Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) Galaxy evolution 2024-01-10T12:12:27.000
249 2017.1.01618.S 102 Do there exist mini-SMGs at cosmic noon? We propose band-6 observations of six low-mass (Ms~10^9Msun) but red (UV slope >= -1.2) star-forming galaxies primarily selected from our large spectroscopic sample of z = 2.2 Lyman alpha emitters. SED fitting to their rest-frame UV to NIR photometry gives as high IRX=L(IR)/L(UV)~10 as of submm galaxies (SMGs), placing them well above the average IRX-Ms relation. In the literature, only one such miniature SMGs has been likely identified at cosmic noon because of faint dust emission. In this proposal, we will measure L(IR) for the six objects from dust continuum and derive dust-obscured star formation rates, SFR(IR), and dust masses, Md. High SFR(IR) and Md, if obtained as expected, will demonstrate that even low-mass galaxies, although not majority, experience dusty starburst, urging dust formation models to find a way to very efficient dust production in low-mass galaxies, which appears to be a more serious problem than the dust budget crisis of SMGs. Lyman Alpha Emitters/Blobs (LAE/LAB), Starburst galaxies Galaxy evolution 2019-05-18T09:35:16.000
250 2015.1.00408.S 14 The G16.59-0.051 Disk+Jet System: A Bridge between Low- and High-Mass Star Formation Comparing the few disk+jet systems detected around B-type YSOs with those in low-mass YSOs is fundamental to test if the process of mass accretion/ejection does simply scale with the YSO mass and should help judging about the existence of such ordered structures in the extreme environmental conditions of an O-type star. We have discovered a clear example of a B-type YSO surrounded by a disk+jet system in the HMSFR G16.59-0.051. A small (size~0.3") rotating structure (the "disk") is traced both by the 3-D velocities of the 6.7 GHz methanol masers and the LSR velocities of the NH3(2,2) line emission. Our recent JVLA A-array observations (at 6, 2 and 1.3 cm) have revealed an extended (3"-4") 6 cm radio jet (emerging from the disk and directed close to the maser rotation axis), and compact 1.3~cm, free-free emission placed near the centre of the maser distribution. The stellar mass implied by the observed luminosity (13 M_sun) agrees well with the equilibrium mass (12 M_sun) of the maser disk. We propose ALMA observations of typical "disk" and "molecular outflow" tracers, employing the C36-5 configuration of the array and Band 6. High-mass star formation ISM and star formation 2018-02-16T10:11:22.000
251 2017.1.01355.L 1619 ALMA-IMF: ALMA transforms our view of the origin of stellar masses Studying massive protoclusters is an absolute requirement for investigating the origin of the IMF in the typical, yet extreme environments where massive stars are born. Recent ALMA imaging of a young massive protocluster revealed the first definitive case of a core mass function (CMF) whose shape is different from the IMF. In contrast, the CMF shape in more evolved but still embedded massive clusters more closely resembles the IMF. This raises the intriguing possibility of CMF evolution with time. We aim to determine when and by which physical processes the CMF of massive protoclusters is reconciled with the canonical IMF. We propose to investigate the CMF evolution of massive protoclusters with the 15 most massive pc^2 clouds at d < 6 kpc. We will focus on 1) investigating the distribution of 0.5-200 Msun cores at 1~mm and 3~mm at the 2000~AU core size; 2) characterizing the core mass evolution through gas inflows toward individual cores and gas outflows driven by protostars; and 3) compare massive protocluster CMFs to the IMF and determine which variables (such as inflows, outflows, or forming filaments) might be correlated with CMF evolution toward the IMF shape. High-mass star formation, Low-mass star formation ISM and star formation 2019-10-27T00:00:00.000
252 2017.1.00983.S 163 Quantifying the Feedback Potential of Young Massive Protoclusters In a series of radio and infrared surveys, we have identified a sample of 20 massive protoclusters existing in a specific evolutionary state in which outflows dominate their infrared appearance. Our SMA millimeter data at 3" resolution reveal high velocity CO emission (up to +-80 km/s) with complex morphology indicative of multiple actively-accreting protostars. We propose to test the theoretical idea that the combined outflow feedback is enough to maintain turbulence but not enough to disrupt the parental gas reservoir, thereby allowing star formation to proceed at a regulated rate. We will image 10 protoclusters on scales of 0.8"-20" for which we also have SOFIA mid-IR imaging observations. Using a set of outflow and hot core tracers, we will resolve individual outflows, identify their driving sources, and compute their momentum and energies. The combination of SOFIA and ALMA continuum imaging will enable measurements of the individual protostellar luminosities thereby allowing an accurate estimate of the contribution of radiative feedback. We will compare these results with the gravitational energy of the gas and the dynamical mass of the cluster. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2019-06-29T19:36:49.000
253 2022.1.01384.S 10 Probing the origins of [CII] emission in the Epoch of Reionization We propose band 5 observations to measure [NII]205um emission lines from three [CII] luminous galaxies in the epoch of reionization (at z=6.5-7.7). These galaxies were recently spectroscopically confirmed by their luminous [CII]158um emission lines as a part of an ALMA observing campaign. While the recent [CII]158um line observation provided a large number of detections, the detailed origins of [CII] lines are still elusive. Despite the uncertainty, [CII]158um emission lines are used as tracers of several galaxy properties (e.g., star formation rates and neutral gas mass). To accurately understand the origins of the [CII] emission line and to understand the conditions of ionized and photodissociation gas, multiple emission line observations are needed. By the proposed observations of [NII] 205um we will achieve the following: (1) investigate whether PDR or HII regions are the dominant source of [CII] line, (2) model ionized and photodissociation gas by combining existing and incoming observations. These observation provide a showcase of emission line from ionized gas in the EoR, in conjunction with the scheduled Cycle-1 JWST observations. Lyman Break Galaxies (LBG), Galaxy structure & evolution Galaxy evolution 2024-04-25T04:36:22.000
254 2023.1.00040.S 0 Angular momentum in hub-filament systems: Deciphering signatures of rotation and global collapse. High-angular resolution observations of high-mass disk and toroid candidates suggest that their angular momentum is up to 2 orders of magnitude higher than that of low-mass disks. IRAM 30-m N2H+ observations of one of these toroids, G31.41+0.31, have revealed that the kinematics at large cloud scales (10^5 au) and small toroid scales (a few 10^3 au) could be tightly connected, and that the specific angular momentum distribution for high-mass YSOs might be fitted with a single power-law from cloud to circumstellar scales. We propose to map with ALMA at 3.7" resolution and with a mosaic of 75 pointings the entire G31.41+0.31 cloud in N2H+(1-0) at 93.174 GHz. The goal is twofold: i) to map the velocity field of all the IR-dark filaments to search for velocity gradients along the filaments that could confirm that matter is flowing toward the central hub/core, and ii) to trace the kinematics of the gas at intermediate scales, filling the gap between 10^5 au and a few ~1000 au, to estimate the radial distribution of specific angular momentum over the cloud and determine whether this quantity decreases with radius in a manner similar to the trend found for low-mass star-forming regions. High-mass star formation ISM and star formation 3000-01-01T00:00:00.000
255 2013.1.00812.S 10 Hiding in the Shadow of Giants: Low mass cores in massive (proto)clusters Most stars form in clusters, yet basic aspects of how this occurs remain unknown, including the relative birth order of high and low mass stars. In clump-scale "competitive accretion"-type models, massive stars and their surrounding cluster of lower mass stars form simultaneously. Thus a key, testable prediction of these models is that centrally condensed low-mass cores should exist within the accretion reservoir of a forming massive star. Using the unprecedented sensitivity and dynamic range of ALMA, we propose to test these models by searching for the 1.0 mm continuum emission from the low-mass core population associated with two young massive (proto)clusters that show strong evidence for recent shocks, active outflows, and hence ongoing accretion (both GLIMPSE Extended Green Objects, EGOs). By imaging the full extent of the associated (sub)mm clumps (~0.8 pc diameter), we will characterize the entire low-mass core population of our target clusters, down to 0.1 Msun. To measure the kinematics of these cores, we also target the N2H+(3-2) line. High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2016-08-09T11:17:01.000
256 2022.1.00788.S 0 A zoom-in view on the archetypal disk at z > 4. Is it really a disk? High-resolution dynamical studies of star-forming galaxies up to z ~ 4 have been crucial to gaining insights into the processes driving the growth of galaxies across cosmic time. Understanding the dynamical properties of typical galaxies at z > 4 is the next step to pushing our understanding into the early phases of structure assembly. We propose to gather 1 kpc-resolution [CII] line data of a main-sequence galaxy at z = 5.5, HZ4. Generally considered as the archetypal high-z rotating disk, the application of a novel kinematic classification method on ALMA archive data of HZ4 shows that it is, instead, a merger. Thanks to the requested data, we will solve this puzzle and characterize its dynamical state robustly with morphological and kinematic analysis. This will allow us to gain insight into the assembly of early galaxies. The combination of multi-wavelength observations on matched spatial scales will provide the most detailed view of 1 kpc-scales of a typical galaxy at z = 5.5, investigating the dark matter content and turbulent structure of its interstellar medium. Lyman Break Galaxies (LBG), Galaxy structure & evolution Galaxy evolution 2024-10-25T20:45:16.000
257 2022.1.00450.S 0 A systematic Characterization of the Outflows at Ophiuchus Molecular Cloud While essentially all nearby ($<$ 200 pc) star-forming regions (Ophiuchus, Lupus, Chamaeleon, and Taurus) have already been surveyed by ALMA in the continuum, a systematic identification and characterization of their molecular outflows is yet to be done. The Ophiuchus molecular cloud is particularly well suitable for such an study as it contains a large number of embedded sources. Using ALMA archival data available for the entire population of young stellar objects in the cloud, we have identified a total of 20 new molecular outflows associated to Class I to Flat spectrum sources. Here we propose a Band-6 project to characterize the morphology and dynamical parameters of the new identified outflows. This will result in the first systematic demographic study of outflows at high angular resolution in a nearby molecular cloud and associated to Class I to Flat spectrum sources, which will help to put into context the many studies of individual outflows already present in the literature. Outflows, jets and ionized winds ISM and star formation 2024-08-31T18:51:24.000
258 2018.1.00765.S 157 The parsec scale view of the starburst ISM through molecular diagnostics Extreme activities in starburst galaxies have a direct impact in their molecular interstellar medium (ISM). Parsec-scale resolution observations allow for the study of the ISM in starburst galaxies down to young stellar cluster scales. Thanks to its proximity and brightness, the starburst galaxy NGC 253 allows for the most detailed studies of the ISM in an starburst environment using (sub-)millimeter molecular and recombination lines. These lines are an effective probe due to their large penetration depth. Using measurements of a variety of molecular diagnostic and recombination lines, we will study the physical conditions, effects of UV-photons and shocks, excitation conditions, and star formation rates on young star cluster spatial scales. We will perform a spectral scan in Bands 6 & 7 with 0.2 resolution in the central 15 of NGC 253 to cover all transitions of interest. Short spacing information will be provided by the our ongoing project. Our spectral scan will efficiently reveal the highly excited physical conditions, effects of feedback, the evolutionary stages within the central molecular zone in the nearest starburst galaxy NGC 253. Galaxy chemistry, Giant Molecular Clouds (GMC) properties Galaxy evolution 2020-01-17T03:33:26.000
259 2015.1.00341.S 51 Revealing Magnetic Field Structures: IM-mass Cores in OMC-3 Understanding the magnetic field on size scales smaller than a core (<0.05 pc) is crucial to see how the magnetic field is responsible for setting initial conditions of star-formation. We propose polarization and molecular line observations toward candidates of intermediate-mass prestellar and protostellar cores in OMC-3, where is the nearest ideal laboratory for studying the magnetically regulated core-collapse process. Proposed polarization observations will spatially resolve the polarization distribution and we aim to measure the polarization degree down to 200 AU scale for all the targets, and down to 12 AU for the brightest and youngest protostellar source found in OMC-3. Proposed line observations will directly image core internal structures such as pseudo disk, circumstellar disk, and root of the outflow, and reveal their kinematic structures with the same angular resolution obtained for polarization images. The obtained results will be compared and iterated with theoretical models (MHD simulations) optimized specifically for our targets, and finally study how the magnetic field changes with respect to the evolutionary stages of cores. Intermediate-mass star formation ISM and star formation 2018-11-20T00:00:00.000
260 2021.1.01503.S 0 Massive, rapidly quenched galaxies 2 Gyr after the Big Bang. What happened to their ISM? Reconstructing a detailed view of all the possible quenching pathways of massive galaxies is a daunting task. While their stellar component provides a wealth of information, little is yet known of their interstellar medium besides it being insufficient to sustain star formation. Recent efforts to probe the ISM of quiescent galaxies extend only to z=2 and have produced mixed results. Here we propose to investigate the ISM content of a homogeneously-selected sample of 10 spectroscopically confirmed quiescent galaxies at 2.3 < z < 3.2 (the largest in this range). These rapidly quenched, bulge-dominated, compact galaxies are representative of some of the earliest quenching events known to have occurred in the Universe. We request a total of 25.8h of ALMA continuum observations at 1.1mm to obtain a direct constraint on their dust emission, a critical piece of information still lacking at these redshifts. These observations will systematically extend gas fraction evolution studies up to z~3 and down to 5% on individual sources. They will also clarify whether dust obscured star formation has anything to do with post-starburst spectra dominating massive quiescent galaxies at these epochs. Galaxy structure & evolution Galaxy evolution 2025-03-07T16:45:22.000
261 2011.0.00525.S 0 Imaging the Most Luminous Galaxy within z=0.01 We propose high resolution imaging of molecular gas in the most luminous galaxy within z=0.01. Our main targets in the merger NGC 3256 (D=40 Mpc, Lbol=4e11 Lsun) are the double nuclei with a 1 kpc (5") separation and the >1000 km/s-wide high-velocity gas in the central region, which we have previously found and attributed to a massive molecular outflow. We will assess the dynamical and physical properties of the molecular gas in the merger to uncover the interplay between molecular gas and the high luminosity starburst, a key process in the merger-induced galaxy evolution. Our cycle 0 observations of this nearby luminous infrared galaxy (LIRG) will also serve as a pilot study for full-ALMA observations of more distant LIRGs (z ~< 0.1) since the linear resolution and mass sensitivity will be comparable. Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Galaxy evolution 2013-11-26T05:45:00.000
262 2018.1.00248.S 10 Zooming into a Swift/BAT-selected buried AGN of NGC 7172 with a candidate dispersion-dominated thick gaseous disk We propose to conduct 0.1" or 16-pc resolution ALMA Band-6 observations of CO(2-1) at the nucleus of NGC 7172, hosting a "New-type" AGN selected by the Swift/BAT all sky survey. Subsequent X-ray spectroscopy suggests the fractions of scattered soft X-rays w.r.t.the direct emission is only < 0.2%, an order of magnitude smaller than classical type-2 Seyferts (1 - 3%). Furthermore, our recent ~100-pc resolution ALMA observations of CO(2-1) reveal a drastic increase of the velocity dispersion to rotation velocity ratio, sigma/Vrot, a key indicator of the disk thickness, at r<100 pc of NGC 7172. These facts make NGC 7172 a promising target hosting a SMBH embedded by a geometrically thick torus with a very small opening angle. Our primary goal is to test if the CO(2-1) gas disk in NGC 7172 exhibits a high sigma/Vrot ratio beyond unity, which supports the presence of geometrically thick cold molecular material in the central ~10 pc region of a new-type AGN. We will also search for any signature of molecular outflows at r<100pc, to compare with the putative OH outflow by Herschel and ~kpc scale outflow uncovered in the previous ALMA data. Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei Active galaxies 2020-12-18T19:23:14.000
263 2021.1.00637.S 19 A [CII] census in two giant Lyman-alpha blobs at z=3 Extended Lyman-alpha nebulae (so called Lyman-alpha blobs, LABs) provides a benchmark of the presence of plentiful hydrogen on circumgalactic medium (CGM) scales and provides clues to understanding galaxy formation and evolution. One of the most spectacular LABs known to date is LAB1 in the SSA22 proto-cluster at z = 3.1. Recent ALMA observations revealed that the [CII] emission is widely distributed in a central 100 kpc region of LAB1, also showing multiple major-mergers. To expand our understanding from one case study to the more general picture, we here propose to observe [CII]158um emission and dust continuum for two additional LABs in the proto-cluster, LAB2 and LAB8. In conjunction with MUSE Lyman-alpha data, we will uncover the ISM in and around galaxies associated with these two spectacular LABs. Our immediate goals include: (i) to determine the power source of the Lyman-alpha emission; (ii) to uncover the interplay between galaxies and surrounding gas; and (iii) to trace galaxy assembly in LABs. Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) Galaxy evolution 2023-09-23T14:41:23.000
264 2021.1.01628.S 93 85 birds -- 1 stone: The most efficient line survey of SMGs in Bands 3 through 8 The Herschel space observatory mapped more than 1000 sqr. deg. and detected more than half a million sources. Recent redshift searches are enabling full spectroscopic follow up; however, exploiting this with ALMA is challenging, as the large overheads favour deep studies of individual sources. Here, we propose an alternative to targeted single-spectral line surveys. Instead, using ALMA as efficiently as possible, to observe 16 sources in CO, [CI], and H2O, as well as absorption and fine-structure lines together with the dust continuum, each of which are sensitive to different phases of the ISM and galactic phenomena, such as turbulence, obscured AGN, molecular gas mass, gas temperature and star-formation rate. We can do this within 6.5 hours by observing sources within 10 degrees on the sky in quick snapshots that do not require re-calibration, targeting 85 spectral lines in within a single tuning set-up in Bands 3, 4, 5, 6, 7, and 8. We will facilitate future observations by making this method public and widely available within the ALMA (and wider interferometric) community. Sub-mm Galaxies (SMG) Galaxy evolution 2022-12-02T10:24:04.000
265 2021.1.01099.S 14 Revealing the Physical Properties of Fibers in the TMC-1 Filament Filaments sometimes contain velocity-coherent subfilaments called fibers. The origin of fibers remains highly debated. Two schools of thought have been discussed so far. One is that the main filaments form first and they fragment into fibers. Another picture is that the fibers are gathered to form the main filaments. Here we propose ALMA Band-3 mosaic observations toward a nearby filament, TMC-1, containing ~21 fibers. Generally, fibers are expected to have widths of ~ 0.03 pc. The distance to TMC-1 is about 140 pc and thus our proposed observations can resolve the internal structures of the main filament and fibers with unprecedented high spatial resolution, 4" (= 0.003 pc). Then, we aim to constrain the role of the fibers in star formation process, using the velocity and density structures of fibers and the filament. Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2023-12-20T20:06:43.000
266 2016.1.00683.S 133 Black hole mass measurements in the most MASSIVE Galaxies Massive early-type galaxies (ETGs), as the end point of galaxy evolution, are the subject of intense interest. Yet, their complex formation histories remain obscure. In lower-mass objects black holes (BHs) are strongly correlated with properties of the stellar bulge implying co-evolution between the BH and stellar components. The BH mass in massive ETGs, however, does not correlate well with galaxy parameters. The most massive galaxies and their central BHs therefore may have followed different evolutionary paths from their less-massive counterparts. We propose to observe the molecular discs that lie in the heart of four of the most massive molecular gas hosting early-type galaxies in the local universe, in order to estimate their SMBH masses. With these observations we can test the feedback paradigm, constrain the environmental dependance of SMBH-host galaxy relations, provide important cross-checks on SMBH mass measurement techniques and anchor studies of the SMBH - host galaxy relations which use molecular gas. In this way a short investment of ALMA time can help reveal more about the complex formation histories of the most massive galaxies in our universe. Early-type galaxies, Galactic centres/nuclei Galaxy evolution 2018-11-03T19:18:37.000
267 2015.1.01395.S 2 Resolving Molecular Clouds in a Low Metallicity Galaxy NGC 625 is a metal-poor dwarf galaxy whose unique combination of properties make it optimal for exploring the evolution of dwarf galaxies and of star formation. To start, as a low-metallicity, star-forming system with an intense radiation field and a high gas-to-dust ratio, it is an excellent astrophysical laboratory for studying the molecular interstellar medium (ISM) and star formation in an environment very different from spirals like the Milky Way. Distinguishing NGC 625 from other dwarfs are its complex neutral gas morphology and its prolonged star formation history. To understand its molecular ISM, we propose to map it in CO, which remains the leading molecule for determining the mass of molecular clouds and other global properties of the cold molecular ISM. Yet in low-Z galaxies, the CO luminosity is weak compared to high-Z galaxies. Fortunately, with ALMA, we have the powerful combination of high sensitivity and angular resolution to map molecular clouds in low-metallicity dwarfs beyond the Local Group. The goal of this proposal is to map NGC 625 in CO(1-0), in order to resolve and determine the properties of its giant molecular clouds. Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2017-09-23T05:57:41.000
268 2016.1.00481.S 32 Illuminate NGC 253 Nuclear Starburst by Ionized Gas Imaging with Parsec Scale Resolution We propose a high angular/spatial resolution observation of thermal free-free continuum emission in 100 GHz (Band 3) together with a hydrogen recombination line (H40alpha) toward a nuclear starburst galaxy NGC 253 in the ALMA Cycle 4. Based on data taken in the ALMA previous cycles, we successfully assessed properties of ionized gas. However, the limited spatial resolution data have constrained us to do inaccurate estimation of those values. Observations with high spatial resolution down to the Galactic compact HII region scale (0.''07=1.1 pc) assisted by the long baseline capability will push back the past limitations, and they provide not only ionized gas properties with the least ambiguity but also essential insights on the nature of the starburst activity, especially number of young massive stars and star formation rate. Starbursts, star formation, Galactic centres/nuclei Active galaxies 2018-11-08T20:58:28.000
269 2016.1.00177.S 70 Identifying molecular outflows in our neighborhood We have recently obtained an objective Herschel-based selection of local galaxies with extremely high far-infrared surface brightness log(Sigma_FIR)>~11.75. Their few 100pc size nuclear regions host intense and obscured star formation and/or AGN. Such regions are likely to launch powerful winds, and indeed the sample includes some well known examples of outflows in the molecular and other phases. Here, we propose deep moderate spatial resolution ALMA searches for CO (1-0) outflows in the seven remaining southern (DEC < +10) targets of that sample. If successful, detections will open the door for unique studies of structure and physics of molecular outflows. Aided by the proximity of targets with scales down to 150pc/arcsec, these can help to understand how outflows work and achieve the important effects that are assigned to them by current galaxy evolution studies. Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Active galaxies 2018-03-30T10:56:57.000
270 2017.1.00523.S 453 Gas accretion onto dense cores from early to late evolutionary phases of massive filamentary clouds High-mass star forming clouds often exhibit filamentary structures in which dense cores of ~<10 Msun are embedded. In order to form high-mass protostars, these dense cores must accrete gas from the environment. Such a picture, if proven universal, alters the current high-mass star formation models. However direct evidence of accretion onto dense cores in filaments is rare. We have selected 8 massive filamentary clouds encompassing a variety of evolutionary phases, and obtained VLA, SMA, and IRAM-30m data. Dense cores of ~<10 Msun are found in the filaments. Velocity gradients along filaments and infall signatures along the line of sight are found with VLA and IRAM-30m data, but the insufficient angular and spectral resolutions prevent us from tracing gas accretion onto dense cores. Here we propose to use ALMA to observe optically thick HCO+/HCN, and optically thin H13CO+/NH2D lines, in order to study both radial and axial gas accretion toward dense cores in filaments and inform high-mass star formation models. High-mass star formation ISM and star formation 2020-09-30T05:31:31.000
271 2013.1.00111.S 56 The extreme UV through ALMA's eyes: a unique probe of the ionizing power of starbursts and super massive black holes The extreme ultraviolet (EUV) of starforming and AGN sources cannot be probed directly from the ground or from space; their EUV are thus very poorly constrained. Our recent theoretical work demonstrates that the mm/submm recombination lines of HI and HeII are excellent probes of the EUV: they have little dust absorption, they arise from H and He (thus independent of metallicity) and their fluxes depend linearly on number of EUV continuum photons. The He++ region (producing HeII emission) requires 54 ev photons, thus the EUV hardness is directly proportional to the HeII/HI flux ratio. We propose observations of HI and HeII in compact OB star regions and galactic nuclei (SgrA* and NGC 1068). These observations will demonstrate the potential of the HI and HeII lines -- opening a new observing window on the EUV. Themeasured hardness of the EUV spectra will provide critical input to starburstsynthesis models. Based on prior near infrared line detections, we confidently expect expect detectios of the line emission in both SgrA* and NGC 1068. In the former, ALMA will image the 10^4 K ionized gas at 0.2 arcsec resolution (0.01 pc radius) for the first time. High-mass star formation ISM and star formation 2016-05-26T21:00:15.000
272 2019.1.01822.S 9 The molecular gas of a multi-phase filament in the lobes of Fornax A We propose to use the Atacama Compact Array (ACA) to study the distribution of molecular gas in a multi-phase gas filament at the outskirts of the nearby radio galaxy Fornax A. The 25 kpc long filament is located along a bridge of radio emission connecting the two giant radio lobes and at the edge of an X-ray cavity. The filament has been detected in Halpha as well as HI (3 x 10^7 Msun) and dust. Its properties are alike those of filaments of cooling gas detected around more distant and massive radio galaxies. The only exception is that those filaments are rich of molecular gas, too, while so far our target only has an upper limit. Here, we propose to observe the filament in 12CO(2-1) along its full extent (~4 arcmin), and resolve any molecular gas down to a molecular gas surface density of 1.0 Msun pc^-2. We expect molecular gas to be present as we already detect cool atomic gas and dust, although it is unclear how much of it might be present, and what its exact distribution and kinematics might be. Observing the molecular gas will enable us to quantify how gas is cooling within the filament and determine if star formation is on-going or may occur in this region. Outflows, jets and ionized winds, Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2021-03-09T15:10:08.000
273 2018.1.00864.S 7 Resolving the first radio outburst from a young massive star We have detected the first ever IR outburst from a young massive (>8 Msun) star (S255 NIRS3), which has important implications on our knowledge of the formation of early-type stars. The mere existence of an outburst favours models according to which massive stars form through disk accretion like their low-mass siblings. With a ~1yr delay with respect to the IR burst, we have detected also a radio burst that we have been monitoring from July 2016 to January 2018 with the JVLA, from 5cm to 7mm, and (on a shorter period) with ALMA and IRAM-NOEMA at 2 and 3mm. The radio emission has increased up to an order of magnitude and has been modeled with a fast expanding radio jet (Cesaroni et al. 2018). In the last JVLA image (Jan 2018) we have barely resolved the jet, unlike previous images with similar resolution. This proves that the observed flux increase is indeed due to an outburst causing expansion of the jet, as predicted by our model. We wish to resolve the jet with ALMA. For the first time, we will determine the physical structure of a thermal jet from a young massive star on scales below a few 100 au. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2022-10-29T20:54:56.000
274 2021.2.00099.S 90 Studying the Warm Gas in local Luminous Infrared Galaxies This filler program targets ACA observations of the CO(8-7), (7-6), and (6-5) molecular gas line emission and continuum emission in bands 10 and 9, for a group of ten U/LIRGs. The main purpose of these observations is to recover and map the integrated gas at high J transitions of these galaxies for the first time at ~ 2'' (1 kpc), a factor of ~20 improvement compared to existing Herschel observations. We will reveal for the first time the morphology of the highest excitation CO gas that can be accessed from the ground, and along with matched resolution lower CO observations will provide the highest resolution low to mid-J CO SLED in local U/LIRGs. Modeling such SLEDs will provide accurate estimates of the density and temperature of the gas and overall mass content at 1kpc scales. Merging and interacting galaxies Galaxy evolution 2023-07-22T16:29:53.000
275 2022.1.01479.S 11 CO Excitation Across the Local Galaxy Population Increasingly, extragalactic surveys trace the molecular gas with the CO(2-1) line. This relies on a down-conversion to the fundamental CO(1-0) line and too many studies simply assume average CO(2-1)/CO(1-0) line ratios (R21). However, recent studies find substantial R21 variation across and within galaxies. This has major implications for interpreting star formation scaling relations and characterizing the molecular gas. Before ALMA, R21 large sample studies were limited to poorer resolution and hampered by calibration uncertainties. This has restricted deriving firm quantitative conclusions. To take the next step, we propose new CO(1-0) observations to construct the first well-resolved, well-calibrated, and sensitive survey of R21 across a representative sample of 16 nearby galaxies. We will leverage public multiwavelength data to relate R21 variations to local conditions, galactic structure, and molecular cloud properties. ALMA observations are essential due to both their high angular resolution (~3 arcsec) and calibration stability. These observations will have major implications for key scaling relations and can be used to anchor large past and future CO(2-1) surveys. Surveys of galaxies Galaxy evolution 2024-05-04T00:00:00.000
276 2019.1.00577.S 10 Searching for phosphorus-bearing molecules in the ejecta of supernova 1987A Phosprhorus (P) is a crucial element for life as we know it, being a crucial constituent of biogenic molecules. It is created in massive stars and ejected in the ISM through supernovae. However, little is known about this element in space due to its low abundance, and many problems remain unsolved. In the last years, knowledge of its abundance in star-forming regions and evolved stars has considerably improved thanks to several new detections of P-bearing molecules. Atomic P has been also clearly detected in supernova remnants, but its measured abundance is much lower than expected to reproduce the P abundance in the ISM, and growing evidence suggests that a significant fraction of P could be in the form of molecules. We plan to observe the P-bearing molecules PN and PO in SN1987A, a unique laboratory to study the molecular composition of SN ejecta, in which recent ALMA observations have shown un unexpected high abundance of molecules thought to be formed similarly to PN. Our observations will put stringent constraints on the abundance of P at its source of production, and help to constrain supernova explosion models. Supernovae (SN) ejecta Stars and stellar evolution 2022-11-08T08:05:10.000
277 2013.1.00937.S 4 Tracing the onset of star formation with ALMA We propose to observe with ALMA six centrally concentrated, highly evolved starless cores in the cluster-forming Ophiuchus molecular cloud. The selected targets include cores both within and outside of the larger Oph filaments. Despite their highly concentrated single-dish submillimetre features and small-scale structure as probed by interferometric NH3 observations, 70 micron non-detections indicate that any embedded protostars are very low luminosity, with upper limits L_int < 0.1 L_Sun for most of the targets. The proposed observations will reveal the core structure at 0.25" resolution (30 AU) at 359 GHz continuum, and the core kinematics using the dense gas tracer H2D+, critical to identify rotation and infall in the dense gas. Finally, we will search for slow outflows potentially driven by embedded first hydrostatic cores or extremely young embedded protostars undetected at 70 micron. Low-mass star formation, Astrochemistry ISM and star formation 2016-09-11T05:29:10.000
278 2018.1.00046.S 74 An Unprecedented Census of the Molecular ISM in Starburst Galaxies at the End of Cosmic Reionization We propose a full molecular line inventory in Bands 3 and 4 of four of the highest known redshift dusty starburst galaxies accessible by ALMA, at z~5.7, close to the end of cosmic reionization. Our previous ALMA spectroscopy in two DSFGs at similar redshifts, show striking results, anticipating a new era for molecular ISM studies in high-z galaxies. We expect to detect more than 40 lines of 13 molecular species in each object, tracing the full range of excitation conditions, heating mechanisms, outflow and dynamical signatures, and chemical enrichment pathways. At these rest frequencies, our observations will match and even exceed the sensitivity of local starbursts observed by Herschel/SPIRE. By exploiting high-resolution ALMA 870um continuum observations, low- and mid-J CO observations with ATCA and ALMA, [CII] emission from APEX, and full optical-to-radio SED coverage, these observations will stand as the definitive view of the ISM conditions in these objects, serving as an effective comparative study to local starbursts (e.g. Arp220) and intermediate-redshift analog systems (e.g. the Eyelash). Sub-mm Galaxies (SMG), Gravitational lenses Galaxy evolution 2019-12-27T15:30:10.000
279 2016.1.00728.S 22 Characterizing the first directly imaged water snow-line in a protoplanetary disk In ALMA Cycle 3, our group serendipitously imaged the water snow-line in the protoplanetary disk around V883 Ori, a 1.3 M_sun protostar undergoing a massive FU Ori accretion outburst (Cieza et al. submitted to Nature). Our Band-6 observations revealed a sharp break in optical depth at a location where the disk temperature reaches the sublimation point of water. At this discontinuity, the disk shows a clear change in the spectral index, as predicted by recent water snow-line models (Banzatti et al. 2015). Due to the enormous accretion luminosity, this water snow-line lies at > 40 au as opposed to < 5 au as typically expected for solar-type objects. The V883 Ori disk thus represents a unique opportunity to characterize the water snow-line using an ample frequency leverage at the highest resolution available for Cycle 4. Our immediate objectives are 1) Constrain the temperature of the observed water snow-line, 2) Investigate the role of viscous heating in the thermal structure of the V883 Ori disk, and 3) and test dust evolution models. The V883 Ori disk is so bright that our observations, including overheads, require just 1 h per band. Disks around low-mass stars Disks and planet formation 2018-11-24T13:41:34.000
280 2017.1.01076.S 43 A Protoplanet Interacting with an Edge-on Circumstellar Disk We have discovered a companion to a very young star using HST. The object is projected at the outer radius of an edge-on protoplanetary disk and appears coplanar with the disk. Keck AO photometry indicates the object has the same temperature as brown dwarf GQ Lupi B but with 10x less luminosity - consistent with a planetary mass object. Keck AO spectroscopy detects 2.12 micron H2 emission from the companion, confirming its youth and excluding a background object. We propose band 6 continuum and CO isotopologue observations to 1) measure spatial and velocity asymmetries in the outer disk and show that the gas there is moving in a two-body potential; 2) detect a separate disk around the companion; 3) use disk rotation curve(s) to derive the mass of the component(s); and 4) resolve the disk vertical structure. With a substellar spectral energy distribution, accretion signatures (the subject of a pending HST proposal), and the demonstration of gravitational interaction with disk gas, this object would be established as the leading example of an accreting protoplanet at 100 AU and offer support to models of planet formation by gravitational instability. Disks around low-mass stars, Exo-planets Disks and planet formation 2019-01-30T23:13:09.000
281 2021.1.01495.S 10 Revolutionary insights into the z>7 gas and dust physics Although high-z galaxy sample sizes with FIR line and dust continuum detections have known a boost with ALMA, the characterisation of their gas and dust reservoirs remains elusive. We propose to target six FIR lines ([OIII]52,88,[NII]122,[OI]145,[CI]370,CO7-6) and the underlying dust continuum in the brightest [CII]- and dust-detected z=7.306 galaxy (UVISTA-Y-003). This ambitious program will allow us to unambiguously constrain the gas densities, ionisation parameter, ionising photon escape fraction, molecular gas mass and gas-phase O, C and N abundances. We will gain unprecedented insights into the early metal and dust enrichment, the efficiency of star formation, and the contribution of massive galaxies to cosmic reionisation. The exquisite sampling of the rest-frame 52-370 micron dust SED comes for free, and will enable us - for the first time - to cover the z>7 dust SED peak and to constrain the dust temperature, mass and IR luminosity with high precision. The IR luminosity will be crucial to interpret the IRX-beta diagram; whereas the metal and dust masses will allow us to tie down the dominant dust production sources and the importance of gas accretion and outflows. Starburst galaxies Active galaxies 2023-08-18T16:00:18.000
282 2022.1.00728.S 0 Exploring the giant planet-forming potential of disks in the high UV environment of the Sigma Ori cluster Detections of gaps and rings in protoplanetary disks have implied that giant planet formation occurs readily at separations of tens or sometimes even hundreds of au. Our current understanding of the demographics of giant protoplanets, though, has largely been shaped by high resolution observations of disks in the nearby low-mass star-forming regions Taurus, Lupus, and Ophiuchus. Snapshot surveys of regions with high UV radiation fields, which may be more representative of the formation conditions of our own Solar System, suggest that their disks are more strongly affected by photoevaporation compared to the nearby low-mass star-forming regions. To investigate how extreme environments can influence planet formation, we propose an exploratory high resolution study to characterize signatures of planet-disk interactions in the Sigma Orionis cluster. Disks around low-mass stars Disks and planet formation 2024-09-14T15:50:14.000
283 2021.1.01207.S 21 Uncovering the nature of an extremely optically dark SMG at z=5 Among bright, dusty star-forming galaxies (submillimeter galaxies, SMGs), some are known to be the "optically dark" SMGs, which are completely blank at optical-to-near-infrared (NIR) wavelengths. Some are not detected even in deep IRAC images, and the nature and the role in galaxy evolution of these "extremely optically dark" SMGs is still unclear. We propose to observe CO(7-6), [CI](2-1), and [CII] for AzTEC26 at z = 4.568, which is an extreme case of the optically dark SMGs, using ALMA Band4 and Band7. Combining with the archival CO(5-4) and [CI](1-0) data, we will evaluate CO excitations (from CO(7-6) and CO(5-4)) and uncover gas kinematics (via [CII]). On the basis these clues, we will address the issues: (i) what causes the extreme faintness in the optical to NIR, and (ii) what stages of massive galaxy formation do they account for. Sub-mm Galaxies (SMG) Galaxy evolution 2023-06-07T10:52:32.000
284 2016.1.00223.S 63 Dissecting the monolithic molecular core G31.41+0.31 In a previous ALMA project we imaged the massive core G31.41+0.31 at 1.3mm with 0.2" resolution. The results provide us with contradictory evidence: on the one hand, (i) the core looks very homogeneous and appears to undergo solid-body rotation; on the other hand, (ii) we find evidence of rotation+infall that speeds up towards the core center, while the presence of two embedded massive stars suggests that fragmentation has already occurred. We believe that the apparent contradiction between (i) and (ii) can be due to large continuum opacity at 1.3mm and insufficient angular resolution. Therefore, to establish whether the core is indeed as monolithic as it appears, or is undergoing global fragmentation, we propose to: (1) improve on our previous 1.3mm images by increasing the resolution to 0.08", to resolve the absorption region and hence investigate the infall; and (2) extend the continuum imaging to 3mm, at the maximum possible resolution at this band (0.08"). At 3mm the dust opacity is up to 4 times lower and it should be easier to reveal fragmentation on scales of ~0.2", comparable both to the Jeans length and the separation of the two embedded massive stars. High-mass star formation ISM and star formation 2019-01-11T18:52:56.000
285 2016.1.00569.S 135 Characterizing Absorption-Selected High-z Galaxies (CASH) Survey Our successful Cycle 3 proposal to detect [CII] emission from the highest HI column density absorbers (known as Damped Ly-alpha Systems; DLAs) at z~4 has resulted in the first two detections of this line for absorption-selected galaxies; a population of galaxies that traces 'typical' galaxies due to their unbiased selection technique with respect to luminosity. The current proposal expands on our pilot program by more than tripling the sample size. With this expanded sample, we will be able to definitively characterize the size, mass and impact parameter distribution of the galaxies responsible for the high metallicity end of the DLA galaxy population at z~4; an objective that has eluded all major observational facilities thus far. As a corollary, we will also be able to explore the metallicity dependence of the star formation rate (SFR) to total [CII] luminosity scaling relationship. We emphasize that targeting DLA galaxies has proven to be an effective way to detect [CII] emission from moderate to low star-forming galaxies (SFR > ~5 Msun/yr) at z~4, and thus complements the typical luminosity-based samples covering this SFR range. Damped Lyman Alpha (DLA) systems Cosmology 2018-02-10T18:34:38.000
286 2011.0.00087.S 0 Structure of the beta Pictoris disk in mm dust We propose to image the brightest debris disk - beta Pictoris - with ALMA in band 7. The primary aim is to study the distribution of mm-size dust on scales from ~150AU down to ~10AU. This will enable us to delineate the location of the colliding planetesimals which are the ultimate cause of the debris cascade in such disks. This will be compared with the distribution of small grains seen in scattered light, the hot dust seen in the mid-IR and the location of the planet beta Pictoris b, in order to test existing models and improve our understanding of the archetype debris disk. The images will probe the mm-grain population of structures including the 100AU ring, outer disk, inner clumps and warp or inclined disk. Simultaneously we will be performing a deep search for emission from the circumstellar CO in the disk, probing the origin of the gas and the nature of the parent planetesimals. Debris disks Disks and planet formation 2014-02-07T14:10:00.000
287 2013.1.00214.S 5 CO observations covering the entire N55, the best example of stochastic self-propagating star formation, in Super Giant Shell 4 in the LMC We propose here an ALMA observation of molecular gas toward an HII region, N55, in the Large Magellanic Cloud (LMC), which is a cometary-shaped GMC that is being affected by multiple supernova explosions. The Spitzer/Herschel images show peculiar features in this region; there are a lot of filaments and clumps entangled with a size scale of a few pc, and then this structure may be formed by an effect of shocks from the supernova explosions. It has been known that supernova explosions play an important role in evolution of the ISM to form dense structure in the molecular clouds, leading to star formation. In particular, the ISM evolution in the dwarf irregular galaxies, which are not affected by the density wave or arms, is expected to be affected by explosive events observed as shells and supergiant shells. The observations of N55 in CO lines enable us to derive detailed physical properties of the possibly induced star forming GMC, leading to an understanding of the role of the supernova explosions and filaments on star formation in molecular clouds. Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds ISM and star formation 2017-01-06T00:00:00.000
288 2022.1.00207.S 6 Mapping magnetic fields at cloud scale Models of massive star formation show that magnetic fields play a significant role, preventing fragmentation, slowing cloud collapse, and influencing the formation of accretion disks and jets. However magnetic fields are still poorly known, in particular at the initial stages of massive star formation. In the last years, we have built up a sample of high-mass star-forming regions for which we are performing a multi-scale study, from cloud scales to disk/jet scales, of the role of magnetic field. Our study combines polarization observations of masers and dust continuum at different spatial scales in 9 massive star-forming regions. We have almost completed the observations at core and disk/jet scales but still miss large-scale polarization observations to trace the magnetic field at cloud scales. These large-scale observations is what we propose to carry out here with ACA in Band 6. By comparing the magnetic field measurements at different scales, we will obtain a complete view of its properties in a significant sample of massive star-forming regions spanning a wide range of luminosities and will test the magnetic field consistency across different spatial scales. High-mass star formation ISM and star formation 2025-03-22T15:44:45.000
289 2018.1.01737.S 7 V* V1094 Sco: optically thin continuum observations for a rare giant multi-ringed disk A key ALMA discovery is the unexpectedly wide variety of structures in protoplanetary disks. We recently serendipitously discovered a new, huge (dust outer radius of 300 AU) multi-ringed disk around V1094 Sco in ALMA Band 6 and 7 data. Recent VLT-SPHERE/IRDIS scattered-light and higher-resolution ALMA images also show rings and substructure in this disk, down to even smaller scales. Disks the size of V1094 Sco are rare; it is in the top 2% of Lupus disks by radius. With structure at many scales, and evidence for a radially varying spectral index, V1094 Sco can be a key probe of dust ring formation mechanisms. However, a key observable is missing: in Band 6, the inner 35 AU are optically thick, and the interpretation of the spectral index of the dust is ambiguous due to low spectral leverage. This prevents us from analyzing dust structure and grain growth in this crucial area. We propose ALMA observations in Band 3 at 0.057" resolution, imaging the dust in the center of this key object with an optically thin tracer for the first time. Our proposal combines VLT-SPHERE and ALMA observers to study the origin of multiple rings in disks. Disks around low-mass stars Disks and planet formation 2021-01-18T00:49:41.000
290 2023.1.01214.S 0 Circumnuclear Holes around Supermassive Black Holes Galaxies and supermassive black holes (SMBHs) are likely co-evolving, and the most accepted paradigm is an evolutionary process that involves self-regulating feedback from active galactic nuclei (AGN). Recent high-resolution observations of nearby galaxies are revealing ~10-100 pc CO holes at their circumnuclear regions in 20 % of the galaxy, independent of their current nuclear activity. The origin of these circumnuclear holes are unknown, but their radii typically corresponds to the SMBH potential, suggesting that the SMBHs are the cause. If these holes are developed without powerful AGN, the SMBHs must be creating these holes through heating or dynamical effects. This suggests secular effects can impede accretion of gas, making it harder for AGN accretion to occur. To unravel the cause of these circumnuclear holes, we propose to observe the HCN(1-0), CO(1-0) and CO(6-5) lines in three galaxies with known CO(2-1) holes, to probe the presence of gas and analyse the physical state of the SMBH surroundings. The results will help to clarify the origin of circumnuclear holes, and thus will reveal direct evidence of their feedback even without a luminous AGN. Merging and interacting galaxies Galaxy evolution 2025-01-22T13:11:44.000
291 2019.1.00500.S 4 A Moment of Truth with ALMA CN Zeeman Observations: Is Disk Accretion Really Driven by Magnetic Fields? Magnetic fields are believed to be essential to the process of accretion in circumstellar disks. Attempts to measure the strength and morphology of disk magnetic fields through dust continuum polarization have so far proven unsuccessful; the observed polarization patterns in the disk could be better explained by scattering and radiative alignment. We propose to obtain measurements of the magnetic field strengths in the disks of AS 209 and V4046 Sgr through measurements of Zeeman splitting in the CN 2-1 and CN 1-0 transition lines. Zeeman splitting offers a direct probe of the line-of-sight magnetic field without contamination from scattering and radiative alignment. Observations of the disks magnetic fields will offer evidence for or against current theories of magnetically driven accretion. These observations would significantly advance the commissioning of future Zeeman observations for both disks and star formation. Debris disks Disks and planet formation 2021-09-04T21:05:42.000
292 2021.1.00898.S 17 The extremely peculiar globular cluster system of UDG GAMA-526784 and its implications Observations of Ultra-Diffuse Galaxies (UDGs, with luminosities of dwarfs but sizes of giant galaxies) have picked up a lot of attention by the community. Two nagging problems are 1) the apparent lack of dark matter of some UDGs and 2) their anomalously abundant-and-bright globular clusters. The former is difficult to reconcile with a LCDM model of structure formation, while the latter is contrary to observations in any other galaxy. A newly discovered UDG may provide valuable insight towards solving both problems. This unique object has similar properties to typical UDGs, apart from a widely spread population of compact star-forming regions. Some properties of this galaxy are similar to those hypothesised by Silk 2019, who predicts the formation of massive globular clusters (GCs) and links it to the formation of UDGs that lack dark matter. We aim to measure the molecular gas content of the regions, constraining the depletion timescales and the expected final mass of the star clusters. With ACA we will constrain the molecular gas content and, possibly, dynamical state of the whole galaxy, assessing if it lacks dark matter. These are essential ingredients to test the Silk 2019 model Giant Molecular Clouds (GMC) properties ISM and star formation 2023-08-11T14:42:18.000
293 2021.2.00129.S 18 The Nearby Evolved Stars Survey: quantifying the gas and dust return to the Galactic interstellar medium Outflows of asymptotic giant branch and red supergiant stars drive local galactic chemical evolution. The Nearby Evolved Stars Survey (NESS) is a global project targeting a volume-limited sample of evolved stars within 2 kpc to constrain the physics driving mass loss. NESS includes ongoing JCMT (515 hr) and APEX (56 hr) surveys to observe CO(2-1), CO(3-2) and dust continuum from ~500 sources, and at the Nobeyama observatory (190 hr) for CO(1-0). We propose 12CO and 13CO(2-1) and (3-2) observations of the 207 NESS sources visible to the ACA that do not have archival data (total sample 301 sources). Combining the high resolution and large field-of-view of the ACA with data from the JCMT and APEX, we will thoroughly probe their inner shells, revealing the mass-loss history, geometry and the 12C/13C and dust-to-gas ratios. The large, volume-limited sample will robustly constrain the onset of mass-loss variations and asymmetry. All NESS data, including reduced data, catalogues, codes and model results will be publicly available. The NESS database is poised to become the authoritative source for evolved-star studies in the next decade, and the proposed ACA data will be a vital addition. Asymptotic Giant Branch (AGB) stars Stars and stellar evolution 2023-05-09T05:02:18.000
294 2023.1.01436.S 0 Redshifts for the Brightest High-z Dusty Sources from Nearly Half the Observable Universe We seek redshift confirmation of outstanding lensed, sub-millimeter galaxy targets that we have found in an 18,000 sq. deg survey. This is a seven-fold increase in the sky area previously surveyed for such galaxies. Sub-millimeter galaxies have among the highest star formation rates in the Universe and occur at such early times that they can challenge our understanding of galaxy evolution. They serve as excellent targets for JWST characterization. Probing the progenitors of massive elliptical galaxies, our investigation addresses ALMA's science driver on the origin of galaxies. Our conservative, multiband selection uses data at 150 GHz, 220 GHz and Planck 857 GHz to generate a sample of 31 bright, dusty, and likely high-redshift candidates. Our pipeline independently finds nine galaxies with verified redshifts z > 3. We have cross-matched against extra-galactic catalogs to identify potential foreground lenses, and inspected optical images. ALMA provides an ideal facility to confirm the redshifts of these extreme objects: we propose spectral scans of ALMA band 3 to measure lines of CI and CO. Sub-mm Galaxies (SMG) Galaxy evolution 2025-06-07T19:58:07.000
295 2017.1.01578.S 0 Can dynamics in the transition disk of HD 34282 create a spiral and/or a vortex? The transition disk around HD 34282 shows strong indications of dynamics driven by a sub-stellar companion orbiting inside the disk: with previous ALMA and VLT/SPHERE (NIR) observations we have detected an inner cavity, a tightly wound one-armed spiral and an asymmetric enhancement that could trace a vortex. We propose to observe HD 34282 in band 6 at a spatial resolution similar to that of SPHERE (0.04'') to: [a] find the dynamical signature of the companion disturbing the CO velocity map; [b] determine whether the sub-mm disk indeed contains a vortex or a previously unresolved spiral as detected in the small grain disk surface with SPHERE. Radiative transfer and dynamical modeling will be applied to characterize the detected disk structures and explain their origin. This is the only transition disk ever detected that displays these three important tracers of a companion simultaneously. It is therefore bound to become an important benchmark for future hydrodynamical simulations. Disks around high-mass stars Disks and planet formation 2018-12-09T05:30:41.000
296 2015.1.01056.S 40 ALMA Mapping of a Great Case of Ongoing Ram Pressure Stripping in the Nearby Virgo Cluster We propose to map CO(2-1), CO(3-2) and 870um continuum in the spiral NGC~4402, one of the best cases of active ram pressure stripping in the nearby Virgo cluster. HST images reveal a remarkable variety of ISM features associated with ongoing stripping that we would like to characterize, including kpc-scale head-tail filaments, small decoupled clouds, ablated extraplanar dust plumes, several-kpc-long extraplanar dust fronts, and leading edge star-forming complexes. We will measure cloud sizes, linewidths, masses (gas and dust), and CO(3-2)/CO(2-1) ratios, and compare cloud properties with various nearby galaxies, to learn whether the clouds which appear to be affected by ram pressure have distinct properties. We can determine the cloud mass function and its spatial variation, to explore whether ISM compression along the leading edge results in more massive clouds, and estimate the fraction of the ISM mass that decouples during stripping. Comparison of simulations with these detailed observations of gas being stripped from the disk will give us a better understanding of the efficiency of stripping, and therefore its impact as a quenching mechanism throughout the universe. Spiral galaxies, Galaxy groups and clusters Local Universe 2017-05-06T18:06:59.000
297 2012.1.00423.S 0 The evolution of the molecular gas content at z>3 Revealing the origin of the enhanced cosmic star formation rate density at high redshifts is fundamental for understanding galaxy evolution, because it is responsible for producing the bulk of stars observed locally. Recent observations and theoretical studies have suggested that the evolution of the cosmic star-formation rate is not regulated by variations of the star-formation efficiency (due to merger/interaction processes), but by the evolution of the content of molecular gas in galaxies. This can be examined observationally, and actually galaxies at z~2 show much higher gas fraction than local galaxies, in agreement with theoretical expectations. At z>3 the situation remains uncertain. The few CO measurements of submillimeter galaxies (SMGs) and extremely bright Lyman-break galaxies (LBGs) at z~3 available today indicate lower gas fractions (20-50%) than predicted. However, those galaxies with SFRs up to ~1000 Msun/yr are not representative of the bulk of star-forming galaxies at z~3. Moreover, their metallicities remain poorly constrained, hence the CO-to-H2 conversion is highly uncertain. Here we propose to measure the gas fractions of four `normal' galaxies at z~3.0-3.5 through ALMA band 3 observations of CO emission. We focus on four LBGs investigated in the AMAZE project (an ESO Large Program; Maiolino, Nagao, et al. 2008), which is based on near-infrared integral field observations with VLT/SINFONI. The selected galaxies are optimal targets for achieving our scientific goal because they are representative of the usual, UV-selected LBG population, contributing to the bulk of the star formation activity at those redshifts. Also, these galaxies are very well studied, and their properties such as metallicity (which allows for direct inference of the critical CO/H2 conversion factor), stellar mass, morphology, and dynamics are well determined from a large collection of data, including SINFONI spatially-resolved near-IR spectroscopy, HST optical and near-IR imaging, and Spitzer mid-IR photometry. The obtained gas content information of the targets will enable us, for the first time, to identify the dominant mode of star formation at z>3. Lyman Break Galaxies (LBG) Galaxy evolution 2015-03-24T12:46:43.000
298 2016.1.00333.S 31 [OIII] observations towards the z=6.027, gravitationally lensed galaxy A383-5.1 We have discovered redshifted [CII] in the z=6.027 star-forming A383-5.1. It is the so-far faintest and only [CII] detection at z>6 in a normal star-forming galaxy. A383-5.1 has a star-formation rate of 3.2 Msun/yr, similar to that of the Milky Way, low metallicity (log(Z/Zsun) = -1.33), and is gravitationally lensed by a factor 11.4. We propose to do Cycle-4 ALMA observations of the [OIII] 88um emission line in order to characterise the physical conditions of the ISM in A383-5.1. With very few [CII] detections in other z>6 galaxies, it is difficult to make predictions for the far-infrared fine-structure lines for other galaxies, however, with the [CII] detection in hand and the fact that A383-5.1 has a low metallicity as well low dust content, it is an ideal candidate to search for the expected bright [OIII] 88um line. Generally, FIR fine-structure line observations in the early universe is still an unchartered topic with very few detections, hence a detection of [OIII] would provide valuable insights into the physical conditions of early galaxy evolution. Lyman Break Galaxies (LBG), Gravitational lenses Galaxy evolution 2019-10-19T19:54:20.000
299 2018.1.00681.S 124 Unveiling molecular gas contents within normal star-forming galaxies at z~3.3 Star-forming galaxies at z=3-4 are expected to be in a phase of an accelerated growth towards z~2, which requires a gas inflow from the outside. Such a prominent gas inflow is also suggested from the observational results that star-forming galaxies at z>3 do not follow the same stellar mass-SFR-gas metallicity relation as galaxies at z=0-2. At z > 3, the cosmological gas inflow is likely to be dominant and hence cause the dilution of gas metallicity. In order to investigate how the inflow/outflow processes are involved in the star formation activities and interstellar medium conditions of young galaxies at z>3, it is essential to measure the molecular gas contents of these galaxies. We propose dust continuum observations at Band-6 of 12 star-forming galaxies at z~3.3, for which we have already measured gas metallicities from the Keck/MOSFIRE spectra. We estimate molecular gas masses from the dust continuum and derive gas mass fractions and star formation efficiencies by taking into account the gas metallicities. Moreover, by combining the gas metallicities, SFRs and gas mass fractions with chemical evolution models, we will constrain the inflow/outflow rates of galaxies at z~3.3. Lyman Break Galaxies (LBG) Galaxy evolution 2020-07-09T22:35:46.000
300 2012.1.00178.S 3 Deuterated Ammonia in Prestellar Cores Stars form in molecular cloud cores, cold and dense regions enshrouded by dust. The initiation of this process is among the least understood steps of star formation. High-resolution heterodyne spectroscopy provides invaluable information about the physical conditions (density, temperature), kinematics (infall, outflows), and chemistry of these regions. Classical molecular tracers, such CO, CS, and many other abundant gas-phase species, have been shown to freeze out onto dust grain mantles in prestellar cores. However, N-bearing species, in particular ammonia, are much less affected by depletion and are observed to stay in the gas phase at densities in excess of 106 cm-3. The molecular freeze-out has important consequences for the chemistry of dense gas. In particular, the depletion of abundant gas-phase species with heavy atoms drives up abundances of deuterated H3+ isotopologues, which in turn results in spectacular deuteration levels of molecules that do remain in the gas phase. Consequently, lines of deuterated N-bearing species, in particular
the fundamental lines of ammonia isotopologues, having very high critical densities, are optimum tracers of innermost regions of dense cores. We propose to study the morphology, density structure and kinematics of a prototypical dense cloud core, by mapping the spatial distribution of ammonia isotopologues in L1689N using ALMA in its most compact configuration. These observations provide optimum probes of the onset of star formation, as well as the physical processes that control gas-grain interaction, freeze-out, mantle ejection and deuteration. The sensitive, high-resolution spectra acquired within this program will be analyzed using sophisticated radiative transfer models and compared with outputs of state-of-the-art 3D MHD simulations and chemical models developed by the members of our team. Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2021-03-12T00:00:00.000
301 2019.1.00567.S 8 Directly measuring the progression of infall from the envelope to the disk-forming region of BHR 71 Infall transforms dense cores into protostars. During the embedded phase of star formation, the evolution of infall determines the final mass of the central protostar as well as the initial condition of the disk and planet formation. Theoretical studies still debate about the types of infall, the "inside-out" or "outside-in" fashions, and the effects of rotation and magnetic fields; only few direct observation of infall exists to constrain the infall process. Previously, we have detected an unambiguous signature of infall, toward an embedded protostar, BHR 71, and modeled the infall kinematics. To trace the progression of infall, we propose here to measure the radial variation of infall toward BHR 71 via multiple transitions of HCO+, empirically probing the infall at different radii, and the resolved emission of complex organic molecules (COMs), tracing the kinematics close to the disk. We will trace the kinematics from the envelope (~1000 au) to the disk-forming region (~30 au), identifying the type of infall and probing the transition from infall to rotation. Furthermore, we will survey the high frequency emission of COMs to complement the previous discovery of COMs. Low-mass star formation ISM and star formation 2022-08-12T23:07:00.000
302 2015.1.00534.S 9 Probing Planet-Forming Zones in Orion Nebula Cluster Disks We propose to mosaic the central 1.5' x 1.5' of the Orion Nebular cluster (ONC) at 350 GHz with ALMA. With an angular resolution of 0.08'', we will resolve linear radii smaller than 25 AU in the circumstellar disks of ONC cluster members. Our mosaic will encompass >150 cluster members within a uniform sensitivity region where we can detect average disks at the 3sigma level. An additional ~50 objects in the outskirts of our field will be included at somewhat reduced sensitivity. Continuum observations of this sample will produce the deepest and most accurate disk mass distribution to date, and will constrain the planet-forming potential of a population of young stars in an environment that is typical of star formation in the Galaxy and also resembles our own Sun's birthplace. In addition, observations of CO and HCO+ will probe the disk gas content and allow us to measure stellar masses through disk dynamics. These lines will also allow us to study feedback processes at the scales of disks and evelopes. This program will resolve solar system scales in ONC disks, and constrain planet formation models directly for the first time in a clustered star forming region. Disks around low-mass stars, Disks around high-mass stars Disks and planet formation 2018-04-13T01:18:02.000
303 2015.1.00773.S 56 An ALMA Search for Disks around Planetary Mass Companions In the last decade, direct imaging surveys have discovered dozens of planetary mass companions (PMCs) at ultra-wide separations from their host stars. The origin of these objects remains unclear, as canonical planet formation theories are not effective at such high radii. Recent studies, however, suggest that these enigmatic objects may be surrounded by disks of primordial material. Direct detection and characterization of these disks provides a new avenue for studying the formation of PMCs as well as their potential exomoon systems. Here we propose to survey 7 PMCs which show indirect evidence for the presence of such a disk. With ALMA we will image those disks and calculate disk masses to constrain PMC evolutionary paths as well as the amount of material available to form exomoons. We will also use 0.1" spatial resolution to resolve circumplanetary disks, measure their sizes and structures, search for CO (2-1) emission to measure Keplerian rotation and thereby dynamical masses for PMCs, and trace disk evolution by comparing disk morphology at different ages. This proposal is an important first step towards better understanding the formation of PMCs and exomoon systems. Exo-planets Disks and planet formation 2018-01-29T08:44:41.000
304 2021.1.00581.S 20 Radial Distributions of Sufur-Bearing Species in Disk Forming Regions Sulfur-bearing species (S-species) are now spotlighted in astrochemistry and astrophysics. First, S-species such as H2CS and OCS are found to trace the protostellar and protoplanetary disks around Solar-type protostars. Second, they are detected in the Solar System comet, suggesting a possible link between the interstellar and planetary chemistry. Although chemical differentiation of S-species is recognized in disk-forming regions, it is not understood in terms of chemical processes. This is because the distributions of S-species, including H2S the major reservoir of S-atoms specifically, in disk-forming regions are still obscure. To overcome this situation, we here propose to delineate the radial distributions of fundamental S-species in Band 5 at a high angular resolution toward four young protostellar sources: IRAS 16293-2422, Serpens SMM 1/4, and B335. We also evaluate the temperature distribution in disk-forming regions by using the multiple lines of H2CS. The result will constitute a valuable template for studies on sulfur chemistry in protostellar sources. Low-mass star formation, Astrochemistry ISM and star formation 2024-06-01T23:00:17.000
305 2013.1.00884.S 77 What impact do luminous AGN have on star formation? One of the outstanding issues in the formation and evolution of galaxies is a definitive measurement of the impact that AGN have on Star Formation (SF). Observationally the picture is very mixed with conflicting results arguing for all scenarios: luminous AGNs suppressing, enhancing, or having no impact on SF! A major issue is the lack of sufficiently deep FIR-submm observations to directly measure the SF properties for the majority of the AGN population. The primary aim of this proposal is to build on our ALMA cycle 1 programme, combined with our carefully deblended Herschel photometry, to measure individual SFRs for a complete sample of X-ray selected AGN over the key X-ray luminosity and redshift ranges (L_X=10^43-10^45 erg/s and z=1.5-3.2), where the impact of AGNs on star formation is thought to be most prevalent. With the proposed observations we will construct detailed SFR distributions as a function of key AGN properties to accurately measure the impact that AGN have on SF in their host galaxies. Our observations will provide a key test for galaxy formation models which employ a wide variety of different prescriptions of AGN and SF activity. High-z Active Galactic Nuclei (AGN) Active galaxies 2016-02-03T14:00:41.000
306 2012.1.00678.S 7 Sculpting Round Circumstellar Envelopes into Bipolar Nebulae: A CO J=3-2 study of the Water-Fountain Nebula IRAS16342-3814 We propose to map the jet outflow in the bipolar pre-planetary nebulaIRAS16342-3814 in the CO J=3-2 line with 0.22 arcsec resolution. Planetarynebulae (PNe) show a dazzling variety of elliptical, bipolar and multipolarmorphologies, and hydrodynamic sculpting of the progenitor AGB star'sspherically-symmetric circumstellar envelope by wandering and/or episodic jetsfrom the inside-out is one of the most promising mechanisms for shaping PNe. Theproposed study of IRAS16342-3814, the most prominent member of a class of youngPPNs called "water-fountain" nebulae in which the jet activity is extremelyrecent, will enable a significant advance in quantitatively understanding thejet-sculpting process. High-resolution HST and Adaptive Optics images ofIRAS16342-3814 and VLA/VLBA interferometry indicate nebular shaping inaction in this object. ALMA mapping of the CO line emission in IRAS16342-3814,which will enable us to determine the temperature and mass of acceleratedmaterial as a function of radius, latitudinal angle and velocity, is now neededto understand the jet dynamics and build quantitative models of jet-shaping.Our observations will also directly detect, for the first time, material inthe dark, dusty waist separating the bipolar lobes, enabling us to determine its mass and kinematics, and thus constrain its origin, which is currentlyunknown. Post-AGB stars, Evolved stars - Shaping/physical structure Stars and stellar evolution 2016-10-16T02:38:40.000
307 2016.1.00176.S 1 NGC 1068: a torus created by a magnetic wind ALMA Band 6 has resolved, ~10 pc diameter, the torus of NGC 1068, whose morphology and kinematics suggest to be the signature of a magneto-hydrodynamical (MHD) instability. Our subarcsecond infrared polarimetric observations have shown that the polarization from the inner edge, ~0.4 pc, of its torus is dominated by magnetically aligned dust grains in an wind. These studies suggest that the origin, evolution and morphology of the torus can be explained as a MHD wind. However, a convincing demonstration that large-scale magnetic fields are present in the torus is required to confirm/reject the MHD wind. We propose to obtain a polarized continuum flux image of the dusty torus of NGC 1068 using ALMA Band 7 at a spatial resolution of 0.05" (3.4 pc). As polarimetry is a vector quantity, this spatial resolution is crucial to resolve and enhance the contrast of the torus from other (un-)polarized components. The proposed Band 7 data and our infrared polarimetric observations, will enable us to construct the finest and broadest nuclear polarized SED of NGC 1068, that in combination with our own polarization models, will allow us to physically constraint the MHD wind. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 2018-11-30T21:40:15.000
308 2013.1.00489.S 10 Are there disks around O-type protostars? Our objective is to establish whether circumstellar disks exist around O-type (proto)stars, and to characterize them. This is crucial because theory predicts that disk-outflow systems can solve the "radiation-pressure problem" and explain the formation of stars up to 140 Mo. In a Cycle 0 proposal, we found 2 Keplerian disks around young B-type stars. The success of our experiment indicates that disk accretion is the formation route of stars up to 20 Mo. We now wish to extend our search to the most massive stars. We have selected the 6 best possible targets based on the luminosity, IR colour, distance, and association with hot-core tracers and outflows. We wish to observe known disk tracers such as CH3CN in the C34-7 configuration in band 6, to attain about 0.2" resolution, sufficient to resolve disks whose size is predicted to be >0.5". We will interpret the data by means of numerical simulations already available to us. We stress that our project will be successful even if no disk should be detected, because we will set a tight upper limit on the disk diameter and prove that disk-mediated accretion in O-type stars is not as effective as in lower-mass stars. High-mass star formation ISM and star formation 2016-12-07T22:02:42.000
309 2017.1.01729.S 87 Monitoring radio emission of the youngest planetary system with ALMA Millimeter or submm emission has never been detected from exoplanets or their hosts up to date. The recently discovered hot Jupiter V830 Tau b orbiting a weak-line TT star with a strong magnetic field is a promising system for a first detection in submm wavelength. The system has been detected twice in centimeter by VLA and VLBA among 5 observations, and thus the system is highly variable in radio emission. It is unclear why it varies, and whether it emits from the star, the planet or an interaction between them. We propose to observe the system 5 times in Band 3 with uneven intervals in about 20 days, and a single observation in Band 6 with ALMA, both aiming to reach a sensivitiy of 18uJy. The detection or the non-detection will firstly give us crucial constrainst on the origin of radio emission, and will help to understand the varibility of radio emissions. A first detection of mm-wavelength emission will open a new window for the study of exoplanets, and provide important information about magnetic fields, and therefore planets' interior structure, habitability and atmospheric retention. Exo-planets Disks and planet formation 2019-01-12T03:07:32.000
310 2012.1.00988.S 0 The Cold Phase of a Hot Mode: Filaments and Feedback in Abell 2597 We propose an ALMA Band 6 observation of the central brightest cluster galaxy (BCG) in the rapidly cooling galaxy cluster Abell 2597 ($z=0.082$). Our goal is to obtain a spatially resolved map of cold gas structure and dynamics amid optical and X-ray cooling flow filaments, an arc of possibly jet-triggered star formation, and an AGN-driven multiphase (10^3-10^7 K) outflow. In a single pointing, ALMA can advance our understanding of the mysterious cold phase associated with these phenomena, each of which is a unique signature of unsolved problems relevant to galaxy evolution models at both early and late epochs. Our proposed CO(2-1) and mm continuum observation will test hot vs.cold accretion origins for the kpc-scale gas filaments in A2597, as well as the poorly understood mechanical interaction between a propagating radio source and its ambient cold molecular medium. ALMA is the only facility capable of discovering a spatially resolved AGN jet-driven molecular gas outflow in A2597, which we believe is likely given recently published multiwavelength evidence. Cold outflows in cool core galaxy clusters are an important and emergent focus of study that is largely enabled by ALMA's sensitivity and spatial resolution. This target is therefore ideal for Early Science, and would be an efficient demonstration of ALMA's breakthrough capabilities in a field with broad implications for galaxy evolution. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 2014-12-13T14:28:00.000
311 2016.1.00585.S 13 Giant factory caught contaminating the environment: dust and molecules expelled by eta Carinae Eta Carinae is one of the most massive stellar sources in the Milky Way; it entered the hall of fame of astronomy in the mid 19th century when it underwent a major outburst known as the Great Eruption. This event led to the ejection of at least ten Solar masses of material, now distributed in a bipolar nebula called the Homunculus. The material in the Homunculus is nitrogen-rich and carbon- and oxygen-poor, as expected for stellar matter after an interrupted CNO cycle: it provides us with a rare example of an ejecta that has not yet mixed with the ambient medium. Dust and molecules have formed out of this material, and recent APEX and Herschel observations have shown that the chemical composition of the molecular component reflects the peculiar elemental abundances of the Homunculus. Here, we propose to constrain the spatial distribution of the dust and molecular components using high resolution ALMA observations. These observations will constitute a fundamental step toward a complete understanding of the origin and the dust and molecular component around eta Carinae, that will have important repercussions for our comprehension of the latest stages of massive stellar evolution. Luminous Blue Variables (LBV) Stars and stellar evolution 2018-02-02T08:22:05.000
312 2019.2.00054.S 152 Understanding the Full Disk Life Cycle and the Beginnings of Planet Formation ALMA has greatly advanced our understanding of planet formation, yet we still lack a holistic view of the full disk life cycle in a single star-forming region, from the initial Class 0/I embedded stage (<1 Myr), to the Class II protoplanetary phase (1-5Myr), to the final Class III debris clearing stage (>5 Myr). Because planet formation is an ongoing process that likely begins early (<=1 Myr), obtaining this complete view is critical to understanding how planetary systems are assembled. Our team has completed ALMA surveys of the Class II and Class III disk populations in the Lupus star-forming region; here we propose an ACA survey of the Lupus Class 0/I sources in Bands 4, 6, 7, and 8 to construct robust SEDs and probe large spatial scales. These observations will be critical to our radiative transfer forward modeling to derive fundamental properties of these embedded disks, which we will compare to the protoplanetary and debris disk populations in Lupus. The end result will be the first complete view of the full disk life cycle in a single star-forming region with ALMA, providing much-awaited insights into the beginnings of planet formation. Disks around low-mass stars Disks and planet formation 2022-08-24T15:28:18.000
313 2019.1.01784.S 675 Knocking on the door of Large Lens Samples with ALMA Gravitationally lensed sources offer a unique window onto the Universe, by amplifying the background source both in flux and in angular size, and by probing the intervening matter. This allows large samples of gravitational lenses to statistically measure the cosmological properties of the Universe, especially since lens-selection in sub-mm relies solely on the background, lensed source. Here, we aim to use ALMA to test our state-of-the-art method for finding lenses hidden inside the lower-flux regimes of sub-mm surveys. We use the near-infrared VIKING survey to look for foreground, lensing galaxies, expected to be bright in these colours. Initial analysis finds our method works robustly, however we require high-resolution imaging to confirm this. We stringently select 86 potential lenses from 20 to 80 mJy at 500 micron, and require 18.7 hours to identify their lensing nature, a method verified by our Pilot program. Not only can these measurements verify our method, they can also be a first measurement of the lensing probability at low flux densities. Sub-mm Galaxies (SMG), Gravitational lenses Galaxy evolution 2022-06-15T21:45:33.000
314 2015.1.00369.S 48 The evolution of outflows from high-mass stars We have performed a deep continuum survey with the JVLA at 6 and 1.3 cm, towards a sample of 60 high-mass star-forming cores. These belong to 3 different types that we believe to correspond to different evolutionary phases: hot molecular cores (HMCs), cold molecular cores with mid-IR emission (CMC-IRs), and without mid-IR emission (CMCs). Indeed, we find that free-free emission is detected only in 1 CMC out of 18 (6%), whereas detection rates of 53% and 91% are obtained respectively for CMC-IRs and HMCs, consistent with an age increase from CMCs to HMCs. Since in most cases the cm continuum emission has spectral index of 0.2-1 between 5 and 22 GHz and jet-like morphology, we conclude that we have identified a sample of thermal jets from massive young stellar objects (MYSOs). This is ideal to study the evolution of jet/outflow systems in the early stages of high-mass star formation. Our goal is to resolve the molecular outflows associated with a selected sample of 10 CMC-IRs and HMCs, and determine their physical parameters. By comparing the properties of the outflows of the two sub-samples (CMC-IRs and HMCs), we will determine how the outflow properties change with time in MYSOs. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2017-08-22T21:17:43.000
315 2018.1.01006.S 282 Testing the Molecular Gas Thermometer: Mapping Irradiation Tracers in Two Helix Nebula Globules Planetary nebulae (PNe) present fundamental examples of astrophysical plasmas and shock processes, and they serve as essential testbeds for studies of high-energy irradiation of cold molecular gas. The unparalleled sensitivity and mapping capabilities of ALMA will allow us to directly image the molecular content of globules within the Helix Nebula, one of the nearest and best-studied molecule-rich planetary nebulae. We propose spatially resolved observations targeting globules in the lines HCN, HNC, and other key species. By determining gradients of molecular irradiation tracers along the length of the globule filamentary structures, we will establish the effects of UV and X-ray penetrating power on the molecular chemistry of the nebula. The results of these observations, in combination with those of our recent line survey, will exploit the heretofore untapped potential of PNe for purposes of investigating the impact of high-energy photon flux on the chemistry of cold molecular gas. Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) ISM and star formation 2020-01-08T15:54:00.000
316 2018.1.00548.S 18 A Dusty Starburst Galaxy Caught in a Heavy Bombardment? The circumgalactic medium (CGM) is the battlefield between gas inflows along cosmic filaments and outflows from galactic disks. How the CGM connects to star formation is one of the most pressing questions in galaxy evolution. Although intervening cool gas in the CGM leads to strong Ly-a absorption that is evident in the spectra of background QSOs, there are only a handful of detections of the galaxies that give rise to strong absorbers at z > 2. By providing sensitive spectral mapping, ALMA is revolutionizing this field. In Cycle 3, we identified the first association between a hyperluminous starburst galaxy and multiple strong HI absorbers at z ~ 2.7. The spectra of two background QSOs show consecutive Ly-a absorption spanning over 1700 km/s, indicating the existence of a 6-Mpc gas-rich overdensity. We propose deep band-3 observations to map out its spatial and kinematic structure in CO(3-2). By comparing the data with simulations, we will identify gas-rich subhalos of the starburst and check how long their bombardment could sustain the starburst. The observations will also shed light on the chemical enrichment of the CGM and the diverse gaseous environments in massive halos. Sub-mm Galaxies (SMG), Damped Lyman Alpha (DLA) systems Galaxy evolution 2020-01-17T02:26:56.000
317 2012.1.00001.S 6 The Molecular Medium in the Prototypical Barred Spiral NGC 1097 The goal of this proposal is to spatially resolve and map all the various dynamically distinct environments of a bar in the prototypical barred spiral NGC 1097 using the most common molecular gas tracers at 3mm. Our aim is to better understand the molecular gas distribution and kinematics in relation to the star formation activity, bar-induced gas inflow and accretion. Specifically we want to better understand how the star formation progresses in the bar. The two possible hypothesis that can explain the observed location of HII regions on the leading side of the bar dust lane are that either the star formation is dominated by a dense phase in the bar not reflected in the 12CO emission which is better described by a diffuse phase, or star formation occurs in spurs on the trailing side of the bar. The observations proposed here will map the full bar in 12CO and half of the bar in the other common 3mm tracers (HCN, HCO+, 13CO) to determine the phase of the molecular gas along and across the bar dust lane. We will also study the spurs and determine how the density and kinematics (or local shear) controls the star formation activity. We will compare this to the bar end and the circumnuclear and inner rings. We will also use the high resolution an sensitivity data to constrain the gas inflow and accretion rates by directly comparing the observed kinematics to hydrodynamic and N-body simulations. Starbursts, star formation, Spiral galaxies Active galaxies 2016-11-08T02:13:50.000
318 2016.1.00593.S 43 Hot water from the inner 25AUs of the Class I source SVS13-A The origin of terrestrial water is still a source of intense debate. A key element to shed light on it, is how water evolves with time in proto-Sun analogues. Specifically, two aspects are crucial: (1) the amount of water in the planet formation region (~ tens of AU) and (2) its deuterium fractionation. While water has been imaged in a few low-mass Class 0 sources, only single-dish observations (e.g. Herschel) exist towards more evolved Class I to Class III sources, and no detection at all of HDO. Recently, we detected seven HDO lines with upper level energies up to 800 K towards the Class I source SVS13-A. A non-LTE analysis provides severe constraints on the gas emitting size (~0.2", i.e. 48 AU), temperature (150 K) and density (3 10^7 cm-3). No H2^18O emission has been detected and the lower limit to the HDO/H2O does not help to understand whether it decreases from Class 0 to Class I, as we recently found for CH3OH and H2CO on the same source. We propose here new ALMA high spatial resolution and high sensitivity observations of HDO and H2^18O towards SVS13-A with a twofold goal: reveal the structure of the gas of emitting the hot water, and estimate its deuterium fractionation. Astrochemistry ISM and star formation 2018-12-08T21:20:28.000
319 2019.1.00407.S 33 Connecting molecular gas properties of high-redshift galaxies observed in absorption and emission Detailed information about the neutral and molecular gas-phase of the diffuse interstellar medium (ISM) in high-redshift star-forming galaxies can be obtained from absorption studies of gamma-ray burst (GRB) absorbers. Here we propose an ALMA survey for CO emission in a sample of high-redshift GRB host galaxies, which have been specifically selected based on the presence of strong H_2 absorption. We propose to use the Band-3 receiver to target the CO(3-2) emission line from this pilot sample of three GRB host galaxies at z~2-3. Our objectives with this proposal are 1) to search for molecular emission features from a sample of the strongest H_2-selected GRB host galaxy absorption systems, 2) to derive molecular gas masses from the CO line emission, and 3) to connect the molecular gas properties of these particular absorbers observed in absorption and emission. This pilot survey is the first step to establish a link between the detailed information obtained from absorption-line studies of the molecular gas in galaxies at the peak of cosmic star formation to that inferred from emission. Damped Lyman Alpha (DLA) systems, Gamma Ray Bursts (GRB) Cosmology 2021-03-27T14:04:28.000
320 2016.2.00027.S 4 Complex organic molecules in UV irradiated gas: The Horsehead PDR Despite the observational efforts we are still far from understanding how chemical complexity increases in space. In order to answer this question it is crucial to benchmark models with sources that have simple geometries, known physical conditions, and where the different grain surface and desorption processes can be isolated. The relatively low UV-illumination (thus cold grains) Horsehead photodissociation region (PDR) offers a unique laboratory to study the formation of complex organic molecules (COMs) because contrary to protostars, ice mantles can only desorb non-thermally. We know that photo-desorption is an efficient mechanism to release COMs from the ices, and that there is an efficient top-down chemistry operating, leading to enhanced charbon chains and COM abundances in this PDR. However, the relative contribution of the different photo-processes remains poorly constrained, and the dominant formation pathways of some species, particularly CH3CN and CH3NC, are unknown. We propose to use the ACA to image the emission of 7 COMs in the Horsehead PDR to investigate their dominant formation pathways and characterize the role of FUV photons in their formation. Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) ISM and star formation 2019-03-09T20:05:19.000
321 2012.1.00523.S 5 Measuring the Infrared Emission and Dynamics for a Population of Primordial Galaxies We propose to observe the dust continuum and CII line emission for an ultraviolet flux limited sample of 10 spectroscopically confirmed L>L_* "normal" galaxies at 55 from Keck and VLT along with the wealth of multi-wavelength data in the proposed COSMOS field ensure the physical properties and local environment of these sources is known. Lyman Break Galaxies (LBG) Galaxy evolution 2015-04-01T12:58:21.000
322 2019.1.00086.S 60 BOPS: B-field Orion Protostellar Survey Interferometric polarization observations have found that magnetic fields play an important role during the star formation process. However, their relative significance in their environment and their role in stellar multiplicity remains poorly understood. The TADPOL survey represents the largest polarization survey for low-mass protostars (~30 sources), but these sources were a variety of ages and in diverse star-forming environments at various distances. We want to improve significantly on the TADPOL survey by observing a factor of two more sources within a single region with better sensitivity. We will observe 870 um dust polarization toward 57 young protostars in the Orion molecular cloud on scales of 400 to 2000 au. At these scales, the observations will uniformly probe the magnetic field structure in envelopes around the protostars. We will also map CO(3-2) outflows to establish the angular momentum axes of the protostars. Combined with ancillary data, we will investigate the origin of stellar multiplicity and understand the role of magnetic fields during the star-forming process. This survey will be the most statistically robust, high resolution polarization survey to date. High-mass star formation, Low-mass star formation ISM and star formation 2022-05-06T00:00:00.000
323 2015.1.00456.S 19 Gas Dynamics and Clump Scaling Relations in High-Redshift SMGs We propose band 7 observations of the [C II]157um emission and dust continuum in four z~4.5 sub-mm galaxies (SMGs) at the highest spatial resolution (C36-7; 0.04") available in Cycle 3. These SMGs are selected from our cycle-0 ALESS and cycle-1 ALMA-S2CLS surveys. Our goals are to measure the gas dynamics and the distribution and intensity of star-formation within these galaxies on ~200pc scales. Our science goals are to search for and measure the sizes, luminosities, velocity dispersions, and spatial distribution of the star forming regions within the ISM and relate their properties to the underlying gas disk dynamics and gas pressures. Addressing how the (in)stabilility of high-redshift, gas rich disks controls the formation and properties of star-forming regions is critical for developing models of galaxy formation, in particular to determine whether the prescriptions developed to describe star-formation processes at z = 0 are applicable in the dense and rapidly evolving ISM of gas rich, high-z galaxies. All of our targets have already been detected in continuum and in [C II] with ALMA from our previous observations in cycle 0/1. The total time request is 6.4 hours. Sub-mm Galaxies (SMG) Galaxy evolution 2017-04-13T13:26:44.000
324 2018.1.01395.S 10 Witnessing the early stages of the formation of Super Star Clusters in the nucleus of the nearby starburst galaxy NGC253 We have used 0.2" ALMA images of the HC3N vibrational excited emission (HC3N*) to reveal the Super-Hot Core (SHC) phase associated to Super Star Clusters (SSCs) in the nearby starburst galaxy NGC253. HC3N* emission is a direct probe of unobscured mid-IR emission since it is radiatively pumped by the dust heated by the protostars. The detected 7 unresolved SHCs with temperatures >230 K and high densities are tracing the proto-SSC phase just before massive stars ionize their surroundings. We estimate that proto-SSCs account for more than 1/3 of the total luminosity of the galaxy. However, our estimates are still very rough and better resolution and sensitivity are required to make robust estimates of the luminosities. We propose to image the nucleus of NGC253 in the HC3N* emission with 0.025" resolution and enough sensitivity to make accurate measurements of sizes, temperatures, masses and luminosities for all SHCs, and to derive temperature and density profiles for some of them. This data will provide a firm estimate of the contribution of the proto-SSC phase to the global star formation, and to test the predictions of the proposed scenarios for the formation of SSCs. Starbursts, star formation, Galaxy chemistry Active galaxies 2021-02-12T18:33:55.000
325 2011.0.00273.S 0 SN87A: A Unique Laboratory for Shock and Dust Physics SN987A is a unique laboratory to study shock physics and particle acceleration, cosmic dust and element production. Despite intense observation over the last 25 years, outstanding questions remain which only ALMA can address, and signficant discoveries can already be made in Cycle 0. We propose to image the remnant of SN1987A in the four available bands, spanning a critical transition wavelength range: At 100GHz SN1987A's flux is dominated by nonthermal emission from a shocked circumstellar ring, but by 690GHz the flux is predominantly thermal emission from dust in the central debris. The proposed observations will constrain models for relativistic particle acceleration in shocks. They will yield the first resolved images of the supernova debris at sum-mm wavelengths. They have the potential to discover molecular line emission from both the inner debris and from the circumstellar ring, and to find evidence for emission by a central compact object. The observations will be path finders, establishing a synoptic baseline for a major campaign with the full array. Supernovae (SN) ejecta Stars and stellar evolution 2014-02-07T19:31:00.000
326 2019.1.00801.S 66 HCN formation in the innermost region of O-rich AGB stars Asymptotic Giant Branch (AGB) stars are divided in two types, O-rich or C-rich. In the firsts, carbon atoms are mostly locked into CO and the chemistry is essentially oxygen-based. Oppositely, for the seconds, the chemistry is largely carbon-based for the same reason. This is true but not as simple. Various carbon-based molecules hava been observed in O-rich stars, and inversely, proving that AGB stars are far from thermochemical equilibrium. Non-equilibrium processes invoked are, either pulsationally-driven shocks in the inner wind, or photochemistry driven by the penetration of galactic UV photons. To date, we do not know which one is involving, or dominating, but we predict different behaviours, e.g. formation of unexpected molecules very close to the photosphere of the star in the first case, within ~5 stellar radii, or a bit further in the second. To discriminate, we propose to observe, in 3 O-rich AGB stars (R Leo, R Crt and IK Tau), the formation region of one of those unexpected molecules, namely HCN, with a high angular resolution of 50 mas. These data will provide a numerous number of constraints to the current AGB models and shed light on their complex chemistry. Asymptotic Giant Branch (AGB) stars Stars and stellar evolution 2022-11-23T00:26:16.000
327 2016.1.00264.T 1 Revealing the magnetic structure of compact jets in Galactic black hole X-ray binaries One of the biggest questions left in high energy astrophysics is the mechanism to form the relativistic jets from accreting black holes. Here we propose to carry out first TOO polarimetry of transient Galactic black hole X-ray binaries in the mm band, to study the magnetic field structures of compact, steady jets ubiquitously seen in low mass accretion rates. To trigger the observations, we monitor the X-ray lightcurves and spectra of our targets using the Japanese all-sky X-ray monitor MAXI. The ALMA's high sensitivity enables us for the first time to detect the polarized synchrotron component in the mm band and to constrain the magnetic field configuration at the base of the jets. We are also preparing for simultaneous multi-wavelength observations including X-ray, near-infrared and optical bands. They are expected to provide great synergy with the ALMA observations, by allowing us to reveal the structure of the inner accretion disk, as well as to estimate the magnetic field strength and energy distribution of electrons at the jet base. Black holes, Transients Stars and stellar evolution 2018-03-01T20:37:23.000
328 2011.0.00779.S 0 Characterizing Io's atmospheric composition and circulation v3 Jupiter's moon Io is the most volcanically active body in the solar system and has a very thin and spatially variable atmosphere, mainly composed of SO2. The goal of this proposal is to adress several aspects of the atmosphere that are not well characterized : the nature and abundance of the minor species, the replenishment sources for SO and SO2, and the atmospheric circulation (wind). To bring unprecedented constraints on these questions, we propose to observe a rich portion of band 7 with the extended configuration and a fine spectral resolution. The excellent available sensitivity will allow to search for expected yet undetected volcanic species such as KCl, S2O, SiO and CO, for which the abundance measurement will put strong constraints on the volcanic regimes. Simultaneously, the strong lines of main species SO2 and SO will be mapped with an improved spatial resolution, with the objective to relate their spatial distribution to their possible respective replenishment mechanisms. Finally, we will measure Doppler-shifts on the strongest line to retrieve the best observation of the atmospheric wind-field. Io's atmosphere circulation has only been observed once so far, and the proposed ALMA observations are expected to provide a radical improvement on the wind measurement. Solar system - Planetary surfaces, Solar system - Planetary atmospheres Solar system 2014-02-11T21:21:00.000
329 2017.1.00042.S 141 Arp 220 Nuclear Disks at 0.027-0.05'' Resolution We propose to complete our ultra-high resolution imaging of Arp 220 to resolve the gas structures and dynamics in the two nuclear disks. In ALMA Cycle 3, our project 2015.1.00113.S was scheduled for both long and short baseline imaging in the CO (1-0), (2-1) and (3-2) lines. This project was A-ranked but so far we have received only the CO (1-0) imaging. Although this project was carried over to Cycle 4, we do not know if it will be completed in Cycle 4; here we submit the uncompleted parts of the original project. In Cycle 5 which provides longer baselines, we also propose to augment the Cycle 3 CO (1-0) resolution by a factor 2 to 0.05'', and to obtain the remaining high resolution imaging in the CO 2-1 which will yield 4x higher resolution (0.027'') than the existing CO (1-0). This spectacular imaging will resolve physical radii down to 5 pc within the central gas concentrations and well within the sphere of influence of the putative super massive black hole. In addition, the CO line ratio and excitation analysis in Arp 220 an analog of high z starbursts and SMGs will provide a vital foundation for interpreting observations of high z mergers. Starbursts, star formation, Merging and interacting galaxies Active galaxies 2020-12-23T14:37:22.000
330 2019.A.00036.S 10 Unveiling the outflow mechanisms in transitional millisecond pulsars: the ultimate observing campaign of PSR J1023+0038 The discovery of three millisecond pulsars that swing between an accretion and a rotation powered state has challenged our comprehension of the evolution of accreting neutron stars in low mass X-ray binaries. We are coordinating the most extensive ever, strictly simultaneous, multiband campaign of the transitional millisecond pulsar PSR J1023+0038 during its current peculiar X-ray sub-luminous accretion disk state. We propose to observe this system with ALMA simultaneously with other telescopes to: i) assess whether the mm emission displays similar variability as observed at lower frequencies; ii) determine the spectral slope in the radio-mm-near infrared domain to probe the presence of a jet (and determine its properties) and to gain insight into the role of a putative pulsar wind in driving radio flares. The ALMA observations will be crucial to nail down conclusively the connection between mass accretion and ejection in this system and in the transitional millisecond pulsars in general. This ultimate campaign will advance our knowledge on the details of the process by which neutron stars evolve from the initial accretion state to the final rotation-powered radio pulsar state. Pulsars and neutron stars Stars and stellar evolution 2022-01-27T09:56:03.000
331 2016.1.00201.S 1 Magnetohydrodynamic mechanisms of jets in the solar chromosphere Solar spicules are one of the jet phenomena regularly observed all over the solar limb in the chromosphere, that is an atmospheric layer between the visible surface, i.e. the photosphere, and the corona. Spicules are a manifestation of dynamic interaction of thermal convection below the surface, shock waves, and magnetic field. Quantitative understanding of chromospheric jets is important not only for understanding of the chromospheric phenomena themselves but also for the energy transport into the corona and the solar wind. Our observation target in this proposal is spicules in coronal holes on a solar limb. The observation would be done by the sit-and-state mode with C40-3 configuration in Band 6 and Band 3. The required duration is 2 hours with cadence of 2 sec for each band. Through these observations, we are going to try to detect (1) for more frequent ``ordinary spicules", shock waves at the feet that are direct driver of the jets, (2) for taller jets, a horizontal motion of the chromospheric plasmas as a manifestation of the twisting Lorentz motion. These features are predicted by our MHD numerical simulations. The Sun Sun 2018-07-11T16:43:36.000
332 2015.1.01268.S 1 ALMA long baseline observations of DGTau We propose Band 6 continuum observations of DG Tau at an angular resolution of 0.04"(5.6 AU). Our aim is to search for another example of concentric ring-gap structure in a protoplanetary disk, similar to those found around HL Tau by the long baseline campaign. Although several mechanisms that account for the ring-gap structure have been proposed, it is very difficult to identify which mechanism is the case based on a single example. It is also unknown whether the formation of such structure is a universal phenomenon in the early stage of classical T Tauri stars. To answer these questions, we should look at another object that enables us to make comparative studies with HL Tau. DG Tau is a promising target, bearing striking similarities to HL Tau. Even if no concentric ring-gap structure is found in DG Tau, the comparisons with HL Tau will give us informations about the conditions for the formation of such structure. The proposed observations will be an important step towards understanding of the origin of concentric gaps that should be deeply related to the formation of a planetary system. Disks around low-mass stars Disks and planet formation 2017-03-02T13:42:23.000
333 2023.1.00600.S 0 A hybrid approach to measure the 3D infall kinematics in an isolated protosellar core Gravitational infall of gas and dust is a key process that governs the evolution of star formation. Recent discoveries of asymmetric infalling filaments challenge conventional models of infall and rejuvenate the measurements of 3D infall kinematics in protostellar envelope. BHR 71 IRS 1, an isolated Class 0 protostar, presents an ideal test-bed to study the infall process along several directions. Using two well-established methods, we would probe the infall kinematics along the line of sight and the streamers, constructing the kinematics radially and directionally. The redshifted absorption is an unambiguous signature of infall, which has been detected in HCO+ 4-3 toward BHR 71; however, its interpretation heavily relies on modeling. The same observations also hints at three distinct infalling streamers, but the optically thick emission of HCO+ 4-3 prohibits precise kinematics measurements. Thus, we propose to emipirally measure the infall along the line of sight using highly excitation HCO+ lines and trace the infall kinematics along the streamers using the optically thin H13CO+ line. This program will provide the true 3D infall kinematics for the first time. Low-mass star formation ISM and star formation 2024-11-07T14:01:31.000
334 2017.1.01181.V 0 The light-day scale structure of an extragalactic jet: 1 mm VLBI observations of Centaurus A Joint VLBI observations with phased-up ALMA and the Event Horizon Telescope (EHT) at 1.3 mm provide the required sensitivity and angular resolution to study the jet formation region of the closest radio-loud galaxy, Centaurus A (Cen A) at scales of less than 1 light day. Due to its relative proximity (3.8Mpc), this source is a unique laboratory for investigating jet formation, collimation, and the origin and mechanism(s) of high-energy emission on the smallest scales. At a declination of 43deg, Cen A has only been poorly accessible for mm-VLBI until recently. Here, we propose a second EHT+ALMA observation to improve the uv-coverage (4h uniformly spread over different GST ranges) and to benefit from the boost in sensitivity due to 64 Gbps recording. Together with our first EHT+ALMA observation from April 2017, this allows us to confirm structure and study the inner jet evolution. We will compare the observations with predictions from dedicated Special Relativistic Magnetohydrodynamics (SRMHD) simulations, which are based on low-frequency VLBI data of Cen As jet, as well as large-scales 3D GRMHD simulations and semianalytical models. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 2021-05-31T11:44:50.000
335 2016.1.00297.S 55 Search for Interstellar Pyrimidine Many interstellar complex organic molecules are known to be prebiotically important and have essential functions in terrestrial biochemistry. Pyrimidine, the building block of nucleic acid, has been detected in meteorites and is hence a key molecule for astrochemistry and astrobiology. Given the fundamental importance of interstellar pyrimidine, we thus propose to observe nine most favorable pyrimidine bandheads and five strong low-J doublets in the Orion KL hot molecular core with ALMA in Band 7. Although the formation of prebiotic molecules in extraterrestrial environment and their contribution to the origin of life remains unsettled, the connection between interstellar organic chemistry, meteoritic pyrimidines, and the emergence of life on early Earth would be strengthened with the discovery of interstellar pyrimidine. Astrochemistry ISM and star formation 2018-05-16T09:45:30.000
336 2017.1.01628.S 22 Searching for CO-dark H2 gas in radio jets Our recent discovery shows that cosmic-rays (CRs) destroy CO by converting it to CI while the H2-gas remains unaffected and challenges the widely used CO-to-H2 method in extreme environments, especially in extragalactic outflows in radio jets. These are characterized by strong magnetic fields with high densities of CRs, which makes the H2 gas to be CO-poor and CI rich. This can potentially make H2 outflows of extreme environments (AGN and starbursts) appear CO-dark. Recent ALMA detections of CO in galactic outflows indicate that H2 can exist in such extreme environments. Therefore, we propose to carry out CI 1-0 observations in the radio jets of Miknowski's Object and M87, where CO lines have been detected. We aim at i) determining the degree of CI-CO concomitance, ii) estimating the H2 gas mass in each case and iii) estimating the star formation efficiency along the outflow, to compare with the CO-based measurements. This will be a key experiment for testing our predictions that CI in both radio jets will be much brighter than in CO lines under normal conditions of H2-gas. If confirmed, it will open a new window of H2-gas detection in radio jets under extreme conditions. Outflows, jets and ionized winds ISM and star formation 2019-07-13T10:04:37.000
337 2012.1.00402.S 0 Exploiting the synergy between early ALMA and VLT/AO-IFU For several years it has been a challenge to study high-z star-forming galaxies using both optical and sub-millimetre spectroscopy -- a problem mainly induced by typically large dust extinctions in these systems. In this work we propose a pilot extra-galactic experiment to forge a synergy between the ALMA and VLT telescopes. We use a uniquely suited z=1.4608 star-forming galaxy selected from the HiZELS coverage in the UDS field. It is located near a bright star that aided adaptive optics (AO)-assisted integral field unit (IFU) Halpha imaging with SINFONI (0.15''~kpc-scale resolution). The IFU imaging revealed large ionised gas complexes in a rotating disk (approximately 50% of the light is in the form of clumps), allowing an estimate of inclination, asymptotic rotation speed and dynamical mass. We propose to use ALMA to follow-up these observations and measure the available reservoir of molecular gas mass via the CO(2-1) emission (in Band-3) and the spatial distribution of the cold dust (in Band-7). ALMA observations at kpc-resolution, matched to the spectral imaging, will provide key insights into the drivers of the star-formation (and its efficiency) at z~1.5, near the peak of the cosmic star-formation activity, where galaxies were assembling most of their stellar mass. Starburst galaxies Active galaxies 2015-08-08T12:37:34.000
338 2019.1.01138.S 7 First characterisation of a multi-planetary system at the stage of formation Many questions regarding planet formation are still open, in particular how material is accreted from the protoplanetary disk onto the forming planet through its circumplanetary disk (CPD). PDS 70 is a unique source to investigate such processes as it hosts two planetary companions within an inner cavity. These sources, PDS 70b and c, were robustly detected with SPHERE (infrared) and MUSE (Halpha). The analysis of ALMA Band 7 observations, at an angular resolution of 70 mas, indicates continuum emission at the location of the planets and represents the very first detection of a CPD. However, higher resolution observations at 30mas are required to confirm the presence of these two CPD and spatially resolve the CPD around PDS 70c from the edge of the continuum ring. In addition, substructure within the dust ring and a peak of CO emission offset from the bulk Keplerian profile strongly suggests the presence of a third companion of the disk. The requested observations would also allow for the characterization of substructure within the dust ring, required to confirm the presence of a third companion. Exo-planets Disks and planet formation 2023-08-17T22:41:09.000
339 2013.1.00271.S 10 Sub-kpc Kennicutt-Schmidt star formation law in luminous infrared disks We propose to obtain sub-arcsec resolution CO(2-1) ALMA images of two nearby Luminous Infrared Galaxies (LIRGs) covering the high-density (2-20 Msun/yr/kpc^2) regime of star-forming clumps. The galaxies are representative of the class of extended (~ 3 kpc) luminous star-forming rotating disks. Accurate star formation surface densities on ~ 0.2 kpc scales already exist based on our Pa-alpha HST imaging and Br-gamma SINFONI/VLT maps. The proposed observations will provide a direct measurement of the molecular gas surface densities of the star-forming clumps (and inter-clump medium) on scales of hundred parsec. Our extinction-corrected star formation and the ALMA-derived molecular gas densities will determine for the first time the Kennicutt-Schmidt law on sub-kpc scales for LIRGs, i.e. sampling the regime of large SF regions with high star formation surface densities. This important class of galaxies that are among the most luminous starbursts in our nearby Universe, also represent the closest analogs of the high-z clumpy star-forming extended disks. Thus the proposed observations bridge the gap between local spirals and star-forming galaxies at cosmological distances. Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Galaxy evolution 2016-04-22T11:59:55.000
340 2022.1.01030.S 153 Pinpointing the brightest, and yet elusive, submillimetre galaxies. The bright tail of the submillimetre population is poorly understood, largely due to the intrinsic rarity of these ultra-bright galaxies with source abundances ~0.5-5 galaxies per sq. degree. We target 17 of the brightest ever found (S_850~>20mJy) SMGs, facilitated by the uniquely large area of new SCUBA2 850um observations in XMM-LSS. Our primary goals are to determine the relative contribution of source blending and gravitational lensing to the bright-end of the 850um number counts, and to robustly measure the redshift distribution for this highly-luminious population. These key observables are currently unexplored for the ultra-bright SMG population and will provide powerful constraints for galaxy formation models, which struggle to reproduce current observations. With ALMA we can robustly detect ALMA counterparts for all these single-dish sources in ~35 minutes, allowing us to efficiently constrain the multiplicity fraction. With accurate positions for the ALMA counterparts we can pin-point optical/near infrared counterparts, allowing us to derive photometric redshifts and physical properties for these SMGs via SED fitting, to uncover the true nature of this unique population. Sub-mm Galaxies (SMG) Galaxy evolution 2023-10-25T15:27:51.000
341 2022.1.01618.S 0 Revealing the interaction between the non-thermal point source N3 and molecular gas in the Galactic center The non-thermal radio point source N3 is a black hole (BH) candidate near the Galactic nucleus. A peculiar compact molecular cloud (N3 cloud) is associated with N3 in appearance. Although the high temperature and broad velocity width of the cloud are suggestive of an interaction with N3, the actual relation is unclear. N3 could be an intermediate-mass BH (IMBH) with a few ten thousand solar masses that gravitationally interacts with the ambient molecular gas. In order to reveal the true nature of N3 and the N3 cloud, we propose high-resolution molecular line and continuum observations in ALMA Band 6 and 7. The principal objective is to investigate the internal kinematics and physical conditions of the N3 cloud. The possible origin of N3 is (1) a massive IMBH, (2) a micro-blazar, or (3) a background AGN. The ALMA images should enable us to distinguish which scenario is the most plausible for N3 and the N3 cloud. This project has a potential to bring new perspectives on BHs and molecular clouds in the Galactic center. Galactic centres/nuclei Active galaxies 2024-07-31T19:16:37.000
342 2022.1.00519.S 0 Resolved, Spatially Complete Maps of Dense Gas Tracers in LMC Clouds We request 11.1h of main array time to obtain sensitive (64mK) 12m+7m+tp maps of the emission from Band 3 'dense gas tracers' at 1pc+0.8km/s resolution across the full CO-emitting extent of five molecular clouds in the Large Magellanic Cloud. Our target clouds have existing ALMA maps of the CO isotopologues and span a range of star formation activity. We will use the data to study the spatial organization and velocity field of the dense gas within each cloud, the distributions of intensity, linewidth and line profile shape parameters for each tracer, and their relationship to the physical properties of CO-emitting structures. The proposed maps will build a bridge between highly resolved Galactic work and kpc-scale results from more distant systems, a key to understanding the physics that drives extragalactic scaling laws relating `dense gas' and star formation. Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds ISM and star formation 2024-10-25T14:47:28.000
343 2019.1.01611.S 20 Resolving the kinematic structure of galaxies in the first 800 million years of cosmic time We propose deep, high angular resolution band 6 observations of [CII]158mum in two normal star-forming galaxies at z~7. These galaxies were recently spectroscopically confirmed through [CII] (at low angular resolution) and they are currently two of the four brightest known [CII] emitters in the Epoch of Reionization. With our observations we will derive the kinematics of these galaxies in a very early stage of galaxy formation and we will test if these distant systems are forming their stars in well-ordered, gas rich disks or if the sources are dominated by turbulent gas motion. This analysis will reveal if smooth accretion from the cosmic web or major mergers contribute most to the build-up of stellar and baryonic mass at z~7. We will furthermore investigate the morphology of the gas and dust and determine the offsets and spatial extend of these ISM components with respect to the stars that are visible in the rest-frame UV. Lyman Break Galaxies (LBG) Galaxy evolution 2023-01-21T00:00:00.000
344 2016.1.00383.S 31 The Massive Protostellar Maelstrom of NGC6334I-SMA1: a Hot Multi-Core Tracing a Proto-Multiple OB System? NGC6334I is a nearby (1.3 kpc) example of a deeply-embedded massive protostellar cluster. At the center is a Trapezium-like arrangement of four millimeter sources, two of which are prolific hot cores (SMA1 and SMA2). Our initial ALMA observations in Band 6 with a 250 AU beam have resolved SMA1 into at least four continuum components separated by ~1000 AU. This configuration suggests a "hot multi-core" in which four seeds appear to be accreting from a common gas reservoir at the core of the protocluster, possibly leading to a proto-multiple system. Two of them show compact line emission in CH3CN J=12-11, K=10 (782K above ground) while three of them appear in absorption in the low K lines. In order to further resolve the multiplicity and model the gas surrounding each protostar, including the velocity components, temperature, and density, we propose matched resolution (100 AU) imaging of a wide range of diagnostic transitions in Bands 4 and 6. In conjunction with existing VLA 1.3 cm and 7 mm images of comparable resolution, the continuum data from the line-free channels will allow us to also model the SEDs, and hence the dust mass around the individual protostars. High-mass star formation ISM and star formation 2018-10-31T21:37:09.000
345 2013.1.01213.S 21 Testing the reversal of the star-formation-density relation in a high redshift cluster We propose to measure the continnium and CO line fluxes for the star-forming galaxies at the center of cluster XCSJ2215 at z=1.46. The four first priority sources within 0.25Mpc radius of the cluster are detected in the SCUBA-2 850um image, and their counterparts in Spitzer IRAC and/or MIPS 24um images are confirmed cluster members. We attempt to examine the dynamics, the molecular gas mass, the star formation efficiency, and the dust to gas ratio of these cluster galaxies from the CO(2-1) line observation. In addition, the continnum observation at band 6 is required to solve the multiplicity issue, and to detect less star-forming galaxies indicated from the [OII] emissions. Starburst galaxies, Sub-mm Galaxies (SMG) Active galaxies 2016-11-18T17:57:04.000
346 2017.1.01687.S 65 Characterizing the solar nebula analog MP Mus The number of nearby, primordial circumstellar disks is very small, which significantly limits our current understanding of their evolution. We propose to observe the evolved disk around the nearby (100 pc) solar analog MP Mus, a source very similar to the famous TW Hya disk that is still mostly unexplored. Despite its age (8-15 Myr), MP Mus is surrounded by a gas and dust rich disk that may have a large cavity, as suggested by its SED and previous coronagraphic observations. We propose to perform a comprehensive characterization of this target with spatially resolved observations of its dust continuum emission at bands 7 and 4, together with 12CO(3-2) and 13CO(3-2) observations. These data will: 1) reveal the dust distribution of the disk around MP Mus and unambiguously identify the presence of a cavity, 2) probe dust growth and migration at different locations in the disk, 3) determine the gas distribution and mass, and 4) accurately estimate its gas-to-dust ratio. The proximity, age, and characteristics of MP Mus make it a perfect laboratory to better understand disk evolution and planet formation. Disks around low-mass stars Disks and planet formation 2019-07-23T14:11:45.000
347 2021.A.00023.S 40 A Pilot Study for the Far-IR Confirmation of the Oldest Galaxies Observed by JWST We propose ALMA observation of the recently discovered galaxy candidate, GLz11 at z=10.74, from the JWST ERS program. JWST will routinely discover these early galaxies and can do a census of similar z>10 galaxies to understand the first galaxy formation. ALMA is the only instrument with the sensitivity to detect the FIR continuum and fine structure from such an object, and has a strong synergy with the JWST observation to study the high-redshift galaxy formation. The observation of FIR SED including cooling line is very important to measure the spectroscopic redshift and constrain the physical parameters from SED modeling in terms of constraining dust content to break the age-dust degeneracy. Our program will observe the FIR peak of GLz11 with spectral window set up covered by 3 Science Goals such that 88.63micron [OIII] emission line is included in the sufficient redshift range (z=10.30-11.21) for spectroscopic redshift confirmation. The proposed observation has the very real potential to both verify a key science program for the JWST by confirming an extreme redshift galaxy, and demonstrate the importance of ALMA in the JWST era for studying the first galaxies in the Universe. Galaxy structure & evolution Galaxy evolution 2022-09-23T22:44:06.000
348 2018.A.00065.T 29 Molecular gas in the immediate vicinity of GRB 190829A, within a massive dusty galaxy GRB190829A, detected on 29-August-2019 at z=0.079, is one of the closest GRBs ever discovered. However, unlike all other identified GRBs at z<1, GRB190829A is located in the metal-rich ISM of a massive galaxy, with its spectral properties indicating an over-dense environment, consistent with the hypothesis that GRBs form in regions with high star formation density. The GRB afterglow has been detected at 90 GHz with a flux density of 6.3 mJy. This provides the exciting opportunity to probe the molecular gas, the fuel for star formation, in the immediate vicinity of the GRB, by carrying out a search for CO and HCO^+ absorption. We propose here to use the ALMA Band-6 receivers to search for redshifted CO(J=2-1) and HCO^+(J=3-2) absorption against the GRB afterglow, to trace the conditions that resulted in the formation of the GRB. The time criticality of this proposal is because the observations have to be done within the next few days, while the mm-wave flux density of the GRB afterglow is sufficiently high for the proposed absorption spectroscopy. We request a total of 3.2 hours with the Band-6 receivers, including all overheads and calibration. High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2020-07-16T03:22:14.000
349 2017.1.00889.S 139 The feedback effect from massive stars on the fragmentation of dense structures The relative importance of the mechanisms that shape the internal structure of the star forming clouds is one of the most important questions in the star formation community. The extraordinary capabilities offered by ALMA will allow us to obtain detailed map of the dense gas down to size scales ~0.02 pc, adequate to resolve the structures associated to dense cores and complex filamentary structures. We propose to observe the dense gas at 1 mm over the two different regions located in the Carina Nebula already observed at 3 mm with ALMA Cycle 4. We will use these maps to investigate the role that external pressure plays on determining the densest components inside the diffuse medium in these clouds. The stability status of the identified structures will be used to assess whether these are supported by external pressure, and at which scale the gravity becomes the dominant force. Detailed comparison of the distribution of the dense gas and the location of young stellar objects will shed light on the dependence of the star-formation threshold on the external pressure in these clouds with different level of impact of stellar feedback. High-mass star formation ISM and star formation 2020-06-21T00:00:00.000
350 2013.1.00532.S 18 The Dense Gas Fraction and Its Dependence on Galactic Environment In order to formulate a general star formation theory, the underlying physics that govern star formation processes within galaxies must be understood. Our recent results on extragalactic Giant Molecular Cloud (GMC) populations imply that the internal structure and organization of molecular gas strongly depends on galactic environment - as does their star formation efficiency (SFE), though with different dependencies. Recent studies suggest that the SFE is set by the dense gas fraction and not the global molecular reservoir. Thus, we propose to map the dense gas fraction of massive GMCs (at 70pc(=2") resolution) in the nearby spiral galaxy M74 with ALMA. The dense gas fraction will be determined using several 3mm tracers (low to high density: 12CO, CS, HCO+, 13CO, C18O, HCN, HNC). These tracers will additionally probe the excitation conditions (HCO+, HNC, HCN, 12CO) and independently estimate the CO-to-H2 conversion factor (via the (1-0) transitions of 12CO, 13CO, C18O plus 12CO(2-1)). The requested observations will cover the same area as already mapped in CO(2-1) by our Cycle 1 program that will characterize the general GMC population and the different galactic environments. Giant Molecular Clouds (GMC) properties ISM and star formation 2016-02-27T15:12:41.000
351 2013.1.00041.S 10 Star Formation, Shocks, and AGN in a Pre-Starburst Galaxy Collision We propose an ALMA CO(1-0) map plus three HCN(1-0) and HCO+(1-0) pointings of the pre-starbust interacting galaxy pair IC 2163 and NGC 2207. CO will trace the total molecular gas distribution and kinematics. HCO+ and HCN will spatially resolve excesses of dense gas to relate to nuclear flows, turbulence, large-scale shocks, and local star formation rates. Line ratios in these AGN and AGN-free nuclei will probe the link between dense gas reservoirs, nuclear star formation, and black hole activity. Starburst activity in galaxy mergers can be driven by nuclear flows, gas fragmentation, and large-scale shocks, and can be balanced by feedback from young stars and black holes. The role of these mechanisms in boosting star formation efficiency in mergers is poorly understood. This galaxy pair offers an ideal laboratory to study these phenomena. Their grazing collision has increased gas turbulence, produced Super Star Clusters and shocks, and fueled nuclear activity. It is well observed and modeled, with HST optical, SST infrared, XMM X-ray, VLA 21 cm emission and 6 cm and 20 cm continuum, Herschel PACS and SPIRE broadband data, and simulations fitting over 30 features. Starbursts, star formation, Merging and interacting galaxies Active galaxies 2016-08-05T17:18:57.000
352 2019.1.00597.S 10 Cold gas on the red sequence: resolving maintenance-mode feedback in action We have recently discovered a new class of quiescent, relatively common early-type galaxy that hosts large-scale, AGN-driven winds (Cheung et al., 2016, Roy et al, 2018). This discovery is exciting because these red geysers- found in ~10% of the quiescent population- may be the missing energy source needed to maintain galaxies quiescent at late times. As initially revealed in integral field observations from the MaNGA survey (Bundy et al., 2015), red geysers feature characteristic ionized gas velocity fields that are roughly co-aligned with bisymmetric features of enhanced line emission that we believe trace the wind axis. The mass of gas is the ionized phase is small, but most of the mass is expected to be in the cold gas component. We propose to map two prototypical red geysers in CO(1-0) to obtain information about the amount of molecular gas associated with the outflow, its kinematics and mass outflow rate. These observations would therefore represent one of the most direct tests of the effect of maintenance-mode AGN feedback on its galaxy host. Outflows, jets, feedback Active galaxies 2021-04-30T12:44:56.000
353 2023.1.01342.S 0 Investigating the cause of Low-Frequency Turnovers in the SEDs of SFGs: Constraining the Thermal Emission The physical mechanisms which govern the radio emission and infrafred-radio correlation (IRRC) in star-forming galaxies (SFGs) are well known but poorly understood. Radio emission from SFGs is often modelled using simple two-component power laws including thermal free-free emission and non-thermal synchrotron emission. However, recent low-frequency observations from the MWA GLEAM survey have found some SFGs exhibit much more complexity in their spectral energy distributions (SEDs) including low-frequency turnovers and higher frequency kinks. These SED features are suggested to be primarily caused by free-free absorption in compact star-forming regions. A study of nearby SFGs including resolved analysis of their radio emission is therefore vital to being able to connect the physical mechanisms occuring within these galaxies to their SED features. With this understanding we will then be able to interpret the future data obtained by the SKA. We propose ALMA Band-1 and 3 observations to measure the thermal emission of a sample of 16 SFGs which includes low-frequency turnover galaxies and control galaxies to investigate the physical properties which cause differences in their SEDs. Starbursts, star formation Active galaxies 2024-10-25T01:46:19.000
354 2019.1.00964.S 163 Towards improved constraints on dark matter with strongly lensed quasars Gravitationally lensed quasars have been established as a method to detect and quantify low-mass dark matter haloes at cosmological distances. The population of low-mass haloes is dependent on the mass of the dark matter particle, thus investigations of these lenses can give independent constraints on warm dark matter. We have an ongoing a programme to make competitive inferences on the halo mass function with short observations of lensed quasars with ALMA. Here, we ask for 'snapshot' observations to identify new lens systems suitable for high-resolution follow-up in our programme. We estimate that we will detect at least 12 of these systems based on a previous large survey. If most of these sample are suitable targets, we estimate that we can put a constaint on the thermal relic mass of warm dark matter that is significantly more stringent than the current limits from lensing and other inferences after high-resolution follow-up. As we require only snapshot observations of these targets at any angular resolutions >0.5 arcsec in band 6, our programme is suitable for filler time scheduling. High-z Active Galactic Nuclei (AGN), Gravitational lenses Active galaxies 2021-02-12T10:22:07.000
355 2019.1.00492.S 1 Weighing massive protostars with salts Stars' masses decide their fates. The masses of forming high-mass stars are challenging to measure. The most direct and accurate method to measure a protostar's mass is by measuring the rotation curve of its orbiting disk. However, most high-mass stars are surrounded by a dust and molecule-rich medium that obscures the disk's kinematics. We recently discovered that several molecules, NaCl and KCl, uniquely trace the disk around high-mass protostars and are not present in the obscuring gas cores. We propose to observe a sample of high-mass protostars in these lines to kinematically measure their masses and demonstrate the viability of these lines as kinematic mass tracers. High-mass star formation ISM and star formation 2022-12-04T18:25:24.000
356 2021.1.00378.S 627 Size distributions and multi-frequency characterization of 100 disks in Ophiuchus This proposal is designed to make significant progress in two important areas in disk demographics: continuum disk sizes and multi-frequency characterization. Disk sizes set the basic architectures of planetary systems. However, even after many years of ALMA operations, the size distribution of protoplanetary disks in nearby star-forming regions still remains to be established. Similarly, while unresolved observations at single frequencies allow for interesting studies of disk mass as a function of stellar mass, cluster age, multiplicity, and SED Class, such studies require strong assumptions regarding optical depths, dust temperatures, and grain size distributions. Testing these assumptions and their dependence on disk properties requires the analysis of multi-frequency data. Here we propose a very efficient Band-4 and Band-8 program that, thanks to the use of archival data, will result in an unprecedented data set to enable demographic studies: 40 bright disks resolved at 0.2 resolution in 4 bands (Band-4, 6, 7, and 8), Band-8 disk sizes and Integrated spectral indices (between Band-4, 6, and 8) for 60 additional objects, and Band-8 continuum disk sizes for 100 objects. Disks around low-mass stars Disks and planet formation 2023-08-16T14:47:46.000
357 2015.1.00007.S 37 Not alone?: Solving the complex mass loss puzzle of U Ant We propose to observe the circumstellar environment of the carbon AGB U Ant in the CO(1-0) and CO(2-1) transitions. We will constrain the recent mass-loss history, the connection between thermal pulses and the large detached shell of dust and gas, and the nature of small scale structure within the detached shell. The interpretation of observations of detached-shell sources are often limited by low angular resolution or the lack of velocity information. The observations proposed here will have a spectral resolution of 0.6 km/s and an angular resolution of 1.5". They will spatially resolve the detached shell and the morphology of the mass loss. The spectral resolution will allow us to determine the dynamical structure of the gas. Using 3-D radiative transfer models, we will constrain the mass and temperature of the gas. Combined with hydrodynamical models we will be able to determine the mass-loss history of the star, constrain the interaction between the dust and the gas, and the influence of a suspected binary companion on the wind. The observations will in detail describe the process that is responsible for the chemical evolution of the star and the ISM. Asymptotic Giant Branch (AGB) stars Stars and stellar evolution 2020-08-06T00:00:00.000
358 2019.1.01118.S 54 The Molecular Exosphere of Ceres: Pinpointing Its Surface Origins Observations of water ice and hazes on Ceres by Dawn Space Mission point to the existence of an exosphere. Based on existing ALMA data, we establish the presence of Ceres exosphere. To reveal the true nature of the molecular exosphere, we propose high resolution observations to resolve Ceres disk spatially so to locate the surface origins of Ceres exosphere. Our ultimate goal is to: 1) pinpoint exact locations of solar sputtering and/or outgassing plumes; 2) associate the exospheric molecular species with surface features hence compositions to better understand ice chemistry; 3) distinguish molecular excitation mechanisms; 4) identify potentially plume-launching subsurface sites of reservoirs enriched in water ice; and 5) ascertain the viability of Ceres cometary origin via accretion or formation at great heliocentric distance. Solar system - Planetary atmospheres Solar system 2022-08-18T22:51:13.000
359 2019.2.00135.S 88 The effect of the massive stellar feedback across the Carina Nebula Complex We have successfully completed an ALMA campaign in Cycle 4, 5 and 6 to study the location, mass distribution, and kinematics of the small-scale fragments within massive star-forming clumps in two regions with very different physical conditions, the Southern Pillars (SP) and the Northern Cloud (NC). We propose to expand this successfully observational campaign towards 10 regions in the Carina Nebula Complex using the ACA 7m in Band 3. This represents, to our best knowledge, the first survey of clumps at high resolution conducted in this extreme region of massive star formation. Detailed comparison of the distribution of the dense gas and the location of young stellar objects will shed light on the dependence of the star-formation threshold on the level of turbulence and external pressure in these clouds with different level of impact of stellar feedback. Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2022-11-18T16:50:56.000
360 2022.1.01058.S 0 Reveal the 10~au scale substructures in two protostellar disks Small-scale substructures, including spiral arms and misaligned/warped inner disk, have been found in circumstellar disks around low-mass protostars when they are still in a disk forming phase (Class 0/I). To study these substructures is important for our understanding of star/planet formation and origin of multiplicity. Within the intermediate mass star forming region NGC2071IR, we have identified two sources (IRS1, IRS3) with strong evidence of disk substructures at a few 10AU scale. IRS1 is an intermediate mass protostellar system (3Msun Intermediate-mass star formation, Low-mass star formation ISM and star formation 2024-09-08T12:27:28.000
361 2018.1.01536.S 16 Measuring magnetic fields of galaxies in the early Universe Although the magnetic field of galaxies are expected to be generated already early in their existence, very few observations of magnetic fields at high redshifts exist. It has been suggested the polarisation observations of the CII fine structure line can provide a unique probe of ISM magnetic fields, both in our Galaxy and far beyond. Observing CII polarisation has so far been impossible because of the lack of instrumentation. However, in high-z sources, ALMA has shown it has the sensitivity to detect CII at high signal to noise. This opens up the possibility to directly observe high-z magnetic fields. Here we propose a proof of concept by studying CII in both a quasar host galaxy and a starburst galaxy in order to probe two different regimes in which CII polarisation can be generated. Should the observations, requiring only 6 hours of ALMA time, be successful, it will not only prove the use of fine structure lines in ISM magnetic field studies, but also open up a window to study magnetic fields all the way into the epoch of reionisation. Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) Galaxy evolution 2020-08-06T01:32:05.000
362 2016.1.01043.S 40 Determining the Physical State of Two Massive, Dynamically Ambiguous Galaxy Clusters Galaxy clusters are vital probes of cosmology. Much progress has been made with the simple assumptions that they are relaxed and spherically symmetric, but high angular resolution X-ray observations from Chandra and XMM over the past decade and a half have revealed that clusters show a variety of deviations from this simple concept of equilibrium. More recently high angular resolution SZE observations have emerged as a powerful and complementary technique. In several cases high-resolution (~10") SZE observations have identified very hot, 100-kpc scale regions of very well studied clusters which had previously been missed by modern X-ray observations. It is important to observationally quantify the prevalance and character of these disturbances to have a complete & accurate picture of galaxy clusters. MUSTANG SZ observations of Abell 611 and MACSJ1206-0847 showed low- to medium-significance hints of 100-kpc scale hot gas. These clusters also showed a mix of other dynamical markers. We propose here to conclusively unveil & characterize these features with 5" - 10" resolution, targeted SZE imaging using ALMA Band 3. Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters Cosmology 2018-02-21T16:57:13.000
363 2018.1.01660.S 17 Imaging possible self-gravitation effects in the disk around a high-mass protostar Self-gravitation effects and disk fragmentation are expected to play a fundamental role in high-mass formation, both to enable high accretion rates and to produce the massive companions that are observed around high-mass stars. IRAS13481-6124 is a 20 solar mass high-mass protostar, whose inner disk structure has been studied extensively with our near- and mid-infrared interferometric observations. Our radiative transfer modeling and ATCA millimeter interferometry suggests that the disk mass is comparable to the mass of the central object. Intriguingly, in ALMA Cycle 5 observations we detected an spiral arm feature in the inner 300 AU around the object, whose morphology is similar to the ones seens in hydrodynamic simulations of self-gravitation disks. Here, we propose follow-up observations with 2.5-times high resolution and in a complementary frequency band that will allow us to characterise the physical conditions in the spiral arm and to resolve possible sub-structure, informing hydrodynamic simulations that will be conducted by the theory experts in our team. Disks around high-mass stars Disks and planet formation 2020-10-29T15:39:56.000
364 2022.A.00017.S 15 Support for JWST Observations of the Closest Solar Type Star alpha Centauri We propose a single, 2 hr observation of alpha Centauri to improve the absolute astrometry of the star in support of an approved and scheduled program with the James Webb Space Telescope (JWST) to search for a planet orbiting our nearest solar type neighbor. Main sequence stars Stars and stellar evolution 2023-12-08T21:33:04.000
365 2013.1.00978.S 1 The Orcus-Vanth System: A Rosetta Stone for accretion in planetary systems The dwarf planets in the Kuiper belt provide one of the most compelling cases of the breakdown of the simple theory of pairwise accretion. The formation of these large rock-rich dwa rf planets through coagulation of the population of small low density near rock-free objects appears difficult. Alternative accretion theories predict a wide variety of behaviors of the size-density relationship through the small body-large body transition. The Orcus-Vanth binary system is uniquely suited to determining the density behavior through this transition and pointing to the accretion hi story of the solar system. The new higher resolution capabilities of ALMA in Cycle 2 allow us, for the first time, to use resolved thermal radiometry to measure the individual component sizes and, the unique capability of highly accurate relative astrometry over moderate angles will let us determine the astrometric wobble of Orcus induced by Vanth to measure the individual component masses, yield ing simultaneous densities of two of these transitional objects and a chance to determine how solid bodies in planetary systems form. Solar system - Trans-Neptunian Objects (TNOs) Solar system 2016-09-29T14:55:19.000
366 2016.1.00540.S 49 Unveiling the jet core and central stellar object of the "water fountain" source W43A "Water fountain" sources exhibit collimated, fast bipolar jets from AGB/post-AGB stars traced by water masers. Here we propose imaging of molecular (thermal and maser) lines (including shock traces) and continuum emission toward the archetypical water fountain W43A. VLBI observations of H2O, SiO, and OH masers in W43A at milliarcsecond resolution have found bow-shock and point-symmetric clumpy structures in the jet, a biconical fast flow in the vicinity of the star, and a spherical and slow expansion of the circumstellar envelope. Together with these components, the decadal evolution of the H2O maser distribution and the bipolar morphology of the mid-infrared emission suggest that W43A has just entered the water fountain stage. Before the records of the jet and envelope evolution are lost by the photoionization by the central stellar object to form a planetary nebula, we wish to reveal the whole kinematic and physical structure of W43A in order to unvail the central stellar system. W43A is the most promising source for exploring the central system, i.e., a rotating torus or a binary system in the vicinity (~40 AU) of the central system through sub-mm SiO maser emission. Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure Stars and stellar evolution 2018-10-18T01:13:16.000
367 2012.1.00090.S 0 The bright end of the submm galaxy counts: real or not? v1 Recent submm interferometric studies with ALMA and SMA of bright submm sources from single-dish bolometer surveys have hinted that most of the brightest sources (850um fluxes > 10mJy) actually represent blends of several, fainter, SMGs. This would have significant implications for the number density of the most luminous SMGs, Hyper-Luminous IR Galaxies (HyLIRGs), and the use of the number counts of these bright sources to constrain theoretical galaxy formation models (which in some cases have required significant alterations to fit the potentially erroneous counts). However, the current ALMA/SMA studies comprise just ~10 submm sources and so we propose short ALMA Band 7 continuum snapshots of 30 >10mJy sources from a new SCUBA-2 survey of the equatorial SXDF-UKIDSS/UDS field. These observations of a statistically significant sample will allow us to determine the average multiplicity of bright submm sources, derive the true form of the bright source counts (necessary to constrain models) and produce uncontaminated samples of real HyLIRG SMGs for study. Starburst galaxies, Sub-mm Galaxies (SMG) Active galaxies 2014-11-07T09:35:00.000
368 2021.1.01015.S 7 Characterization of highly excited gas in the most distant submillimeter galaxy We propose to conduct 0.4arcsec-resolution observations of the CO(12-11) and CO(11-10) emission lines in SPT0311-58 at z=6.900, which is the highest redshift SMG. These two lines can be simultaneously observed with a single frequency setup, doubling the efficiency of observations. The CO(6-5), CO(7-6), and CO(10-9) emission lines are detected in previous ALMA observations. Combining the proposed observations with the previous ones, we will investigate the CO spectral line energy distributions (SLED) of highly excited gas in the central 1 kpc region of the SMG at z=7. If we find the CO SLED is similar to that of the nearest quasar, Mrk231, it would be a signature of dust-obscured quasars at z=7, which have not been discovered yet. In obscured quasars, black holes grow faster than an unobscured phase. Therefore, the detailed study of the CO SLED in a SMG at z=7 would provide new insights into our understanding of the early growth of supermassive black holes. Sub-mm Galaxies (SMG) Galaxy evolution 2023-12-29T14:16:07.000
369 2017.1.00326.S 548 ALMA Follow-up Survey for Clumpy Galaxies at z~0.9 in the COSMOS Field We recently performed a systematic survey for clumpy galaxies in the COSMOS 2 deg^2 field and found that the fraction of clumpy galaxies strongly depends on specific star formation rate (star formation rate per unit stellar mass) but not on stellar mass. This discovery is consistent with the gravitational fragmentation scenario of the formation of clumpy disks. In order to confirm this scenario, we here propose submillimeter continuum observations of a sample of 30 clumpy galaxies as well as a control sample of 30 normal (non-clumpy) disk galaxies at 0.7 < z < 1.0 at Band 7 on ALMA. Our immediate objectives are 1) to estimate gas-to-stellar mass ratio of our target galaxies, and 2) to directly compare these properties between clumpy and normal disk galaxies at the same redshift range. The proposed observation provides us a unique opportunity to understand the origin of their clumpy morphology and the transition to normal disk galaxies. Starbursts, star formation Active galaxies 2019-04-30T21:46:18.000
370 2011.0.00471.S 0 30 Doradus: Dense Gas in the Nearest Super-Star Cluster v0.13.1 30 Doradus is the nearest super-star cluster, and an ideal laboratory in which to study the effects of vigorous star formation on molecular gas in galaxies. We propose to image the northern molecular cloud in 30 Doradus, showcasing the unprecedented power of ALMA, even in early science, to understand detailed physical conditions in extragalactic multiphase interstellar media. We will image the entire cloud in the most commonly used extragalactic dense gas tracers including HCN 1-0, HCO+ 1-0, and CS 2-1 (and isotopologues), measure the density, mass and gravitational support of dense starless and starforming cores. We will image most of the cloud in 12 and 13CO 2-1 and other tracers of the warm interclump medium of this starburst photodissociation region (PDR), resolving the PDR structure. In combination with our Spitzer and Herschel data, and radio recombination line images obtained simultaneously with the molecular emission, we will model the physical conditions and amount of "dark molecular hydrogen" in a real starburst PDR at reduced metallicity for the first time. Finally, we will image a small region in high-excitation lines including CO 6-5 that are particularly sensitive to conditions in the hot dense clumps of PDRs. Detailed analysis of the molecular environment of the nearest reduced-metallicity starburst will inform the interpretation of many ALMA observations, revealing the true nature of the gas emitting brightly in these lines in more distant galaxies Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR), Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2013-03-13T17:57:00.000
371 2013.1.00668.S 13 Probing the Gas Excitation in high redshift Main Sequence Galaxies Recent CO observations in normal main-sequence galaxies at high redshift have shown that their star formation efficiency is lower than in case of merger driven SMGs, more consistent with the star formation efficiency in local spiral galaxies. The picture that emerges from this studies is that SMGs form stars more rapidly because their gas clouds are more compressed so they churn more quickly through the available gas reservoir than the typical normal high-z disk galaxies. These differences in the physical conditions of the ISM are expected to affect the CO and CI line ratios. Indeed earlier studies of low-J CO transitions suggest that main sequence galaxies have similar ISM properties than the MW. A coherent picture of the gas excitation in these systems, however, is missing so far. We here aim to investigate the gas excitation in three main-sequence galaxies selected from the PHIBSS survey. We propose to study the shape of the CO SED in conjunction with both lines of atomic carbon to investigate the physical conditions of their ISM. Our study aims to provide for the first time well characterized templates of the gas excitation in high redshift main-sequence galaxies. Starburst galaxies, Galaxy structure & evolution Active galaxies 2015-10-16T13:24:05.000
372 2013.1.01035.S 16 Dissecting filaments with ALMA: Unveiling the dynamic properties of dense cores within a massive IRDC Our aim is to measure the non-thermal contribution to the velocity dispersion, as well to gain an understanding of the internal motions of massive starless cores with respect to their envelope. To do this, we have selected a massive filamentary IRDC thought to be in an early stage of its evolution. We focus on several cores within a specified region, chosen as it is at the intersection point of several dense filamentary structures. We request 7 pointings in total towards this region at 1.3'' resolution (0.02 pc, or 4000 AU). Our primary tracer will be N2H+ (3-2), which is perfectly suited to tracing dense cores in regions such as this. We have selected several other molecular lines to strike a balance between cold, dense gas and warm, shocked gas. This is to reflect the pre- and proto-stellar core population. This project will enable us, for the first time, to link to dynamic properties of cores to that of their natal filamentary envelopes, gaining an understanding of their formation and growth. Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2016-05-12T17:37:35.000
373 2017.1.00822.S 15 Surveying the ISM in gas-rich galaxies at z=3-5 through the HFF cluster MACS 1149+2223 The Hubble Frontier Fields (HFF) program has provided six well-calibrated gravitational lensing clusters which can be exploited to provide uniquely sensitive views of the formation and evolution of high-redshift galaxy populations. We have used one of the most massive HFF lenses, MACSJ1149+2223, along with JVLA to study the radio continuum and cool gas, CO(1-0), content of a sample of high-redshift galaxies at z~3-5 with unprecedented sensitivity. In this proposal we aim to complement these surveys with ALMA observations whose goal is to characterise the ISM in these young, forming galaxies. We propose deep, Band 3 observations through the heart of the cluster to search for CO(4-3) and [CI](1-0) line emission at z=3-5. In six pointings, we will map the entire critical curve, where magnification factors are as high as 100. Along with our existing JVLA CO(1-0) data, covering the same area and redshift range, these ALMA observations of lensed sources will provide unparalleled diagnostic power over the molecular gas masses and excitations in normal star-forming galaxies at high redshift. Sub-mm Galaxies (SMG), Gravitational lenses Galaxy evolution 2020-01-08T12:15:36.000
374 2016.1.01262.S 132 Caught in the act: ALMA witnesses galaxy transformation Understanding why star formation is shut down galaxies is important for understanding their origins, the quenching mechanism, and how rapidly galaxies build up the red-sequence. The stacked far-infrared fluxes of the first robust sample of z~1 post-starburst galaxies reveal a surprising result - that quenching galaxies still have substaintial dust contents. This finding is at odds with the expectation that these galaxies have run out of gas and will enter the red-sequence in the next few 100 Myr. Using 18 hours of ALMA time we propose a study of the dust and gas properties of 9 massive, ultra-compact z~1 galaxies which are undergoing rapid quenching of their star formation. Our observations will allow us to determine whether these galaxies are devoid of gas. If we find significant gas contents, then these galaxies may rejuvenate, which will require us to revise the popular scenario in which red-sequence galaxies are formed after a single quenching episode. ALMA observations of z~1 galaxies caught in the act of transforming will help confirm or refute the rapid quenching mode of forming red sequence galaxies. Starbursts, star formation, Merging and interacting galaxies Active galaxies 2018-03-21T20:17:48.000
375 2019.1.01347.S 2 Probing the thermal properties of the chromosphere at high resolution We propose to improve our knowledge of the thermal structuring of the solar chromosphere by obtaining the highest-resolution ALMA observations in Band 3 (100 GHz). This will build on our earlier results by measuring the key spatial scales of the temperature variations in the upper chromosphere. Our previous analysis showed that the interpretation of the millimeter-wavelength brightness temperature needed to consider radiative transfer effects to properly understand the temperature stratification along the line of sight. The higher-resolution ALMA observations, combined with other spectral diagnostics in the optical and UV, will allow us to determine how closely coupled different regions of the solar chromosphere might be. It will also allow a more robust study of the small-scale dynamics of the chromosphere. The Sun Sun 2022-10-21T14:31:14.000
376 2013.1.00783.S 6 ALMA Identification of An Accreting Disk in a Proto-Brown Dwarf Candidate, L328-IRS, and Its Implication L328-IRS as a Very Low Luminosity Object (VeLLO) is believed to be a proto-brown dwarf forming like a normal star and it may be one of the best example for studying the origin of the brown dwarf. Because a CO outflow from this source is discovered, its accreting disk is expected to exist as a main path for the accretion flow onto the proto-brown dwarf and also a launching ground of the outflow. We propose to make the first search for a disk structure in a proto-brown dwarf in C18O and 13CO 2-1 with ALMA. Finding a possible Keplerian disk and precise measurement of the dust envelope around L328-IRS from 1.2mm continuum observation will enable to discuss whether L328-IRS is a bona fide proto-brown dwarf and how the disk of a proto-brown dwarf is similarly forming compared with those of ordinary protostars. Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2016-03-18T13:32:33.000
377 2021.2.00118.S 10 A misaligned, asymmetric dust ring in a circumtriple disk We will carry out Band 4 ACA observations in the dust continuum of the circumtriple disk around GW Ori. The project will serve as a supplement to a partially executed Cycle 7 proposal in Band 4, which suffers from significant flux missing due to the unexecuted short-baseline observations. Moreover, combined with the archived Band 6 data and the recently delivered Band 4 data, the proposed observations will allow us to constrain the dust grain size via spectral energy distribution modeling, and investigate the origin of an asymmetry in the dust ring revealed by previous Band 6 observations. Disks around high-mass stars Disks and planet formation 2023-01-14T10:27:19.000
378 2021.1.01578.S 120 Is accretion driven by magnetic disk winds in Class 0? Recent numerical simulations propose that the accretion in disks is governed by the launching of magnetic winds that would extract angular momentum. During the earliest protostellar phase (Class 0), MHD disk winds would then regulate the formation and evolution of the disk and set the final mass of the growing star. Previous ALMA observations have brought first evidence of MHD disk winds in three Class 0 sources, observed as rotating outflows seen as at small scale (<150au). The time is ripe to determine if MHD disk winds are ubiquitous in Class 0 protostars or if they are the exception. We propose here to map at high resolution (~35 au) and high sensitivity (3K in a 0.25km/s channel) the base of five promising outflows emanating Class 0 sources in Perseus to seach for signatures of rotation. This pilot survey will constitute the first discriminant tests of the newly proposed paradigm that disk accretion is regulated by MHD disk winds. Outflows, jets and ionized winds, Low-mass star formation ISM and star formation 2022-11-30T13:10:17.000
379 2017.1.01413.S 61 Chemistry Unveils the Physics of Embedded Disks Embedded disks form during the star formation process due to angular momentum conservation of infalling gas and likely represent the initial conditions for planet formation. Although more evolved protoplanetary disks are relatively well characterized, the physical conditions of their precursor embedded disks are poorly constrained. Embedded disks tend to be more massive, but density, gas temperatures and UV irradiation levels are unconstrained. We will characterize the temperatures and incident radiation fields by observing a suite of diagnostic molecular lines toward five embedded disks in Taurus (D~140 pc). To characterize the disk temperatures, we will use line ratios of H2CO J=4-3 transitions. Observations of N2H+ will determine whether or not embedded disks have a cold midplane (T<~20 K) where CO is frozen out. The radiation field incident upon the disks will be constrained with the CN/H13CN ratio as function of radius; CN is a direct product of HCN photodissociation. These diagnostic probes will enable the initial conditions for protoplanetary disk evolution (and possibly planet formation) to be characterized for the first time. Low-mass star formation, Astrochemistry ISM and star formation 2019-11-15T13:55:00.000
380 2018.1.00147.S 22 Deep Search for Galaxy Overdensities around the Highest-redshift Quasars We propose deep ALMA Band 6 observations around the two highest-redshift quasars at z=7.54 and z=7.09 over 3'x3' corresponding to 1x1 physical Mpc2 at their redshifts down to a depth of 0.3 mJy (1.3 mm, 5 sigma). Our panoramic deep observations will enable us to examine the presence of galaxy overdensities around the luminous quasars based on their obscured view, which has been missed in previous work. We will address the following three science goals: 1) Deriving the number counts of dusty star-forming galaxies in these quasar fields, 2) Characterizing dust emission properties of UV-selected galaxy candidates at around the quasar redshifts, and 3) Unveiling the 3D structure of [CII]-emitting sources around these quasars. The combination of our proposed ALMA data, previously obtained archival data such as HST and Spitzer, and forthcoming JWST data for these highest redshift quasar fields will unveil the distributions of both obscured and unobscured star formation in possibly biased regions at high redshifts, which will be helpful to understand an early phase of galaxy evolution. Sub-mm Galaxies (SMG), Galaxy Clusters Galaxy evolution 2022-10-26T13:17:30.000
381 2021.A.00020.S 40 Confirmation of a z = 12.3 galaxy candidate We ask for 16 hours of ALMA band 6 time to acquire the spectroscopic redshift of a robust bright galaxy candidate at z=12.3 identified in the Early Release Science Programs of the JWST. If confirmed, this galaxy would be the highest-redshift galaxy known to date and will provide strong constraints on the UV luminosity function and on galaxy formation models. We combine four spectral tunings to form a contiguous frequency coverage across redshifts 11.9 to 13.5 (covering more than 90% of the redshift probability distribution of the source), targeting the doubly-ionized Oxygen [OIII] emission. Meanwhile, these observations will provide strong constraints on the dust emission (down to an obscured fraction of 1) and internal ISM conditions (including metallicity) of a galaxy observed ~350Myr after the Big Bang. Through this high-reward proposal, ALMA will uniquely provide the essential and complementary perspective on one of the key goals of the JWST mission. Lyman Break Galaxies (LBG) Galaxy evolution 2022-08-09T03:58:24.000
382 2023.1.01660.S 0 NGC 4945: The Milky Way's not-so-distant Cousin - ACA Standalone Mapping of the Full Disk in Band 3 Dense Gas Tracers Star formation correlates mostly directly with dense gas, but spectroscopic tracers of dense gas are incredibly faint with low surface brightness. As a result, we still know relatively little about the resolved structure of dense gas in galaxy disks and its relation to other parts of the galaxy. To address, we propose ACA standalone mapping of the full disk of the nearest starburst+disk galaxy NGC 4945 in Band 3 dense gas tracers (8 lines in total). Our map will cover 10kpc along the major axis of the galaxy, extending previous dense gas studies of starburst systems which focus heavily on galaxy nuclei (<1arcmin^2). This will yield continuous, uniform measurements of the dense gas abundance and efficiency spanning from the starburst nucleus across the disk environments, adressing major open questions. The inclined geometry and proximity of the target and the need for surface brightness sensitivity make this a highly productive, novel use of the ACA. Starbursts, star formation, Spiral galaxies Active galaxies 2025-04-29T18:46:40.000
383 2016.1.00983.S 91 Mass Loss from OH/IR Stars in the Inner Galactic Bulge We propose to use ALMA to detect the 12CO J=2-1, 12CO J=3-2, and 13CO J=3-2 lines from the envelopes of 22 OH/IR stars in the inner Galactic bulge. This is impossible with a single-dish instrument due to the extended emission from interstellar molecular clouds. We will use the data to determine these stars' mass-loss rates to help measure the inner Bulge's ISM replenishment. Asymptotic Giant Branch (AGB) stars Stars and stellar evolution 2017-11-16T11:15:48.000
384 2013.1.00157.S 21 Revealing Binarity and the Youngest Disks in Oph We propose a survey of multiplicity toward all known Class 0 and Class I protostars in Oph (50 sources). Using a dust continuum sensitivity of 0.1 Jupiter masses, we will probe the binarity of these sources from 15 AU out to 1000 AU, which well samples the peak of the main-sequence and pre-main sequence binary separation distributions (30 and 60 AU) toward the younger protostars for the first time. Combining with our Perseus VLA 8mm continuum survey, we will have 130 sources (great statistics) in two clouds, which will mitigate concerns of environment. This is the largest and most complete high-resolution millimeter-wave survey of protostellar binaries ever undertaken and will significantly improve our understanding of the formation mechanisms and prevalence of close binaries during the early stages of star formation. In addition, the survey will also be perfect for detecting protostellar circumstellar disks. There are currently only 2 disks in Class 0 sources known, so this project will increase the number of candidate Class 0 and I disks, help resolve the current controversy on early disk properties, and constrain disk formation scenarios that are hotly debated. Low-mass star formation ISM and star formation 2016-09-23T14:38:25.000
385 2022.1.01438.S 35 Revealing the 12C/13C ratio across the galactocentric radius through sensitive absorption detection It has long been proposed that the 12C/13C isotopic ratio can be used as a diagnostic for the evolutionary stage of stars and galaxies. The current Galactic 12C/13C gradient by Milam et al. (2005) has been frequently used in various astrochemistry works. However, their work does not consider the contribution from CMB temperature, and the Rayleigh-Jeans approximation used in their analysis is not suitable for millimeter wavelengths. Correcting for all of these effects, we found that the values of 12C/13C ratio are up to 50% smaller than the previous ones. We propose here to measure the 12C/13C ratio through sensitive absorption observations toward five quasars. Each of the sightline has more than three velocity components, which trace gas components at different spiral arms. With the proposed sensitivity, we will be able to measure the HCO+/H13CO+ ratio at different galactocentric radii. Our aims are: 1) to reveal the Galactic 12C/13C gradient through this independent measurements, 2) to measure the fractionation effect on the 12C/13C ratio in diffuse clouds, and 3) to measure the photodissociation effect on the 12C/13C ratio. Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2024-04-12T09:38:59.000
386 2018.1.00870.S 181 A multiphase investigation of AGN feedback The broad scientific objective of this project is to advance in our understanding of AGN feedback and its connection with the galaxies molecular gas reservoirs. We propose to perform the first multiphase characterization of outflow properties (size, geometry, kinematics and mass) in a sample of nearby and luminous type-2 quasars (QSO2s). By combining the requested ALMA observations with available VLT/SINFONI data we will study the properties of the line-emitting gas in the ionized, hot and cold molecular phases for a pilot sample of 7 QSO2s. These AGN are drawn from a larger sample and are representative of the luminous QSO2 population in terms of bolometric and radio luminosity, morphology and SFR. We will also investigate for quasar circum-nuclear disks (CNDs) of molecular gas, characterize them and study their connection with the host galaxy via outflows. We ultimately wish to answer the important questions of whether quasars with luminous outflows differ in terms of the molecular gas reservoirs from those without outflows and/or whether there is a dependency with the outflow properties. Outflows, jets, feedback Active galaxies 2020-08-28T23:12:19.000
387 2016.1.00231.S 123 Imaging the most distant and extreme starbursts in the Universe In Cycle 3 we performed a redshift search (via scans of the 3mm band) of 27 sources where 7 of these were selected to be red based on the ratio of their 870um/500um flux ratio. This program was a great success with 55% of the sources above z>4 and with the detection of a z=6.9 source. As a part of this program we proposed to do high resolution imaging (via high-spatial-resolution 870micron continuum imaging) of these sources to determine their lens magnification. Since this data has not yet been observed and our proposal was assigned to the B category in cycle 3 we here resubmit this essential part of the program, adding eight sources to complete our sample of sources with redshifts. In 6.2 hours we will image 35 sources almost doubling our published sample (Spilker et al. 2016). Only when knowing the magnification can we determine the intrinsic properties of the sources. At redshifts approaching z=7 we are closing in on the era just a few Myr after Big Bang, and it is of profound and urgent interest to characterize the intrinsic properties of these sources since these seem to challenge the accepted models of galaxy and structure formation. Starburst galaxies, Sub-mm Galaxies (SMG) Active galaxies 2018-07-27T19:37:17.000
388 2021.1.01378.S 24 Probing the molecular outflows and dusty nuclei in local U/LIRGs Molecular outflow is commonly seen in local (ultra)luminous infrared galaxies (U/LIRGs). These outflows are considered to be important in regulating star formation and the growth of galaxy nuclei. Recent observational efforts have revealed that the molecular outflows are chemically differentiated due to the shock and/or high temperature chemistry. Up to now, the elevated HCN emission has been found in a number of outflows. In such outflows, CN and CCH could also be abundant, because these species can be rapidly formed in the gas phase where C+ and H2 are abundant, even before HCN increase. We hereby propose to observe the CN (N=2-1) and CCH (N=2-1) lines toward three U/LIRGs with different properties, IRAS 17208-0014, IRAS F05189-2524, and ESO 320-G030. In conjunction with previously observed HCN, HCO+, and CO, we will characterize the chemical conditions of the outflows. Specifically, we will investigate if the distribution of CN and CCH is different from other molecular species in the position-velocity space. This will give us an insight into the evolution of gas properties in the outflow. Outflows, jets, feedback, Galaxy chemistry Active galaxies 2023-08-23T22:20:18.000
389 2018.1.00917.S 319 Monitoring the Sub-mm Brightness in the Inner Envelopes of Known Variable Deeply Embedded Protostars We propose to use the standalone mode of the ACA to obtain band 7 continuum observations for 4 epochs over cycle 6 of three known variable protostars and 5 stable calibrator sources in the Serpens Main Cloud. The observations will take place contemporaneously with the JCMT Transient Survey, which observes the region at a two to four week cadence. The ACA observations will monitor the brightness evolution in the inner envelope where the dust responds only to changes in the source accretion luminosity. At the distance to Serpens Main of ~415pc, our ACA observations will resolve scales of ~3.8"/1580 AU and recover scales as large as ~19.7"/8175 AU, complementing the JCMT's angular resolution at 850 microns of ~14.6"/6060AU. Thus, comparison between the JCMT and ACA observations will provide critical information on the structure of the envelope, its variability, and its environment. Furthermore, any stochastic event that might occur during the cycle will manifest itself in the ACA observations weeks to months earlier than in the JCMT observations, providing an unambiguous probe of the dust response rate through the envelope. Low-mass star formation ISM and star formation 2021-01-11T03:35:28.000
390 2017.1.00396.S 116 A bright QSO at z~7.5: pushing detailed interstellar medium studies to the earliest cosmic epochs After almost a decade of intense search, we have finally discovered a bright QSO well within the reionization epoch at z=7.5424. With NOEMA we detected the dust continuum and a bright, 300 km/s wide [CII] line in this source. The presence of a supermassive black hole, dust, and intense star formation at this redshift imposes new challenges on structure and galaxy formation. The combination of the bright [CII] emission and the redshift of this source enables an unprecedented ALMA study of 18 molecular and fine-structure lines with rest-wavelengths as short as 88um ([OIII]). Here we propose (i) high resolution (0.2", ~1 kpc) imaging of the [CII] line to constrain the morphology/kinematics of the gas to measure the dynamical mass of the QSO host, map its star formation activity, and identify signs of mergers; and (ii) target a suite of molecular and fine-structure lines that combined will reveal key physical conditions such as density, temperature, metallicity, ionization degree, and hardness of the radiation field. This remarkable QSO provides a unique laboratory for ALMA to push detailed studies of star formation and the interstellar medium to the highest accessible redshift. Starburst galaxies, High-z Active Galactic Nuclei (AGN) Active galaxies 2019-06-21T18:14:49.000
391 2021.1.01210.T 159 A Systematic Survey of Jets and Outflows in Tidal Disruption Events with ALMA Transient accretion onto a supermassive black hole (SMBH) through the tidal disruption of a stray star offers a unique opportunity to study the birth and evolution of relativistic jets and to probe the environment around previously dormant SMBHs on sub-parsec scales. The past few years have shown that some tidal disruption events (TDEs) launch relativistic jets and broad outflows that generate synchrotron emission peaking in the mm on timescales of days to weeks. The faintest TDE outflows seen to date are ~10^4 times less luminous than the brightest known TDE jet and remain mysterious. To understand this diversity and determine the origin of the faintest outflows requires: (i) a larger sample of TDEs from a diverse range of selection methods, and (ii) deep mm follow-up, only possible with ALMA. Here, we propose to observe up to 8 new TDE candidates with triggers from gamma-ray, X-ray, or optical surveys (e.g. Swift, Fermi, XMM-Newton Slew Survey, eROSITA, ASAS-SN, Gaia, DES, YSE, ZTF). Our mm observations will be sensitive to both non-relativistic outflows and relativistic jets and will constrain jet formation models and rate predictions, which are currently highly uncertain. Outflows, jets, feedback, Galactic centres/nuclei Active galaxies 2023-12-23T14:38:04.000
392 2023.1.01052.S 0 Molecular gas distribution and dynamics in main-sequence galaxies at the peak epoch of the cosmic star formation Sensitive measurements of the CO emission line in high-z galaxies at sub-galactic scales are now possible with ALMA. In this pilot project, we propose to build a comprehensive sample of z~2 star-forming main-sequence galaxies observed in CO(3-2) emission. Making use of the ALMA archive and literature, we have gathered bright unresolved CO(3-2) detections for 4 galaxies to perform follow-up observations and resolve the galactic disks at ~2.5 kpc-scale. We will characterize the gas distribution and kinematics of the likely dominant component in term of mass in those main-sequence galaxies. We will measure the molecular gas extension, rotation velocity, velocity dispersion. The molecular gas extension will be compared with that of the stars constrained from HST-CANDELS, and future JWST, imaging. Available Halpha KMOS-IFU observations will enable reliable comparison between the molecular and ionized gas kinematics. This pilot project will provide clues about how galaxies build-up their stellar mass content at the peak of the cosmic SFRD, and pave the way for a future more ambitious ALMA project. Starbursts, star formation, Surveys of galaxies Active galaxies 3000-01-01T00:00:00.000
393 2019.1.01607.S 10 Mass-loss and the evolution of the most massive stars in the Galaxy Massive stars impact on fields as diverse as galactic evolution, core-collapse SNe and the birth of black holes and neutron stars; the latter particularly relevant with the dawn of gravitational wave astronomy. However we lack a complete understanding of their evolution: for a star of given mass we cannot yet predict how it will die, nor the nature of the resulting relativistic remnant. This is due to the lack of a theoretical framework for quantifying mass-loss, with evolutionary codes relying on empirical constraints which, at worst, are uncertain at the order of magnitude level. Consequently, we propose to observe the Arches and Quintuplet clusters, which contain very large numbers of very massive (>60 Msun) stars for which we may obtain mass-loss rates via simultaneous quantitative analysis of extant VLT spectroscopy, HST photometry and critically, ALMA mm-continuum observations. This will provide a unique insight into the dependance of mass-loss on properties such as stellar mass and luminosity for the most massive stars that Nature permits; essential input physics for stellar evolutionary as well as spectral and population synthesis codes. Hypergiants, Evolved stars - Shaping/physical structure Stars and stellar evolution 2021-06-22T15:54:05.000
394 2011.0.00232.S 0 Molecular Gas and Obscured Star-fomation in Host Galaxies of Dark Gamma-ray Bursts We will observe redshifted CO lines in two host galaxies of dark gamma-ray bursts GRB020819 (z=0.411) and GRB051022 (z=0.807) at band 6, and simultaneously obtain dust continuum emission. GRBs are considered to occur because of the deaths of massive stars, and therefore, they are closely associated with star formation in hosts. GRBs can be detected at cosmological distances and are considered to be effective indicators for star-formation activity in the distant universe. Only a small fraction of GRB hosts have been studied for which high obscured star formation is indicated, and whether GRBs occur in dust obscured star-forming regions. The two proposed GRB hosts are the best targets for CO and dust emission observations because (a) they are actively star-forming galaxies, (b) with large dust extinction (A_V > 1.5), (c) and have high metallicity environments. If we detect the CO line, this is the first detection in GRB hosts, allowing us to examine GRB hosts in terms of molecular gas for the first time. Scientific goals of this proposal are (i) to measure the amount of molecular gas and examine whether the molecular gas mass is enough to sustain the active star formation taking place in the GRB hosts, and whether GRBs occur in gas-rich parts within hosts, (ii) to reveal obscured star formation in the hosts and examine whether GRBs occur in dust obscured star-forming region, and (iii) to derive star-formation efficiency and examine whether GRB hosts are similar to those of normal star-forming galaxies or starbursts. Gamma Ray Bursts (GRB) Cosmology 2014-03-02T19:07:00.000
395 2021.1.01183.S 3 Resolving the magnetic field in the torus of NGC1068 ALMA has measured a ~10 pc-scale magnetic field in the dusty molecular torus of NGC 1068, whose structure and strength suggest to be the signature of a magneto-hydrodynamical (MHD) inflow. Subarcsecond infrared polarimetric observations have shown that the polarization from the inner edge, ~0.4 pc, of the torus is dominated by magnetically aligned dust grains in a wind. These studies suggest that the origin, evolution, and morphology of the torus can be explained as a MHD inflow/outflow model. Quantify that the B-fields are present at all scales in NGC1068's torus is required to confirm/reject the MHD outflow/inflow model. This proposal aims to obtain the pc-scale B-field in the torus of NGC 1068 using continuum linear polarization in Band 7 at an angular resolution of 0.029(1.7 pc). The measured B-field orientations will quantify whether B-fields are indeed good tracers of the gas flows towards the active nuclei or are entangled due to internal turbulence or complex dynamics in the torus. The computed B-field strength will compute the modified beta-plasma parameter to disentangle the dominant physical mechanism in the torus to put constraints in the the MHD outflow/inflow models. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2024-04-20T17:55:21.000
396 2013.1.00433.S 8 Characterizing the nature of a protogalaxy in the primordial Universe (z=7.1) seen by ALMA In our previous Cycle 1 observations we have detected [CII]158um emission in a star forming galaxy at z=7.1, well within the epoch of reionization. This is the most distant [CII] detection and in a galaxy representative of the galaxy population responsible for the reionization of the Universe. The [CII] line is extremely narrow (8 km/s) and slightly offset (a few kpc) relative to the Lya emissiion; both these features are in very nice agreement with the expectations for the distribution of ionized and cold gas from simulations of primeval galaxies. The system has a modest star formation rate (less than 10 Msun/yr), indeed in the range expected for galaxies contributing to the Universe reionization. The goals of the proposed observations are 1) to map the [CII] emission with much higher angular resolution and verify the expectatinos of models that [CII] should break up into small clumps with sizes of ~1 kpc; 2) obtain a detailed dynamical map to infer the mass distribution of the system; 3) trace the ionized component of the ISM through the [OIII]88um line, which is not affected by IGM absorption, and which is expected to have a smoother and broader distribution than [CII]. Lyman Break Galaxies (LBG) Galaxy evolution 2016-12-08T18:09:01.000
397 2022.1.01013.S 29 Tracking the Millimeter Emission from the Relativistic Tidal Disruption Event AT2022cmc Transient accretion onto a supermassive black hole through the tidal disruption of a stray star offers a unique opportunity to probe the environment around quiescent galactic nuclei and to map the lifecycle of relativistic jets and outflows. In 2011, radio and millimeter observations of the tidal disruption event (TDE) Swift J1644+57 revealed that these dramatic events can power luminous relativistic jets. Nevertheless, observations have revealed that powerful jets in TDEs are extremely rare; despite over a decade of searching, Swift J1644+57 remains the only well-studied jetted TDE to date. In this proposal we request millimeter observations of the recently discovered transient AT2022cmc, the first TDE observed to launch a powerful relativistic jet in 11 years. The observations proposed here will measure a possible jet break, track the peak of the spectral energy distribution (SED) as it evolves through the millimeter band, and determine the spectral index of the optically thin portion of the SED, uniquely determining the outflow kinetic energy, jet collimation, and the density profile around the SMBH. Outflows, jets, feedback, Galactic centres/nuclei Active galaxies 2024-07-26T01:11:49.000
398 2018.1.00744.S 348 Evolution of outflow-envelope interactions in low-mass protostars We propose ALMA observations to study the evolution of the outflow-envelope interaction using a sample of 21 low-mass protostars at different evolutionary stages in the Orion A molecular cloud. We will conduct multi-line observations of the environment around these protostars that will allow us to trace the distribution of the outflowing gas (and its momentum and energy) with respect to the kinematics and structure of the infalling envelope. We will map each source with a 7-point mosaic and the ACA to obtain data with a resolution of about 450 AU and sensitive to structures extending up to about 0.1 pc scales, ideal for studying the properties of both outflows and envelopes. Combining the proposed observations with radiative transfer models, we aim to: 1) determine the importance of outflows in the removal of dense gas around protostars and its effect on the core-to-star efficiency; 2) establish how infall and outflow rates change of over the lifetime of prototstars and understand their effect on the core mass-loss process at different evolutionary stages; and 3) use the results to develop an empirical model of the evolution of the mass-assembling process of low-mass protostars. Outflows, jets and ionized winds, Low-mass star formation ISM and star formation 2020-08-14T02:27:20.000
399 2016.2.00015.S 55 Debris Disk Structure Around Nearby Sun-like Stars with the ACA We have assembled resolved millimeter continuum observations of a sample of the eight brightest debris disks around the closest (<20 pc) Sun-like (FGK) stars using ALMA. These data will allow us to (1) quantify surface density structures and address the basic dynamical processes that govern debris disk evolution to Gyr ages, (2) place constraints on otherwise inaccessible wide-separation planets in these systems from signatures of planet-disk interaction, and (3) make the first systematic comparative study of planetesimal structures around Sun-like stars. Several targets were observed with ALMA in previous cycles with archival data available, and we received data for all of the remaining targets during Cycle 4. While the majority of sources are well-detected, three targets are missing ciritical data at short baselines. We propose ACA observations of HD 207129, HD 38858, and HD 115617 to complement existing ALMA datasets and better characterize the planetesimal distribution in these debris disks. Completion and analysis of this nearby sample will provide a benchmark for interpretation of the large population of more distant systems. Debris disks Disks and planet formation 2018-07-22T08:14:45.000
400 2015.1.01359.S 4 Investigating the feeding of a baby radio galaxy Young radio AGN are very suitable objects to study the role of molecular gas in the triggering and fuelling mechanisms of AGN. They are rich in cold gas close to the active nucleus and often show a strong interplay between the cold gas and the radio plasma, such as gas inflows and outflows. Such AGN-ISM interactions are thought to play a crucial role in galaxy evolution. We propose ALMA observations of the closest gas-rich young radio AGN PKS1718-649 (D=62 Mpc). It is a newly born radio AGN where, very close to the AGN, the atomic and the molecular hydrogen show highly disturbed kinematics, indicative of a strong on-going interaction with the radio source. Because of its proximity, we can study at high resolution (60 pc) the kinematics of the cold molecular gas (CO v=0 2-1) with ALMA. We will be able to separate the different kinematic components in the very inner regions, disentangle the complex geometry of the cold gas and identify what is contributing to fuel the radio AGN. This will provide a unique opportunity to analyze in detail the physical mechanisms of the complex interplay between a newly born radio AGN and its surrounding interstellar medium. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 2017-12-16T13:58:27.000
401 2018.1.01864.S 43 First detection of 15N2H+ - a sink for interstellar heavy nitrogen? Nitrogen isotope fractionation in prestellar cores, protostars, and protoplanetary disks is still not well understood. Because the main reservoirs, N2 and N, cannot be measured directly, our measurements rely on observations of tracer molecules. A particularly puzzling picture is thereby presented by N2H+, which shows not only a large scatter in 14N/15N ratios, but also strong depletion in a prestellar core, which current fractionation models cannot explain. One possible scenario is that 15N is hidden from our current view in the form of doubly substituted 15N2H+, similar to the high abundances of doubly deuterated molecules. Predictions for laboratory spectroscopy of 15N2H+ were recently published and allow us to search for 15N2H+ for the first time. We propose to search for 15N2H+ in the prestellar core 16293E, for which N15NH+ was already detected. These observations will prove the first measurement of a doubly 15N-substituted molecule, investigating their importance in nitrogen isotopic fractionation, and thereby advance our understanding of the origin of the nitrogen isotopic heterogeneity of the solar system. Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry ISM and star formation 2020-10-26T22:33:50.000
402 2018.1.00836.S 45 The inventory of peptide-like molecules towards low-mass protostars The molecules HNCO, CH3NCO, NH2CHO and CH3C(O)NH2 have structures that are similar to peptide bonds, [-(H)N-C(O)-], the chemical links in proteins, and thus can be precursors to biologically relevant molecules. These four molecules have been suggested to form through related reactions on interstellar dust grains. Unbiased observational constraints on their presence and abundances are limited to just one low-mass source (IRAS 16293--2422B), however. We propose to observe these molecules towards two additional low-mass protostars, NGC 1333 IRAS4A and Serpens SMM1. The aims are to: I) determine how common these molecules are around low-mass protostars, II) derive their abundances to constrain their chemistry and III) make a chemical comparison with IRAS 16293-2422B. The data will help us understand the formation pathways of these molecules, indicate whether ice or gas-phase chemistry is involved and determine how these species are chemically related to each other. Low-mass star formation, Astrochemistry ISM and star formation 2020-08-30T12:21:48.000
403 2018.1.00850.S 269 From filaments to cores: Dynamics in infrared dark clouds Massive stars shape the visible Universe, yet we do not know how they form. Currently available observations of massive star forming regions reveal a complex hierarchical structure from the global (cloud) to intermediate (filament) to individual forming star scales (cores). However, due to the lack of observations on the intermediate-to-small scales, constraining the role of these structures in the theoretical models of massive star formation is not possible. The proposed observations of a statistically meaningful sample of quiescent massive star forming clouds will allow us to: (1) separate the complex kinematics spatially and spectrally, in order to create a catalogue of coherent, filamentary structures; (2) place the properties of these structures in the context of the larger scale environment, and of the core distribution and properties identified from the proposed continuum observations; (3) Constrain the theoretical models that provide predictions regarding the role of these structures (as for e.g. mass flows) and their formation. High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2020-01-20T16:55:02.000
404 2017.1.00225.S 42 FIR [O III] and [C II] emission from a z ~ 8 candidate galaxy: A glimpse into early production of heavy elements We propose ALMA observations of a candidate z ~ 8.4 Lyman break galaxy (LBG) in the [O III] 88 micron and [C II] 158 micron lines at Band 7 and 5, respectively. In our A-graded Cycle 4 observations of this LBG, we made a 6.3-sigma detection of dust continuum emission and a marginal detection of [O III] 88 micron which suggests z_spec = 8.433. If confirmed, this will be the furthest galaxy which ALMA identifies spectroscopically. Furthermore, the proposed observations allow us (1) to characterize metal/dust enrichment for the first time when the age of the Universe was only 600 Myr and (2) to evaluate the escape fraction of ionizing photons using the [OIII]/[CII] luminosity ratio. ALMA will therefore provide a very unique opportunity before the JWST and ELT era that allows a tantalizing glimpse into the earliest production of heavy elements. Lyman Break Galaxies (LBG) Galaxy evolution 2020-09-06T09:49:20.000
405 2013.1.01223.S 12 Star formation laws and AGN activity: CO (2-1) observations of ZEUS z~1.2 [CII] sources We propose to use ALMA in Band 3 to image the CO 2-1 line from four sources at z ~ 1.2 from which we have detected the [CII] line with ZEUS/CSO. The low-J CO lines arise from PDRs and will allow us to constrain the physical conditions of the photo-dissociated regions in our sources and evaluate the possibility of an XDR contribution. In three of the four sources we will marginally spatially resolve the CO. Based on our [CII] work, we expect very large scale (~ 5 kpc radius) molecular disks in our sources. If these galaxies are forming stars in the “quiescent mode”, we expect very large molecular gas mass surface densities as well. These are required to support Schmidt-Kennicutt law star formation at the very large rates reflected in the FIR continuum and our [CII] line studies. We will also measure the underlying (rest-frame) 1.3 mm continuum emission as a proxy for the spatial distribution of the FIR continuum radiation and hence get a good handle on the spatial distribution of the surface density of star formation. We will compare this to the surface density of molecular gas (from our CO line map) to derive the star formation law within these galaxies. High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution Active galaxies 2016-10-13T20:36:48.000
406 2019.1.01600.S 756 A complete census of spectroscopic redshift of 850 micron selected high-redshift HyLIRGs Submillimeter galaxies (SMGs) that are brighter than 10 mJy at 850 micron have a total infrared luminosity greater than 10^13 solar luminosity, analogous to the neaby hyper lunimous infrared galaxies (HyLIRGs). They host sites of the most intensive star formation at high redshifts (z>1), yet due to a lack of a homogeneous sample our understanding toward this population is still limited, and models have made vastly different predictions on their properties. We have recently completed a band 7 ALMA follow-up survey of a flux-limited sample of single-dish selected submillimeter sources, detecting 50 SMGs with >10mJy flux density, representing one of the largest high-redshift HyLIRG samples. Here we propose to conduct a band 3 spectroscan on 18 SMGs with >13 mJy, aiming to 1) measure a complete redshift distribution of a flux-limited HyLIRG sample and study their ISM through CO, 2) to test the prediction of the fraction of SMGs being strongly lensed, and 3) to provide limits on the fraction of physically associated pairs on targets with closeby SMG companions. Sub-mm Galaxies (SMG) Galaxy evolution 2021-05-06T14:34:15.000
407 2013.1.00806.S 15 Needles in the Cosmic Haystack - A Hunt for Massive Starless Cores Massive star formation remains an important unsolved problem in astrophysics. Better observational constraints on its initial conditions are needed. Very few good examples of massive starless cores are known that are on the verge of star formation, i.e. scaled-up versions of highly-deuterated, centrally-concentrated low-mass pre-stellar cores. After searching four infrared dark cloud (IRDC) clumps with ALMA in Cycle 0, we detected one bona fide example in N2D+(3-2) (Tan et al. 2013). The source, C1-South, has a booming signal in this emission line. Here we propose an efficient survey of 32 more IRDC clumps to find more massive starless cores: we expect this will yield a sample of about 10 such cores, the beginnings of a statistical sample. High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2016-05-06T13:24:51.000
408 2013.1.00458.S 2 Last equatorial flows in axial PNe, effects of a binary stellar system Studying the appearance and properties of bipolar winds is critical for understanding the stellar evolution from the AGB to the planetary nebula (PN) phase. Many uncertainties exist regarding the presence and role of binary stellar systems. M 2-9 is a young PN with very elongated bipolar structure, that singularly yields direct information on its central stellar system. In the equator, rings detected in molecular line emission show unprecedented positional and dynamical imprints of the presence of a binary system. From those, a mass ~< 0.2 Msun was proposed for the companion of the central post-AGB star. If the presence of such low-mass companions can trigger the shaping of very elongated lobes, this would strongly supports the binary-based models. Here we propose to observe 12CO J=3-2 and 6-5 line emission to dig more deeply into the peculiar kinematics identified in the equatorial rings in M 2-9, and thus better characterize the properties of the binary system. We want to study in detail the excitation conditions of these last winds, the suggested presence of shock dynamics, and of inner warmer components, and the relation between the bipolar outflows and the equatorial rings. Post-AGB stars, Evolved stars - Shaping/physical structure Stars and stellar evolution 2017-03-09T00:00:00.000
409 2022.1.01413.S 0 Filament fragmentation in high-density environments Filaments have been studied widely in mm and sub-mm regimes (e.g. Herschel, ALMA). In environments with densities ~1E4 cm-3, the fragmentation process occurs quasi-statically, leading to the formation of equally spaced cores that inherit the kinematic properties of the parental filament. Orion A is the closest high-/intermediate-mass star-forming region, a perfect laboratory to study star birth in a high-density environment. The most compact filaments reported in this region show unprecedented high densities of >1E7 cm-3. These filaments also show extremely narrow widths marginally resolved at the current interferometric resolutions. While multiple cores are found in these high-density filaments, the fragmentation mechanism in these environments remains under debate. The project aims to investigate this fragmentation in Orion A using the extended configuration C43-4 of the ALMA 12m-array in order to achieve an angular resolution of 1" (~400 AU at ~400 pc). Using the N2H+(1-0) (Band 3) emission to trace the dense gas, we aim to resolve the velocity-coherent filaments and cores in the OMC-1 region and characterize the core formation process in this high-density environment. Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2024-05-22T11:10:03.000
410 2022.1.00916.S 0 Revealing the molecular gas content of low-metallicity low mass strongly lensed galaxies In the past decades, studies of massive high-z galaxies have revealed a strong relation between molecular gas and the rates and timescales of star formation. When exploring the lower mass range with, the help of gravitational lensing, galaxies have appeared to have less gas and/or to use their gas more rapidly than expected . This apparent gas deficit (relative to massive galaxies) can either be due to the systematic uncertainties of tracer-to-gas calibrations or to a fundamentally different mode of star formation taking place in these lower mass galaxies, but testing this can only be addressed with larger samples. Here we propose CO and dust continuum observations with ACA of six low-mass strongly-lensed star-forming galaxies at z~2-3. These observations will significantly expand the current sample of gas measurements in such objects, with the goal of improving statistics to confirm (or discard) the observed deficit. Additionally, by using two independent tracers we address some of uncertainties of tracer-to-gas calibrations. Finally, ACA and its large FOV and beam sizes is the best suited instrument to perform this survey. Lyman Break Galaxies (LBG), Gravitational lenses Galaxy evolution 2024-07-12T21:25:40.000
411 2016.2.00133.S 1093 Redshifts of bright Herschel ATLAS gravitational lenses We propose CO redshift measurements of 30 of the brightest (S500m > 0.1 Jy) strongly gravitationally lensed galaxies from the equatorial and Southern fields of the Herschel Astrophysical Terahertz Large Area Survey (H­ATLAS). These simple observations will double the sample size of H-ATLAS background source redshifts, complementing our long-term 8m-class foreground lens redshift campaigns. Our pioneering lens selection (Negrello et al. 2010 Science) has an astonishing ~100% efficiency and the gravitational amplification makes CO line detection up to ~100× faster than in unlensed surveys. Our proposed redshifts will provide spectroscopic confirmation of gravitational lensing, by finding submm redshifts that are clearly higher than the redshifts of the lensing masses. This on its own is already enough to make statistical constraints on the dark matter halo profiles. Combined with our ongoing multi-wavelength campaigns, we will start placing direct constraints on the evolving dark matter distribution of the lenses. The joint lens­source redshift distribution is a key discriminator of cosmological parameters and the evolution of dark matter haloes. Sub-mm Galaxies (SMG), Gravitational lenses Galaxy evolution 2018-12-22T20:13:54.000
412 2016.1.01398.S 108 The role of the environment in shaping the CMF in the L1641 Molecular Clouds We propose to use the C40-1 12-m array configuration in band 3 to observe 12 pre-stellar cores across the L1641 molecular clouds to derive their physical properties with regards to their local environment. Specifically we want to determine whether their formation and subsequent evolution on a filament or in the field affects the ongoing star formation process therein in any way. We will use the HCO and H13CO+ J=1-0 emission line to detect the infall motions within the cores as well as those from the local environment onto the cores and study any variations in the infall rate. We will further use the SiO (J=2-1) emission line to look for outflows towards these cores, indicative of very young proto-stellar sources and to fully characterise along with the infall motions the internal structure and dynamics the cores. We will further use the NH2D to trace the denset regions of the cores and derive their temperature and column density while the continuum emission will allow us to study the fragmentation level of the cores. Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2018-12-09T23:08:31.000
413 2019.1.01707.S 5 RESOLVING THE TWIN DISKS IN THE FU ORI SYSTEM: Episodic accretion via binary interactions? FU Ori objects are low-mass pre-main sequence stars characterized by dramatic outbursts of several magnitudes in brightness, which are not yet well understood. The archetypical FU Orionis system is composed of two young stars with a projected separation of 0.5''. Gas and dust emission have been detected around both components in previous observations. The dust emitting regions have not been resolved until now. Using ALMA, we resolved both the primary and secondary components into disks of only 11 AU in radius. The 1.3 mm emission, although only marginally resolved, yields inclination angles for each compoenent. The twin disks are near co-planar. We also found evidence of Keplerian rotation in the primary from CO kinematics. Most interestingly, we found a kinematic counterpart to a large arc-like feature previously known from scattered light. Whether this feature is infalling (accreting) or outflowing (original outburst?) is a key question we aim to address by increasing the resolution of our observations by a factor 3. The proposed observations will test for structure in the disks, as well as obtaining deeper kinematics to shed light on the mistery behind FU Ori outbursts. Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2022-10-26T22:53:02.000
414 2018.1.01409.S 146 ALMA census of the most optically-dark massive galaxies at z~>4 behind lensing clusters Deep surveys with the HST have greatly enriched our knowledge of the distant universe by discovering thousands of UV-bright galaxies at z>4. Recent studies, however, have found a new population of extremely red galaxies which remain undetected even in the near infrared (IR) with deepest HST imaging. It has been shown that most of these "HST-dark" galaxies are likely the most massive galaxies at z>4 with a mean IR luminosity of LIR~2x10^12Lsun, which is still unreachable with the current submillimeter wide-area surveys. Measuring their IR luminosity individually will put important constraints on the density of normal dusty star-forming galaxies beyond z=4 and stellar-mass function at massive end. Here we propose an ALMA census of the "HST-dark" galaxies selected in the cluster lensing fields, which is essential to confirm individually whether they are dusty star-forming galaxies at high redshift. Most importantly, we propose spectral scans towards two brightest sources detected at 850 micron from our pilot SCUBA2 ultradeep imaging, to confirm their redshifts, which is otherwise impossible even with the next generation optical telescopes such as ELT. Sub-mm Galaxies (SMG), Gravitational lenses Galaxy evolution 2020-07-20T17:03:15.000
415 2023.1.01064.P 0 Hunting for pulsars orbiting Sgr A* With the presence of the closest supermassive black hole to Earth, Sgr A*, the center of our Galaxy is an excellent and unique laboratory for experimenting with gravity. In particular, discovering even one single pulsar in orbit with Sgr A*, will provide an unprecedented opportunity to test the fundamental predictions about the nature of black holes. The mass, spin, and quadrupole moment of Sgr A* could be measured with high precision, by carefully tracking the pulsar over the course of its orbit. These measurements can be combined with event-horizon-scale imaging of Sgr A* and orbital dynamics of the S-stars, yielding a full mapping of the space-time in the vicinity of Sgr A*. Here, we propose to use the phased ALMA in Band 1 to perform the deepest search for pulsars in orbit with Sgr A* at mm-wavelengths. The new search will greatly elevate the chance for a detection compared to previous searches, providing the best opportunity by far to find a new pulsar in the Galactic Center at mm-wavelengths. It will also largely improve our capability of gauging the mysterious pulsar population in the Galactic Center, which is potentially large but so far remains mostly unseen. Pulsars and neutron stars Stars and stellar evolution 3000-01-01T00:00:00.000
416 2016.1.01423.S 68 Probing the star forming nature and co-evolutionary relations of low-luminosity quasars at z >~ 6 Previous studies of the properties of galaxies hosting quasar nuclei and the so-called co-evolution at high redshifts were strongly biased towards very luminous quasars, that prevents us from understanding the general picture of the growth of supermassive black holes (SMBHs) in the early universe. With this in mind, we here propose submm follow-up observations of recently identified quasars at z ~ 5.9-6.4 by our on-going deep optical survey with the Hyper Suprime-Cam on the Subaru telescope. These quasars are very unique as they are on average ~10 times fainter than luminous z~6-7 quasars at submm (e.g., J1148+5251). With this 12.2 hr program, we aim at detecting the [CII] line and the underlying FIR continuum emission of four low-luminosity high-z quasars. We will assess dust mass, gas mass, and SFR of the hosts, and compare these quantities with those of luminous quasars at comparable redshifts. The star forming nature as well as [CII] velocity dispersion will let us investigate the co-evolutionary relationship between the properties of host galaxies and SMBHs in a less-biased way. High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution Active galaxies 2018-05-11T20:34:32.000
417 2015.1.01332.S 87 Radiatively-Driven Implosion in the Trifid Nebula The model of Radiatively-Driven Implosion (RDI) successfully accounts for the presence of long-lived, photoionized molecular cores in the vicinity of young massive stars. RDI predicts taht the stellar radiation drives the propagation of an ionization front preceded by a convergnet shock front and a photon-dominated region into the neutral gas. This scenario is actually incomplete. Observational, quantitative comparisons are lacking: the nature of the IF remains to be established, depending on the radiation field. Important dynamical interactions at the interface between the neutral and ionized gas are neglected, while they can strongly affect the cloud evolution and the conditions of star formation. The many Cometary Globules discovered in the young Trifid nebula (M20) allow us to tackle these issues. We propose to lead a comprehensive study of two of them, in order to determine their physical and chemical structures from the central star-forming core to the surface layers, where signatures of instabilities are observed. Comparison of their properties will unveil the role of the radiation field on the physical and chemical evolution of the molecular gas. Inter-Stellar Medium (ISM)/Molecular clouds, HII regions ISM and star formation 2017-07-19T18:50:48.000
418 2016.1.00281.S 6 Imaging the Molecular Gas Outflow from Gravitationally Lensed QSO MG 0414+0534 in 20 pc Resolution Quasi-stellar objects (QSOs) are one of the most energetic sources in the early universe, and therefore the outflows from these objects are efficient metal enrichment sources at that time. However, it is not clear whether radiation (radiative feedback) or jet (mechanical feedback) is the dominant mechanism of the QSO outflows. We observed a gravitationally lensed QSO MG 0414+0534 in ALMA Cycle 2, and detected a broad (~1800 km/s) CO(J=11-10) line at a spatial resolution of ~0.3" (~150 pc). Since the CO line transition is high and the velocity width is much wider than that of the typical galactic rotation (a few hundred km/s), we consider this as the detection of a molecular gas outflow from a QSO. Since this QSO has radio jets with the size of 0.10"-0.15", imaging the molecular gas outflow with higher angular resolution and find out whether it is nearly isotropic (outflow due to radiative pressure) or bipolar (outflow due to radio jets) will tell us the dominant mechanism of the QSO outflow for the first time. We therefore request long baseline observations with the spatial resolution of 0.037" (~20 pc) at Band 7 in the CO(11-10) line. High-z Active Galactic Nuclei (AGN), Gravitational lenses Active galaxies 2019-02-02T20:06:29.000
419 2017.1.00595.S 325 DEATH STAR: DEtermining Accurate mass-loss rates of THermally pulsing AGB STARs Mass loss by a stellar wind is a decisive process for late stellar evolution. Through this wind, Asymptotic Giant Branch (AGB) stars are major contributors of synthesized elements and dust to their surroundings. The wind process is studied using dynamical wind models with the goal of developing a predictive theory of AGB mass loss crucial for stellar and galactic evolution. The most reliable method to measure mass-loss rates, and to provide constraints for the wind models, is through CO line observations, but further progress in this fundamental field is still limited by the large observational uncertainties, where the assumed size of the CO envelope is a major factor. To solve this problem we propose to directly measure the CO envelope sizes for a representative sample of typical AGB stars by observing the CO(2-1) and (3-2) emission using the ACA in stand-alone mode. With this data we will develop the most accurate description of AGB mass loss, needed over a large range of wind properties, uniquely determine the gas-to-dust ratios of the sources, and through the large bandwidths covered in band 6 and 7, provide a goldmine for legacy science for the evolved star science community. Asymptotic Giant Branch (AGB) stars Stars and stellar evolution 2019-06-25T14:19:04.000
420 2018.1.01242.S 20 Fragmentation of Serpens FIRS1: a Class 0 protostellar disk Protostellar disks are formed as a natural consequence of conservation of angular momentum during star formation. They are the cradle of both stars and planets. A fragmenting protostellar disk may cause short accretion bursts, form a stable stellar or planetary companion around the central star, or even produce massive exoplanets. Observationally, its a challenge to identify and observe a good candidate that meets the requirement for disk fragmentation. Serpens-FIRS1 is one of the few known intermediate mass protostar that has a protostellar disk massive enough to meet the requirement for disk fragmentation. We propose to observe the young, Serpens-FIRS1 Class 0 protostar in Band 3 continuum and line emissions 13CO, C18O, C17O and CN (1-0) in order to measure the physical properties of a young disk that is expected to be fragmenting, identify whether or not it has a Keplerian rotation, and constrain the mass of the central protostar. With the direct observation we will test the existing theories of protostellar disk fragmentation. Debris disks, Disks around low-mass stars Disks and planet formation 2019-11-15T19:12:42.000
421 2019.2.00236.S 10 Mapping NGC253 in dense gas tracers with ACA We propose to use the 7m+TP ACA to map dense gas tracers in bright nearby starburst galaxy NGC253 (3.5Mpc). We will target the brightest lines in 3mm band that trace dense gas (e.g. HCN, HCO+, HNC etc) at 15 arcsec resolution (spatial scale 200pc) to characterize dense gas properties over the scale that is several times better than previously achieved over the central 3kpc disk of NGC253. This source has been actively studied by other facilities in the past few years which gave us various ancillary observations within a large range of wavelengths. With these observations, we will be able to address several open science questions, including 1) how does the dense gas fraction relate to environment and star formation efficiency on ~200 pc scales? 2) how are the dense gas properties linked to the turbulent pressure? Answering these is fundamental to our understanding of star formation within dense gas from galactic down to molecular cloud scales. Starbursts, star formation, Spiral galaxies Active galaxies 2021-04-20T00:52:31.000
422 2017.1.00255.S 563 Revealing the internal structure of molecular outflows: spatially resolved observations in local LIRGs Massive gas outflows, produced by AGN and star-formation (SF), play a major role in the regulation of the stellar mass and central black-hole mass growths. They are ubiquitous in galaxies with strong SF and AGN, but little is known about the physical processes that control their evolution and impact on the host galaxy. We propose to address this issue by obtaining high-spatial resolution (60 pc) CO(2-1) observations for a representative sample of 18 (15 new + 3 archive) local LIRG systems (22 individual galaxies) known to host outflows. We will resolve the clumpy internal structure of the molecular phase of these outflows, and, together with our knowledge on the ionized and neutral atomic phases available from ancillary integral field spectroscopy data, we will be able to investigate the key aspects that define the structure and evolution of outflows: (i) mass, kinetic energy, and momentum evolution of the molecular gas within the outflow; and (ii) impact of possible SF occurring within the outflow through the extra injection of energy and momentum. With this proposal, we will overcome the statistical limitations of previous studies based on just a few cherry-picked galaxies. Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Active galaxies 2019-05-29T16:10:22.000
423 2015.1.00139.S 4 Where is the cometary chlorine? We propose a new probe of cometary ice evolution in protoplanetary disks: chlorine. Its chemistry in molecular gas is well known, and the main carrier HCl easily observed. The journey of chlorine from ices in protostellar cores to comets is currently a puzzle. Comets yield upper limits on their HCl to H2O ice ratio of order 0.0001, while protostar studies infer values an order of magnitude higher. It is not known whether the HCl ice evaporated in the protoplanetary disk, or was converted and locked into some unknown ice species. The answer lies in the gas-phase chlorine abundance in disks. We will use ALMA observations of HCl in a young Solar System analog to determine whether chlorine in disks has returned to the gas, as suggested by cometary ices. This study is timely, as the Rosetta spacecraft at comet 67P will soon provide the strongest constraint to date of the HCl to H2O ratio in a comet. Disks around low-mass stars, Solar system - Comets Disks and planet formation 2017-10-21T01:33:08.000
424 2019.2.00062.S 61 Unlocking the Potential of the Most Definitive Molecular Tracer of UV-Enhancement: l-C3H+ The recently-discovered interstellar molecule l-C3H+ appears to be the most sensitive and definitive molecular tracer of enhanced UV-flux ever observed in the ISM. Extensive, deep searches for this species in dozens of sources show its presence exclusively in UV-enhanced regions. Yet, our understanding of the spatial distribution of the molecule within these sources, and the excitation conditions (and abundances) in previously-observed regions, is sorely lacking. Here, we propose ALMA observations following up on our prior ALMA detection of l-C3H+ in the Horsehead PDR region. Our 12m observations revealed an unexpected large-scale distribution of l-C3H+ which is clearly missing short spacing data which the ACA can provide. We also request follow up observations of Mon R2 which shows no compact structure and thus requires ACA data to reveal extended emission. We wish to better understand the spatial distribution, abundance, and excitation of this potentially transformational molecule in our ability to probe the extent of UV-enhanced flux in these and other key regions. The results will be used to refine state-of-the-art PDR chemical modeling codes and inform related ALMA proposals. Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) ISM and star formation 2022-09-29T21:48:09.000
425 2011.0.00319.S 0 Low luminosity millimeter survey behind a strong lensing cluster We propose to perform continuum observations at 1.3 mm (Band 6) in the strong magnification region (x > 10) of the massive cluster Abell 1689. We can cover a survey area of 4 arcmin2 down to an intrinsic (lensing-corrected) sensitivity of 0.05 mJy (4sigma). We expect to detect ~ 12 continuum sources according to current models. This will allow us to complement the studies of brighter continuum sources and derive their relative contribution to the star-formation rate and cosmic infrared background. At the same time, we will measure the CO line flux of 3 submm galaxies at z=2.5-2.7 discovered with SCUBA in this field, and we will cover the wavelength of the CO line for a sample of 30 other sources at 2.5 Gravitational lenses, Sub-mm Galaxies (SMG) Cosmology 2013-09-07T11:37:41.000
426 2017.1.01545.S 230 The first molecular line inventory in hybrid disks The transition from the late phase of protoplanetary disks to young debris disks remains a poorly explored evolutionary stage of planet-forming disks. The new class of "hybrid" disks, recently revealed by our team, includes disks exhibiting debris disk-like dust properties, but having primordial gas content. These disks may represent the protoplanetary to debris disk transition. In order to establish how the physical and chemical properties evolve, we propose to study all four hybrid disks discovered so far, and four evolved Herbig Ae systems with relatively low gas content as comparison targets. The observations will provide the first inventory of the most important molecules in these disks. We will characterize their morphology and kinematics, and perform a detailed chemical analysis using our ANDES and ALCHEMIC chemistry codes adapted to these disks. Our program will reveal the physics of an independent evolutionary path for the gas component around A-type stars. The longer than anticipated survival of gas in hybrid disks will have important consequences for planet formation, providing material for the formation of gaseous planets even after the canonical 10 Myr of evolution. Debris disks Disks and planet formation 2019-07-20T13:38:11.000
427 2015.1.01495.S 80 Are the most massive z >4 galaxies hidden from HST ? Our current understanding on the cosmic star formation history at z > 4 is primarily based on UV-selected galaxies. A critical question is then whether we are missing a significant population of massive, UV-faint galaxies. By crossmatching HST/WFC3 and IRAC data in the three CANDELS-Herschel fields, we perform a systematic search of galaxies which are bright in IRAC but are not detected in the WFC3 H band, i.e., H-dropouts, which are likely at z > 4 where the H band probes the rest-frame UV. In total, we identify 64 H-dropouts down to [4.5] < 24, corresponding to M*~10^{10.8} Msun at z > 4. Both photometric redshifts and stacked infrared SED suggest that most of them are at z > 4, with LIR~2*10^{12} Lsun. These galaxies likely represent 30-40\% of the most massive galaxies at z > 4, but were completely missed in previous studies based on either UV or near-infrared selected samples. An ALMA 870 um census is crucial to confirm individually that they are high-redshift dusty sources, and explore star formation properties for this unique sample, which is essential to have a complete understanding of massive galaxy formation in the first 1.5 Gyr of the universe. Sub-mm Galaxies (SMG) Galaxy evolution 2017-09-29T02:45:20.000
428 2011.0.00340.S 0 Searching for H2D+ in the disk of TW Hya v1.5 Most of the mass in a protoplanetary disk is represented by molecular gas concentrated near the midplane, but it is exceedingly difficult to find clear signatures of gas in such locations. Emission lines from deuterated species like H2D+ and D2H+ provide the best - and perhaps only - diagnostics for probing gas in the disk midplane, and thereby learning about the local kinematics and ionization fraction. We propose to search for the ortho-H2D+ 372.421 GHz line toward the well-studied, nearby disk around TW Hya with the "compact" configuration. The proposed observation will allow us to detect ortho-H2D+ fractional abundances down to 30 mJy km/s, more than an order of magnitude below present upper limits. This corresponds to ortho-H2D+ fractional abundance of 1e-13 which is below any published model predictions. A detection will constrain the ionization fraction in the cold disk midplane and help probe the gas kinematics and the viability of MRI-based disk transport physics in this region of the disk. A non-detection will challenge the existing models, helping improve our understanding of accretion flows in the disk midplane. Disks around low-mass stars, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) Disks and planet formation 2013-12-06T19:55:00.000
429 2019.1.01408.S 6 Unveiling the formation scenario of born-again PNe through ALMA observations Born-again planetary nebulae (PNe) are thought to be evolved objects that have experienced a very late thermal pulse (VLTP) when the central star was on the white dwarf track. The VLTP event produces an ejection of processed H-deficient material that interacts with the old PN. Optical and IR studies suggest that the evolution of the H-deficient material is fast with timescales of ~20-100 yr. Thus, these objects offers the possibility of studying the formation and evolution of dust and molecules in human timescales. We propose to study the spatio-kinematic properties of the youngest born-again PNe in which molecular emission has been detected but not resolved. Our observations will bring insights in the early formation of non-isotropic ejections in evolved stars and will constrain the current formation scenario of born-again PNe. Asymptotic Giant Branch (AGB) stars, Post-AGB stars Stars and stellar evolution 2022-07-27T14:57:14.000
430 2016.1.00171.S 790 Understanding ISM physics at high-z: cold gas and CO excitation for 75 normal and starburst galaxies at 1.1<z<1.7 We propose to observe CO[2-1] for 75 galaxies with ALMA Cy3 measurements of CO[5-4] and 500um rest-frame dust continuum (hence Mdust), and with secure LIR from Herschel (hence also Tdust), roughly evenly divided between main sequence and starburst galaxies, towards the SFR density peak at 1.1 Starburst galaxies, Galaxy structure & evolution Active galaxies 2018-02-13T18:39:41.000
431 2021.1.01644.S 19 Probing the Excitation and the Mass-Luminosity Conversion Factor of the Dense, Star Forming Gas Across Galaxy Disks We propose ACA Band 6 observations to map the J=3-2 line emission of the canonical, extragalactic dense gas tracers HCN and HCO+ in 9 nearby disk galaxies. The target fields cover a broad range of environmental conditions. Our main goal is to constrain the excitation and, more generally, the physical conditions of the dense, star forming gas across disks. In external galaxies, such studies were largely focused on bright galaxy centers or (U)LIRGs at low, kpc-scale spatial resolutions or in very compact nuclear regions. This proposal will multiply the number of galaxies and range of environments at sub-kpc scales. Our ultimately goal is to link: (1) the excitation conditions of the dense, star forming gas; (2) the cloud properties derived from physically-motivated radiative tranfer modelling; (3) and the environment the clouds live in. Further, line ratios are essential to constrain the HCN conversion factor from which dense gas masses are derived. We will revisit the scaling relations between dense gas and star formation that help us differentiate between competing models for how star formation is regulated across galaxies. Spiral galaxies, Giant Molecular Clouds (GMC) properties Local Universe 2023-09-12T14:39:24.000
432 2015.1.00453.S 18 [HCN]/[HNC]: A fundamental problem in Astrophysics The two isomers of the H-C-N system, hydrogen cyanide (HCN) and hydrogen isocyanide (HNC), are commonly used as tracers of the dense molecular gas in Galactic and extra-galactic research. Moreover, the [HCN]/[HNC]is considered as a chemical diagnostic for the gas temperature. The full comprehension of the HCN and HNC chemistry is therefore of paramount importance in the study of the physics and chemistry of the interstellar gas. In the latest years, gas phase and gas-grain chemical models have increased in complexity and incorporated new laboratory measurements to provide an accurate and complete description of their chemistry. However, high spatial resolution and high sensitivity data are needed to test these models. Based on our IRAM 30m 2D spectral survey, we have measured an anomalously high [HCN]/[HNC]ratio (larger than 10) towards the ultracompact HII region Mon R2. Time dependent effects and photodesorption have been proposed as possible explanations. Our goal is to determine the [HCN]/[HNC] ratio at a spatial resolution of 1-arcsec in order to discern between these two interpretations and investigate the influence of UV photons on the chemistry of the H-C-N system. Astrochemistry ISM and star formation 2018-04-24T20:17:47.000
433 2023.1.00905.S 0 HII Regions and Galactic Chemical Evolution The present-day chemical structure of the Milky Way disk constrains models of Galactic chemodynamical evolution. HII regions, the sites of recent massive star formation, are a bright trace of Galactic metallicity structure. Galactic disks are expected to be well-mixed, but recent observations of HII regions in the Milky Way and other galaxies have revealed unexpected azimuthal variations in the metallicity structure of these galaxies. Several competing theories have been suggested to explain these observations. We propose to observe isotopologues of CO and CN with the ALMA Compact Array (ACA) toward molecular gas associated with HII regions across the Galactic disk. We will use these data to derive 12C/13C isotopic ratios, which, when compared with the metallicities of the associated HII regions, will allow us to distinguish between the competing theories for the azimuthal metallicity structure. We will simultaneously derive 14N/15N and 16O/18O isotopic ratios, which further constrain models of Galactic chemical evolution. HII regions ISM and star formation 2025-04-29T17:28:52.000
434 2022.1.00591.S 13 The 'Missing Link': Gas Accretion Flows in the Galactic Bar toward the Central Molecular Zone We propose to observe 25 clouds in the Galactic bar with gas temperatures of tens of K and broad lines (>~10km/s) - these clouds are the best candidates for the gas flow that feeds the Central Molecular Zone (CMZ) of our Milky Way. Whereas the CMZ is a well studied region at all wavelengths (including the supermassive black hole Sgr A* and the vigorous star forming region Sgr B2), the streams that feed the CMZ have largely been neglected. Modelling shows that the gas likely follows x1 and x2 orbits in the bar potential, enforced by the bar potential, with gas accretion at various points and cloud-cloud collisions from dynamical effects like (self-)intersecting orbits and accretion overshooting. We propose to probe these processes by observing molecular lines that trace physical parameters such as shocks, turbulence, temperature, ionization etc. The ACA+TP is the perfect telescope for our study as it allows us to probe relatively large regions at molecular clump resolution with adequate sensitivity. The data will provide an invaluable grid of cloud properties for improved detailed dynamical models of the inner Galaxy. Galactic centres/nuclei Active galaxies 2024-05-17T00:00:00.000
435 2018.1.01301.S 42 A Survey for CO(3-2) in HS1549+19, the most overdense protocluster known at z>2 We propose to map the HS1549 z=2.85 protocluster in the CO(3-2) line. HS1549 is amongst the richest system in Lyman-break galaxies and Lyman-alpha emitters at z>2 known. We choose 35 pointings which cover all highly significant SCUBA-2 sources lying within high density subregions in the protocluster (likely cosmic web "nodes"), and the intervening area covered by the 70 band-3 ALMA primary beam. Our pilot NOEMA pointing targeted an especially active subregion, with 4 QSOs and 3 bright submm sources. We detected 6 sources in CO(3-2), but cannot easily interpret the results more globally in terms of galaxy density and CO luminosity function. This ALMA program will provide an efficient view of the star forming gas in a massive protocluster to understand the assembly of one of the richest regions in the Universe, but also as a lever on the CO(3-2) luminosity function and its variations within the protocluster, scaled by the galaxy density in this system. This is a resubmission of a C-rated cycle 4 proposal which has not received any data yet. The proposal has been updated, to include our wider field SCUBA-2 map over the Subaru mapped extended pro cluster. Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) Galaxy evolution 2020-08-27T20:29:51.000
436 2013.1.01016.S 5 An ALMA investigation of the environment around the young 2M1207b planetary mass object At the distance of only 55 pc, the TW Hyadrae association harbors one of the most intriguing astrophysical systems: a young 8 Myr-old planetary mass object orbiting a low mass brown dwarf at a radius of 40 AU. Thanks to its proximity, very young age, and angular separation between brown dwarf and planetary mass object, the 2M1207 A & b system is probably the best candidate to investigate the physical environment of a very young planetary mass object down to a fraction of Lunar mass in dust mass. We propose to use the very high sensitivity and angular resolution provided by ALMA in Cycle 2 to search for dust thermal emission in the system. These observations will set tight constraints on the presence of material around a planetary mass object at the last stages of its formation. The characterization of the more massive disk known around the low mass brown dwarf will shed light on the structure of disks surrounding young objects close to the deuterium burning limit. Disks around low-mass stars Disks and planet formation 2015-11-24T18:06:41.000
437 2017.1.00107.S 1939 Probing the Grain Growth Signatures in rho-Ophiuchi Young Stellar Objects When and how do interstellar dust grains with micron-size grow to millimeter-size in circumstellar disks around young stellar objects (YSOs)? Previous observations have revealed the grain growth signature in the majority of the disks around Class II sources. On the other hand, our recent analysis of the Class 0 sources shows no firm evidence of grain growth in these sources. These results suggest that the effect of grain growth on the dust opacity index (beta) becomes prominent before the Class II stage, but no earlier than the late-class 0 stage. We, therefore, hypothesize that the grain growth signature becomes significant in the circumstellar (pseudo-)disks around Class I YSOs. In order to test this hypothesis, we plan a dedicated survey for beta in circumstellar (pseudo-)disks around various evolutionary stages of YSOs from Class 0 to early Class II in the rho-Ophuchi molecular cloud. ALMA is an ideal instrument for conducting this survey because of its superb sensitivity. We plan to obtain the continuum data in Band 6 (1.3 mm), Band 4 (2 mm), and Band 3 (3.3 mm), derive the beta values, and constrain the earliest signature of grain growth. Low-mass star formation ISM and star formation 2019-10-19T22:19:19.000
438 2017.1.01177.S 18 Connecting the CO and neutral hydrogen gas in DLA host galaxies at z=0.45 and z=0.59 We propose to use ALMA to detect and image the molecular gas in the host galaxies of two 21-cm HI DLA systems (at z=0.45 and 0.59) detected in a pilot study with the Australian SKA Pathfinder (ASKAP) radio telescope. Our main goal is to connect the neutral atomic (HI) and molecular (CO) gas within individual galaxies at a lookback time of 5-6 Gyr, and so provide a more complete picture of the typical baryonic gas reservoir within normal galaxies at this epoch. Observations of the CO (2-1) emission line will allow us to characterise the host galaxies of these z ~ 0.5 DLA systems through measurements of the mass and kinematics of their molecular gas, as well as measure the impact parameter of the sightline along which we see 21-cm HI absorption. Finally, both our targets are on sightlines to radio-loud QSOs that are bright (0.5-1.0 Jy) unresolved continuum sources at 150 GHz, allowing us to seach for CO (2-1) absorption along the same sightline as the HI DLAs. Damped Lyman Alpha (DLA) systems Cosmology 2019-02-21T14:37:59.000
439 2013.1.00999.S 4 Lensing Through Cosmic Time: ALMA Constraints on "Normal" Galaxies in the HST Frontier Fields We propose ALMA Band 6 imaging (FWHM=1.3", 0.35mJy @5sigma) of the first 4 massive strong-lensing clusters in the HST Frontier Fields, leveraging their >5-10 magnification to study high-z galaxies over the inner ~4 arcmin^2. These clusters have a wealth of ancillary ground/space-based radio-to-X-ray imaging, 1000s of high-quality spectroscopic and photometric redshifts, and exceptional lensing-mass models. Yet these important targets lack strong submm constraints. Our observations will allow (1) a probe of the 1.1mm number counts and luminosity function ~5-10x below published estimates, (2) individual and statistical characterization of high-z star formation via SED fitting/stacking of 10s-1000s of high-z galaxies and source reconstructions, (3) dust continuum constraints on the lensing cluster galaxies and ICM, and (4) a critical benchmark for future lensing-related projects with ALMA. The proposed data will inform us about how star formation proceeded in the early universe. This proposal is a large extragalactic Chilean key project with broad community support and funding, and considerable international expertise (including many on the CLASH science team). Lyman Break Galaxies (LBG), Gravitational lenses Galaxy evolution 2016-06-17T00:00:00.000
440 2015.1.01584.S 13 A statistical study of molecular clumps in the triggered star-forming region M17SW We propose a multi-line observation of dense molecular clumps toward M17SW. M17SW is a core of gint molecular cloud (GMC) interacting with an expanding HII region. The observation aims a statistical study of dense molecular clumps to confirm a triggered star formation (TSF) by the HII region. We will derive the spatial distribution of the size and the density using dense gas tracers such as H13CO+, HCN, and HCO+ in Band 3. This result will establish the relation between the HII region and the warm and dense shell near the ionized front through comparing with the numerical simulation. In addition, we will derive the initial fractal dimension of M17SW and the power index of the clump mass function (CMF) for the dense shell. Walch et al. (2013) suggest a unified model for TSF that predict the lower index of CMF for the TSF region is small when the initial fractal dimension of the GMC is low. The fractal dimension of M17SW would be low because it consists of clumpy structure. If the CMF for the TSF region of M17SW has flatter slope, this result supports and confirm the unified TSF model. High-mass star formation ISM and star formation 2017-09-08T13:06:38.000
441 2016.1.00291.S 5 The jet/outflow system in BHR71 The interstellar medium (ISM) is constantly out-of-equilibrium, with energy continuously injected in various forms: mechanical, photons, or cosmic rays. The propagation of shocks is ubiquitous in the ISM, where it represents an important part of the mechanical energy input. In particular, shocks are generated by the birth of stars in the form of jets and bipolar outflows, where they play an important role in the evolution of the interstellar medium. The study of jet/outflows interactions is paramount to understand the star formation processes and scenarios, but also to evaluate the impacts of the shocks on the local interstellar medium. Unfortunately, in low-mass protostellar environments, these tasks are made difficult by the faintness of the jet component. For the first time, we propose to observe the jet/outflow system in the low mass protostellar outflow BHR71, where our complementary observations strongly suggest the presence of a high-velocity jet. With the requested observations, we will characterize the shocks associated to the jet and outflow, study their energetic and chemical impacts on the environment, and also evaluate their efficiency in accelerating cosmic rays. Outflows, jets and ionized winds, Intermediate-mass star formation ISM and star formation 2019-06-12T00:00:00.000
442 2018.1.00897.S 25 Can we trust 'dense gas tracers' to trace dense gas? The optical depth of "dense gas tracers" plays a main role in setting their effective critical density, and so their density sensitivity. But because the optically thin isotopologues used to probe optical depths are very faint, good measurements of the optical depth are rare outside the Milky Way and the brightest starbursts. To improve this situation, we propose to use ALMA Band 3 to simultaneously measure the emission coming from dense gas tracers, HCN and HCO+, and their isotopologues, H13CN and H13CO+, in the center, bar, and off-nuclear star forming region of the nearby galaxy NGC 3627. NGC 3627 is a barred spiral with inner structure that resembles those in the Milky Way. These observations will allow us to make the among first measurements of the optical depth and effective critical density of the main extragalactic dense gas tracers in a normal star-forming galaxy. These measurements are crucial to understand what gas is traced by these lines, and how to use HCN or HCO+ luminosity to dense gas mass. The faint nature of this lines make this an experiment that only ALMA can do. Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2020-11-01T15:36:18.000
443 2016.1.00455.S 82 A CO Survey toward the Host Galaxies of Long-duration Gamma-ray Bursts Long-duration gamma-ray bursts (GRBs) are though to be associated with the explosions of massive stars, and are expected to be a new tool to probe star-forming activity in the distant universe. To establish the link between GRBs and star formation, it is necessary to understand the properties of GRB hosts in terms of molecular gas. Previous studies suggest a higher star-forming efficiency (SFE) and shorter gas depletion timescale in GRB hosts compared to local and z ~ 1-2 star-forming galaxies. However, the sample size is limited (only three hosts with CO detection). In addition, there is an uncertainty on molecular gas mass from the assumed CO-H2 conversion factor, especially for low-metallicity hosts. We propose CO and dust continuum observations toward 6 GRB hosts. We select targets with metallicity higher than the solar value, which reduces the uncertainty of conversion factor, offering the best sample for molecular gas study. Our goal is to examine whether GRB can be used as an unbiased tracer of star formation. We study the properties of GRB hosts (molecular gas mass and SFE, gas depletion timescale, and obscured star formation) by comparing with other star-forming galaxies. Gamma Ray Bursts (GRB) Cosmology 2018-03-25T10:40:15.000
444 2016.2.00164.S 18 An Organic Exosphere on 1 Ceres? Ceres, the target of the Dawn mission, is known to have a warm, liquid-bearing, interior that is rich in volatiles. The detection of aliphatic organic matter on an aqueously-altered body admits the possibility that extensive prebiotic synthesis could have occurred on Ceres, an object of intense interest for the study of primitive bodies and astrobiology nowadays. Observations of water absorption and hazes on Ceres point to the existence of an exosphere on this dwarf planet. Although organic species are present on the surface of Ceres, mechanisms such as sputtering by Solar wind particles, cryovolcanism and thermal sublimation would allow their removal into space, forming an organic exosphere. Based on a tentative detection of HCN emission on Ceres with the JCMT, we wish to further explore the possible organic component of this exosphere and determine the viability that the surface molecules originate from cometary impacts using the ACA 7-m Array. Solar system - Planetary atmospheres, Solar system - Asteroids Solar system 2018-10-18T13:48:34.000
445 2016.1.00805.S 12 Origin and variability of the (sub-)mm continuum emission in the changing-look AGN Mrk590 The dramatic disappearance of the optical broad emission lines in Mrk 590 between the years 2006 and 2012, along with the concurrent fading of its radio to X-ray continuum fluxes, suggest that the AGN was turning off. Studying such extreme behavior in these rare changing-look AGNs can provide profound insight into black hole fueling, accretion and energetics. The goal of our highly ranked Cycle 3 proposal was to measure the (sub-)mm fluxes of Mrk 590 during its low accretion state, providing a crucial reference for variability studies should the AGN reignite. Recent Swift observations show the X-ray fluxes steadily increasing in strength, as expected if the AGN is turning on again! This is an unprecedented opportunity to witness this rare event as it occurs. We request continuum flux measurements at 110, 343, 470, and 670 GHz in Cycle 4, to compare with our Cycle 3 fluxes and determine if they are also strengthening. This will be the first study of (sub-)mm flux variability in a changing-look AGN, to investigate the origin of the (sub-)mm continuum emission, its spatial extent and its energetics relative to nuclear components emitting at other wavelengths. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2017-11-21T12:40:55.000
446 2015.1.01235.S 35 The core mass function in a far-outer Galaxy cloud The distribution over mass of stars at birth, the initial mass function (IMF) is one of the most important parameters in star-formation research. It is still not clear what determines the IMF, nor whether the IMF is the same for every star forming region. It does seem, however, that the IMF is set very early on by the masses of the molecular cores out of which the stars form. The core mass function (CMF), and by consequence the IMF, may however depend on the physical and chemical properties of the environment. So far, CMFs (and, with few exceptions, IMFs) have been determined in molecular clouds (and star clusters) in the solar neighbourhood and the inner Galaxy. We propose to determine the CMF in a molecular cloud in the far-outer reaches of our Galaxy (galactocentric distance 16 kpc), where conditions are very different from the inner Galaxy. We do this by continuum and line observations of 94 clumps identified from Herschel 250 micron images of this cloud; each clump is assumed to contain one or more cores, of sizes comparable to the ALMA beam. We aim to be able to detect cores with masses of the order of the Jeans mass (1 Msun). Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2017-06-22T17:17:30.000
447 2011.0.00108.S 0 X-ray irradiated dense molecular medium in the active nucleus of NGC 1097 We propose to study the physical and chemical properties of dense molecular gas in the central kpc region of the nearby active galaxy NGC 1097 at 110 pc (1".6) resolution. NGC 1097 hosts a type-1 Seyfert nucleus with a circumnuclear starburst ring with a radius of 10". Furthermore, the nuclear molecular gas condensation exhibits unusually elevated HCN/HCO+ brightness ratios in both J=1-0 and 3-2 transitions and CO(2-1)/CO(1-0) ratios, which are never seen in starburst galaxies. Therefore, NGC 1097 is one of the best showcases demonstrating the physical and chemical diversity of the dense molecular medium as a function of heating sources, i.e., AGN and starburst in ~100 pc resolution even in cycle 0 ALMA. We have selected a set of key dense molecular tracers to describe physical and chemical aspects of AGN and starbursts, i.e., HCN, HCO+ , CS, and SiO, which can be efficiently observed in Band 3 and 7, thanks to the superb spectroscopic capability of ALMA. With these measurements, we will address the following issues: (1) abundance ratio variations of HCN, HCO+, and CS: Is the elevated HCN/HCO+ ratio caused by X-ray irradiated dense molecular medium? (2) detecting the SiO emission in the active nucleus: Is the central dense gas condensation a XDR like NGC 1068? (3) search for vibrationally excited HCN emission: what is the role of radiative pumping in the 100 pc region around AGN? (4) kinematics of dense clouds: can we see the inflow of dense clouds to the nucleus, or outward motion driven by a putative jet/outflow from the nucleus? By answering these key questions, we will renovate our current view on the physical and chemical properties of active galaxies. Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2013-04-24T07:55:00.000
448 2015.1.01151.S 45 The first glimpse of CO 2-1 in z=1.6 cluster galaxies We propose Band 3 observations for a stellar mass-limited sample of spectroscopically-confirmed cluster galaxies to detect CO(2-1) for the first time within z=1.6 massive cluster environments. CO(2-1) traces the total molecular gas reservoir that fuels star formation (SF), allowing us to place the first constraints on the evolution of the gas fraction within the highest density regions at z=1.6. This epoch marks the peak in the integrated SF of the Universe, and the pivotal point when SF migrates to cluster cores. Comparing CO within cluster galaxies to the field at z~1.5 will help us address the crucial question: what governs SF over cosmic time and in various environments? We target 3 massive spectroscopically-confirmed clusters (70 members) from the SpARCS survey, which has so far returned ~20 high-z clusters. With a minimum of 18-24 detections, we expect to more than triple the current sample of CO measurements in cluster environments in 13.3 hours total. All 3 clusters also have Cycle 21 HST time (16 orbits) for additional spectroscopy and imaging. This redshift represents the most distant epoch at which it is possible detect the CO(2-1) transition with Cycle 3. Galaxy Clusters Cosmology 2017-05-11T21:13:08.000
449 2022.1.00313.S 0 Planet formation in AB Aur In order to look for planets at earlier evolutionary stages, indirect evidences are invoked, such as rings of dust-free regions within dense disks, or spiral patterns. In the previous study of the molecular spirals (0.14", 12CO 2-1) within the AB Aur dust cavity, the existence of an embedded object at a radius of 30 au (P1) and an additional object at a radius larger than 90 au (P2) have been suggested. At P1, two evidences of embedded object have been detected: 1) recent SPHERE/VLT image at near infrared (NIR) reveals a twist feature; 2) ALMA reveals CO bright clump in several velocity channels deviating from Keplerian rotation. At P2, a clump-like protoplanet has been newly reported at NIR continuum with Halpha emission. Using Band 6, we propose to simultaneously measure the gas content in the spirals by a high sensitivity, high resolution search for 12CO, 13CO and C18O 2-1 in these spirals, and to test the possible existences of Circum-Planetary Disks (CPDs) at P1 and P2 both kinematically, using 12CO 2-1, and in continuum taking advantage of the high resolution (0.04"-0.06") and sensitivity to dust (9 microJy/beam). Disks around low-mass stars, Exo-planets Disks and planet formation 2024-11-21T00:58:03.000
450 2022.1.00951.S 6 Revisiting the slope of black hole scaling relations for spiral galaxies The evolution of massive black holes (MBH) and their host galaxies appear to be closely connected as several tight scaling relations suggest. It is still debated what exact evolutionary path galaxies of different morphology follow. Sahu et al. 2019 compiled MBH masses derived from different dynamical tracers and showed that early-type and late-type galaxies (ETG/LTGs) follow scaling relations with very different slopes. When only using the subset of MBH masses derived from cold gas, we noticed that the LTGs significantly deviated from the Sahu et al. 2019 relations. We propose to use ALMA observations to derive robust dynamical measurements of MBH masses in a sample of 12 nearby LTGs. The high resolution of ALMA observations will map the kinematics of the rotating nuclear molecular gas disk, resolve the black holes' sphere of influence, and allow us to measure the MBH mass precisely. Our measurements will provide new constraints (1) on the slope of the LTG scaling relations and the cause of the mentioned discrepancy, (2) on the pitch angle - MBH scaling relation as diagnostic tool for low-mass LTGs and (3) on the secular evolution of LTGs with respect to their central black hole. Spiral galaxies, Galactic centres/nuclei Local Universe 2024-06-23T16:47:51.000
451 2022.1.01163.S 9 Simultaneous Monitoring of Stellar Flares with ALMA and TESS to Discover Space Weather Environments of Exoplanets The high energy emission from stellar flares calls into question the habitability of planets orbiting M-dwarf flare stars. While the recently-discovered population of millimeter flares closely traces this high energy emission, the relationship to the optical wavelengths at which flares are usually observed remains unclear. Here, we propose the first ALMA observations of M-dwarf flares alongside simultaneous optical monitoring at 20 sec cadence with TESS. The multi-wavelength observations will determine for the first time (1) if higher rates of millimeter flaring than optical flaring are typical of M-dwarf flare stars, informing the space weather environments of terrestrial planets. (2) The proposed observations will also quantify the degree of optical decoupling to millimeter flares for a select handful of large events observed simultaneously in both wavelengths. Disks around low-mass stars, Exo-planets Disks and planet formation 2024-07-12T14:34:40.000
452 2013.1.01113.S 6 Probing the physics and chemistry of the candidate first-hydrostatic core Chamaeleon MMS1 The First Hydrostatic Core (FHSC) constitutes one of the first milestones in theoretical models of low-mass star formation. This proposal aims to elucidate the nature of the low-luminosity infrared source Chamaeleon MMS1 (Cha-MMS1), to help resolve the dichotomy of whether it is an FHSC or merely a low-luminosity Class 0 protostar (VeLLO). We propose to map at high angular resolution the spectroscopic signatures theorised to be characteristic of FHSCs and VeLLOs, including CO and CS emission from the outflow and H2CO, CH3OH and HC3N emission from the hot core. Based on current numerical simulations, the detection of a spatially compact (<200 AU), low-velocity CO outflow will consitute strong evidence in favour of Cha-MMS1 being the first confirmed FHSC. On the other hand, the detection of H2CO and/or CH3OH inside the core will provide evidence for the presence of a (>100 K) hot corino, which would instead identify Cha-MMS1 as a Class 0 protostar. High spectral-resolution CS line profile observations will provide information on the infall and outflow properties of the source. HC3N will be observed as a probe of carbon-chain chemistry. Outflows, jets and ionized winds, Low-mass star formation ISM and star formation 2016-08-12T18:01:07.000
453 2021.1.00363.S 4 Star Formation in the Brick & Cloud C: Combining JWST with ALMA The Brick, G0.253+0.015, is the densest, most massive infrared dark cloud in the Galaxy. It appears to be highly deficient in star formation, yet the entire cloud mass exists above star-formation thresholds measured in local clouds. With a gravitationally bound mass of ~10^5 Msun, this cloud is likely to form a high-mass cluster, but we see it now at an early, pre-stellar stage. However, open questions remain: has this cloud been forming low-mass stars, below our detection threshold? If it were forming a population of low-mass YSOs, like those seen in local clouds (e.g., the Taurus molecular cloud), they would not yet have been seen. What suppresses star formation in this cloud? These questions have motivated two JWST programs mapping this cloud and its neighbor, Cloud C, to search for low-mass YSOs and measure the density structure of the cloud. We propose to obtain ALMA observations that will match JWST's spatial resolution, obtain comparable sensitivity to Class II objects, and obtain superior sensitivity to deeply-embedded Class 0/I objects. Combining JWST with ALMA data, we will assemble a complete view of these clouds' recent and ongoing star formation activity. Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2023-09-21T23:21:14.000
454 2017.1.00172.S 70 Stellar feedback and physical conditions of molecular gas around low-metallicity super-star clusters Feedback from accreting black holes and from massive stars and supernovae has become a cornerstone for our understanding of galaxy evolution. However, there are currently few observational constraints for stellar feedback, especially for the effect of metal-poor young, massive, super-star clusters (SSCs). In order to quantify physical conditions in the molecular gas around SSCs, we propose 12CO(1-0), 12CO(2-1), 12CO(3-2), 12CO(4-3), and [CI](1-0) maps at 40 pc resolution of a low-metallicity dwarf starburst, NGC 1140 (0.3 Zsun), hosting 6-7 SSCs; these transitions have already been detected with single-dish measurements. Our proposed observations will characterize the molecular gas morphology, kinematics, gas temperature, H2 density, and atomic carbon abundance in the metal-poor interstellar medium (ISM) surrounding the SSCs. We will compare our results with recent models of ISM chemistry and star formation, to better quantify the effects of stellar feedback for input to galaxy evolution models. ALMA will provide an observational perspective on the effects of stellar feedback in an extreme environment which may be representative of the ISM in high-redshift galaxy populations. Dwarf/metal-poor galaxies Local Universe 2019-09-14T18:17:38.000
455 2018.1.01240.S 13 Mapping the molecular gas reservoir of a recently-quenched galaxy Our ALMA survey of massive z~0.6 post-starburst galaxies has revealed that recently-quenched galaxies can retain significant- and puzzling- molecular gas reservoirs. Our detection of >10^10Msun of gas in SDSS J0912+1523 represents the first detection of molecular gas in a quenched galaxy outside of the local universe, and indicates that quenching does not require the total removal or depletion of molecular gas. However, we still do not understand the physical processes preventing this abundant gas from forming stars. Here we propose follow-up observations of this galaxy to map its gas distribution and velocity structure using high-resolution CO(2-1) data, and to probe the gas density using CO(4-3) data. These observations-- in conjunction with the stellar kinematics, 1.4 GHz continuum, and high-resolution imaging we have obtained for this target-- will allow us to assess the gas density, compare the stellar and gas morphology and kinematics, search for signs of merger activity or outflows, and place this galaxy on the Kennicutt-Schmidt relation. This analysis will help constrain the physical mechanisms that quenched star formation in this galaxy without depleting the molecular gas. Galaxy structure & evolution Galaxy evolution 2020-02-16T17:55:18.000
456 2023.1.01504.S 0 Neptune's High-Altitude Wind Chill from ALMA We know much less about the atmosphere of Neptune, and the other ice giant planet Uranus, compared to other planets like Earth and Jupiter. Processes such as convection can generate storms and affect a planets upper atmosphere that is also strongly influenced by its seasons, which for Neptune last 40 years. Therefore, studying the motion and structure of a planet's upper atmosphere investigates the relative strength of effects operating over various timescales and across large distances between different planetary region. We propose to study the dynamics of Neptune's stratosphere, where the competition between seasonal effects and processes such as convection can affect different large-scale circulation patterns present in the atmospheres of Earth, Jupiter, and even exoplanets. The ice giants are considered an analogue for a large fraction of exoplanets discovered and ALMA's spectral and spatial resolution make it well-suited to study Neptune. Solar system - Planetary atmospheres Solar system 3000-01-01T00:00:00.000
457 2011.0.00084.S 0 The V4046 Sgr Disk: A Benchmark for Planetesimal Evolution_(Rev_0.8) We propose a 2-hour "compact" configuration observation of the CO 6-5 line and 700 GHz continuum emission from the unique, nearby (73 pc), and "old" (8-20 Myr) disk around V4046 Sgr. The proximity and age of this massive, gas-rich disk offer a rare opportunity to observe the subtle effects produced by the growth and migration of its solid contents with high sensitivity and spatial resolution. The proposed ALMA observations will be used in tandem with our SMA data (CO 2-1 and 230 GHz continuum) to make two key measurements: (1) use the resolved CO 6-5/2-1 line ratio to determine the gas temperature profile and effective size of the gas disk relative to the dust, a key indirect diagnostic of the radial variation in the gas-to-dust ratio that should be induced by the inward radial drift of solids; and (2) compare the continuum emission morphologies at 700 and 230 GHz to search for evidence of the particle size segregation expected in solid migration models. Although studying these effects is a relatively new topic enabled only now with the start of ALMA science operations, the size and spatial evolution of disk solids is perhaps the most fundamental aspect of the early stages of planet formation. The V4046 Sgr disk is an ideal proving ground for planning future observations of these effects, as well as for highlighting how ALMA data permit rapid, significant progress toward more sophisticated analyses of circumstellar disk evolution and the formation of planetary systems. Debris disks, Disks around low-mass stars Disks and planet formation 2014-02-28T21:15:00.000
458 2018.1.01644.S 5 Constraining the Mass of the Planet in the Gap Discovered in the TW Hya Disk We propose to observe the 13CO and C18O J=3-2 line emission towards TW Hya with high spatial resolution and high sensitivity in order to detect a gas gap in the disk. Our cycle 3 DDT multiple-band observations show multiple gap structure in dust continuum emission and an enhancement of dust spectral index at the gap at the disk radius of 22AU, which suggests the gap is likely to be caused by a planet. This proposal aims to constrain the mass of the planet by measuring the depth and width of the gas gap at 22AU. In order to derive the planet mass precisely, we need to know the properties of the gas gap, rather than the dust gap, since the distribution of dust is affected by dust filtration. At the 22 AU gap, the C18O line is optically thin and a good tracer of gas surface density distributions together with the optically thick 13CO line as a tracer of gas temperature at the gap. Our cycle 4 observations have been partially performed and show a hint of gas gap at 22AU. This proposal is to complete out cycle 4 observations. This will be a pioneering study of the formation environment of a planetary system, taking advantage of the TW Hya's proximity. Disks around low-mass stars Disks and planet formation 2021-01-30T17:11:39.000
459 2016.1.00980.S 60 After the Fall: Zooming In on the Molecular Fuel in Post-Starburst Galaxies Contemporary models of galaxy evolution require feedback to expel a substantial fraction of the gas and dust fueling stellar and black hole growth, driving galaxies into quiescence. Post-starburst galaxies are systems found precisely in this phase - shortly after star formation has been abruptly halted - but little is known about the dust and gas content of these systems. We have recently discovered surprisingly large reservoirs of dust and molecular gas in a sample of post-starbursts, and have mapped 4 quenched galaxies spanning a range of post-burst age with ALMA in CO2-1 at ~1.5kpc resolution. These maps reveal compact and disturbed gas kinematics along with potential outflows. To understand the fate of molecular fuel after quenching, we propose deep CO 2-1 maps zooming in on 4 post-starbursts previously mapped by ALMA. These galaxies span a wide range of post-burst ages, and all have well-measured molecular gas and dust masses together with other vital dust, neutral gas, and ionized gas tracers. With ALMA's remarkable sensitivity and resolution, we can directly target the 0.15"=~200pc scales of large GMCs to directly probe the kinematic and physical state of the gas. Starbursts, star formation, Merging and interacting galaxies Active galaxies 2018-01-06T16:32:00.000
460 2022.1.00338.L 174 The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) ExoKuiper belts are a ubiquitous component of planetary systems that provide a unique window into their outer regions (where only Jupiter-mass planets are currently detectable), constraining their architecture, formation and evolution. ALMA has revolutionized this field by characterizing in detail the structure of 6 belts, revealing radial and vertical substructures that hint at the presence of low mass planets, as well as unveiling their gas components. We propose ARKS to characterise 18 exoKuiper belts to understand the diversity and ubiquity of radial and vertical substructures and study their gas kinematics in a systematic way. We will systematically search our targets for signatures of planets with masses as low as Neptune's shaping the radial distribution, bodies as small as Pluto stirring the disc, and Saturn-mass planets distorting the gas rotation, all within the 30-300 au unexplored region in the planet mass and orbital radius space. Our program will provide a definitive characterisation of all exoKuiper belts bright enough to resolve radial and vertical substructures with ALMA, and our products will become a fundamental legacy to further studies of exoplanetary systems. Debris disks, Exo-planets Disks and planet formation 2024-01-18T14:50:06.000
461 2021.1.00800.S 5 The First Kinematic Mass Estimate of a z>6 Black Hole Current black hole mass estimates for some z>6 quasars yield impressively large masses, often exceeding 1 billion solar masses; challenging models of the early formation of supermassive black holes. However, these estimates are solely based on rest-frame UV/optical scaling relationships derived in the local Universe, which need not hold at high redshift. There is therefore a dire need to validate these scaling relationships at high redshift. This is exactly the aim of this proposal. Using 0.04" resolution imaging of the [CII] emission line, we aim to resolve the black hole sphere of influence for the z=6.8 quasar J0109-3047, which has a black hole mass of 1.5 x 10^9 Msun. The expected increased velocity dispersion within this central region of the galaxy will give an independent, kinematic measurement of the mass of the black hole. Previous observations have shown that not all quasars are suitable for these measurements due to the extreme high gas densities within their central region. J0109-3047 is the only quasar for which this measurement is possible within 10 hours of on-source observation time; providing the first kinematic mass measurement of a z>6 black hole. High-z Active Galactic Nuclei (AGN) Active galaxies 2022-11-10T19:31:29.000
462 2016.1.01015.S 42 The Extreme UV through ALMA's Eyes: a unique probe of the ionizing spectrum of OB Stars The extreme ultraviolet (EUV) of OB stars cannot be probed directly from the ground or from space; their EUV are thus very poorly constrained. Our theoretical work demonstrates that the mm/submm recombination lines of HI and HeII are excellent probes of the EUV: they have little dust absorption, they arise from H and He (thus independent of metallicity) and their fluxes depend linearly on number of EUV continuum photons. The He++ region (producing HeII emission) requires 54 ev photons, thus the EUV hardness is directly probed by the HeII/HI flux ratio. We propose observations of HI and HeII in compact OB star regions. These observations will open a new observing window on the EUV, getting down to a He+ line strength ~0.001 of HI. The measured hardness of the EUV spectra will provide critical input to starburst synthesis models. Main sequence stars Stars and stellar evolution 2018-05-25T05:58:53.000
463 2011.0.00612.S 0 An Off-Nuclear Starburst in the Luminous IR Galaxy IIZw96 v1.1 The infrared luminous merger IIZw096 contains an extremely compact off-nuclear starburst that is the source of more than 80% of the total infrared luminosity. IIZw096 is a rare example of a galaxy caught in the early merger stage of driving its vast reservoirs of molecular gas inward toward what will become the merger remnant and is reminiscent of the more famous merging galaxy NGC4038/9 (the Antennae) but an order of magnitude more luminous at log(LIR/Lsun) = 11.94. We propose to map the off-nuclear starburst on spatial scales of 0.25"-3.0" over the entire starburst region. Given the small spatial extent and the need for extremely high sensitivity and spatial resolution, we request extended and compact array observations in Band 9 to trace the molecular gas via CO J=6-5, HCO+ J=8-7 and HCN J=8-7, and to measure the 450um dust continuum all on scales of 200-300 pc. The resulting high spatial resolution maps will allow comparisons between the distribution of the bulk of the molecular gas (via CO J=6-5) and dust (at 450um), the location of higher density clumps (from HCO+ J=8-7 and HCN J=8-7), and structures seen in the near-infrared. The velocity will reveal possible infall or outflows of gas as well as pinpoint the dynamical center and how it relates to the density and temperature of the gas. Together the morphology and kinematics of the dense (cool) molecular gas that dominates the mass and fuels the star-formation will reveal the precise nature of the starburst and ultimate fate of the system. Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Galaxy evolution 2013-10-19T19:50:00.000
464 2015.1.00907.S 56 Smoking gun confirmation of dusty nuggets as progenitors of the red nuggets at z~2 The discovery of the "red nugget" population (massive, compact, quiescent galaxies) at z=2 indicates that early passive galaxies were remarkably compact compared to their present-day elliptical counterparts. Recent observations have identified a population of compact, star forming galaxies (so-called "dusty nuggets") that appear to be the direct progenitors of the red nugget galaxies. While several pieces of indirect evidence link these two populations, ALMA observations will provide the smoking gun confirmation that dusty nugget galaxies are the star forming progenitors of the first generation of red sequence galaxies. Therefore, we request 3.5 hours to obtain Band-7 luminosities, continuum and CO maps on 4 dusty nuggets to: (a) determine if their star-forming components are as compact as the stellar components of red nuggets, (b) verify a short quenching (gas depletion) timescales consistent with the rapid build up the red nugget population and (c) resolve their gas kinematics. Galaxy structure & evolution Galaxy evolution 2018-01-06T01:22:24.000
465 2018.A.00031.T 95 Exploring the dust, thermal gas, and new methanol masers in the third massive protostellar outburst: G358.931-0.030 The first identification of accretion outbursts in massive protostars happened in two separate regions within the past two years, profoundly impacting the field of massive star formation. Because both events were accompanied by maser flares, single-dish maser monitoring programs were reinvigorated. As a result, a third event was discovered on 14-Jan-2019 in a poorly-studied massive star-forming region, G358.931-0.030. Since then, the global maser community has made the astounding first discoveries of numerous torsionally-excited methanol maser lines from 6-360~GHz, all likely powered by the ongoing accretion outburst. Because this outburst has been caught in a much earlier stage, we have the best opportunity yet to explore and understand the underlying mechanism. Much like NGC6334I-MM1, the lack of a near-IR counterpart indicates a very deeply-embedded protostar. ALMA DDT observations are now critical to provide a clear picture of star formation in this protocluster by pinpointing the outbursting protostar with respect to the masers before they fade, and placing their kinematics into context of the dust and thermal gas structures that trace protostellar accretion and outflow. High-mass star formation ISM and star formation 2020-02-23T21:08:22.000
466 2015.1.00260.S 99 A survey for CO[5-4]emission in star forming galaxies at 1.1<z<1.7 We propose to detect CO[5-4] (and the 520um rest-frame continuum as a bonus) for 127 galaxies at 1.112 measured by Herschel, including similar numbers of main sequence and starburst galaxies. Thanks to our direct detection with IRAM PdBI of CO[5-4] in a small sample of comparable objects, and evidence of a linear LIR to LCO[5-4] relation, we can reliably estimate required integration times that are of order of 1 minute per galaxy, enough also for continuum detections. For all these targets we will have a measurement of high-J CO[5-4] luminosity, LIR, Mdust and Mgas (from continuum) and of U=LIR/Mdust, the hardness of the radiation field. We will be able to perform an unprecedented investigation into the nature of star formation inside high-redshift galaxies, statistically confirm the supposed linear relation between LIR and L'CO[5-4] and measure its scatter and systematics for different galaxy types, and explore the correlation between CO excitation and star formation efficiency. With 6.2h of ALMA observing time in Band6 we will obtain the first statistical sample of CO detections in the z~1.4 Universe. Starburst galaxies, Galaxy structure & evolution Active galaxies 2017-04-27T20:57:02.000
467 2013.1.00576.S 10 Observations of the [CII] Emission Line in Hot-Dust Obscured Galaxies The WISE mission has recently identified a rare population of high-redshift, hyper-luminous infrared galaxies, all with bolometric luminosities above 10^13 L_Sun, and many exceeding 10^14 L_Sun. Characterized by their extremely red mid-IR colors and very hot dust temperatures, these hot, dust obscured galaxies (Hot DOGs) likely probe a key stage in the galaxy evolution paradigm. The bulk of the IR emission in Hot DOGs is powered by AGN activity, outshining possible fainter cold emission associated to star formation. The only way to study the ISM properties of the host galaxy in these objects, as well as the effects of the AGN on it, are through kpc-scale imaging of the dust and gas at sub-mm wavelengths. We propose here to use ALMA to obtain deep, high-resolution observations of the 157.7um [CII] emission line and of the FIR continuum in a small sample of carefully selected Hot DOGs to constrain the physical properties of the their dust and gas components and gain insights into their star-formation properties. Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Active galaxies 2017-11-08T00:00:00.000
468 2012.1.00940.S 4 Nature of a Flat Face, Energetic High-Velocity Compact CLoud in the Galactic Center High-velocity compact cloud (HVCC) is a peculiar population of molecular cloud found in the central molecular zone of our Galaxy with the NRO 45m telescope CO J=1-0 survey. They have compact size, extremely large velocity width, and enormous kinetic energy ranging from 1E49 to 1E52 ergs, while their driving sources are still unidentified. CO -0.40-0.22 is one of energetic HVCC (Ekin ~ 1E51 erg) with a featureless appearance. Our observations with ASTE have revealed that it has intense CO J=2-1 and HCN J=3-2 emission suggestive of high density and moderate temperature. We propose to make 7-point mosaic observations of CO -0.40-0.22 with ALMA. HCN J=3-2 and CO J=2-1 lines will be observed to obtain detailed spatial-velocity information to diagnose its kinematics: (1) rotation around a dark mass, (2) expanding shells/bubbles, or (3) supersonic collision. Cases (1) and (2) are indicative of an embedded, aged super star cluster (SSC), which could be a womb of intermediate mass black hole. Detection of rotating motion may enable us to calculate the enclosed mass and thereby to examine the existence of an IMBH within CO -0.40-0.22. Early-type galaxies Galaxy evolution 2016-03-16T13:19:50.000
469 2022.1.00134.S 0 Band 6 ACA Photometric survey of double-belts debris disks Debris disks are a common feature of mature planetary systems, and SED modeling has shown that double-belt configurations similar to the Solar System's asteroid and Kuiper belt are common as well. While it is important to understand the architecture of these systems, degeneracy between radial structure and grain size distribution and composition plagues SED modeling efforts. However, at mm wavelengths, the emission is largely dominated by the coldest of the two belts, and its spectral slope is mostly sensitive to its dust grains' size. Therefore, we propose here to observe a sample of double belt debris disks discovered through SED modeling of Herschel data, making use of the ACA only. By obtaining the slope of the cold belt SED at mm wavelengths, and in conjunction with the Herschel measurements, we will be able to determine its grain size distribution, refine architectural constraints obtained through SED modeling by disentangling the cold belt SED from that of the warm belt, and determine disk masses with more accuracy. Debris disks Disks and planet formation 2024-08-22T18:34:37.000
470 2013.1.01329.S 21 Feeding and Feedback in the central region of NGC 613 We propose to observe the central region of the nearby galaxy NGC 613 (17.5 Mpc) in Band 3 (HCO+ and HCN 1-0, CS 2-1, SiO 2-1 and 100 GHz continuum) and in Band 7 (HCO+ and HCN 4-3, CS 7-6 and CO 3-2) with 0.25” (21 pc) and 0.5” (42 pc) resolution, respectively. We detected hot gas in the central region. ALMA observations resolve the circum-nuclear disk, nuclear ring and jet/outflow. It observationally reveals following important topics of fueling process of AGN. 1. We reveal inflow gas from nuclear ring to center by kinematic analysis of CO 3-2 assuming circular rotation of the nuclear ring. 2. We estimate kinematic energy of the outflow gas using the identified direction of the outflow from the nucleus. 3. We identify heating source (X-ray, shock) of the hot gas in the circum-nuclear disk using distribution of shocked gas traced by SiO and physical condition of the gas derived from intensity ratio of HCN, HCO+, CS and CO. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 3000-01-01T00:00:00.000
471 2017.1.00040.S 361 Replenishing Molecular Gas Near the Supermassive Black Hole SgrA* The detection of the 2-pc circumnuclear disk (CND) immediately around the Milky Way supermassive black hole (SMBH), SgrA*, provides an unique laboratory to study SMBH accretion at sub-pc scales. Theoretical model predicts that the CND was formed through the tidal disruption of nearby molecular clouds. Indeed, our previous CS(2-1) and HCN(4-3) maps with ALMA and SMA revealed that the streamers surrounding the CND are the tidal debris captured from the nearby clouds. The streamers show inflow motion and finally ends up co-rotating with the CND. We also found that the key elements - compact cores - inside the streamers may be the infall seeds or the sites of star formation. We propose to obtain a 0.5"-1" resolution map with the 5 CS lines to resolve the compact cores in the streamers and the CND. With the unprecedented ALMA maps, we will, (1) Measure the CND and streamers mass ratios to evaluate the importance of the inflow and SMBH feeding. (2) Measure the densities and sizes of the compact cores to derive the "surviving fraction" as a function of distance to SgrA*. (3) Fit the inflow kinematics to constrain theoretical models for their dynamics and fates. Galactic centres/nuclei Active galaxies 2019-07-16T00:00:00.000
472 2017.1.01565.S 215 A comprehensive inventory of nitrogen isotopic ratios in a nascent solar system Understanding the origin and evolution of the solar system's organic material is a central question in astrochemistry. The nitrogen isotopic ratio, 14N/15N, is one of our main tools to trace the history of the organics. Because the highest 15N-enrichments in the solar system exist in the most pristine organic matter in meteorites, an inheritance from the earliest stages of solar system formation is likely. However, measurements of the 14N/15N ratio in star-forming regions so far present a puzzling picture, with 15N being enriched in certain molecular tracers but not in others. We propose to precisely measure the 14N/15N ratio from a comprehensive set of tracers in a young solar system analog, using for the first time not only simple molecules, but also complex organics. The proposed observations will provide us with a consistent set of spatially resolved 14N/15N measurements to investigate differences between molecules deriving from the atomic versus molecular nitrogen reservoirs. With the complex organics, we will also take a first step towards understanding how the 15N-enrichments in the gas are eventually incorporated into the organic matter of meteorites and cometary ices. Low-mass star formation, Astrochemistry ISM and star formation 2019-01-24T08:12:37.000
473 2015.1.00820.S 136 Dark Matter in Dwarf Galaxies The dwarf galaxy dark matter survey described in this proposal will measure the radial distribution of dark matter (DM) in a sample of 13 DM dominated dwarf galaxies. The goal of the project is to determine the functional form of the DM distribution on scales of a hundred parsecs, and the degree to which the DM varies from galaxy to galaxy as a test of the Lambda CDM model on small scales. The scope of the project will permit for the first time the possibility of correlating the DM properites with other galaxy properties such as mass, gas density, star formation history, etc. We will measure the DM distribution by combining 2-D velocity fields of the galaxies in CO, which provides the least biased and coldest kinematic tracer at small radii together with Palomar Halpha integral field spectroscopy to extend the measurements to larger radii. Together with near-infrared imaging to secure the stellar mass distribution, we will remove the baryonic contribution to the observed rotation and model the kinematics. This data set will be the largest homogenious survey of the DM in the inner regions of galaxies undertaken to date. Surveys of galaxies Galaxy evolution 2017-02-19T16:28:22.000
474 2016.1.00193.S 183 The substructure of molecular clouds in the LMC We propose to map a sample of four molecular clouds, each roughly 40 pc in diameter, distributed across the LMC and exhibiting a range of star formation activity. With ALMA we will mosaic the full extent of each cloud in the J=1-0 transitions of CO and 13CO. Our survey is distinct from previous efforts in mapping a wide area of each cloud, not just the CO peak position or star formation `hot spots', and observing both optically thin and thick species to derive column densities and excitation temperatures. Our immediate objective is to quantify the statistics of density and velocity fluctuations that can be directly compared among our cloud sample, with Galactic counterparts, and with numerical simulations. The dependence of these statistics on location within a cloud, location within the galaxy, and star formation activity will provide much-needed empirical benchmarks for theories of cloud formation, evolution, and dynamical stability. Low-mass star formation ISM and star formation 2018-03-15T23:08:30.000
475 2022.1.00303.S 0 Testing the origin of warm carbon-chain chemistry in Perseus protostars Carbon-chain molecules (CCMs) are thought to form efficiently in prestellar stage and quickly disappear in protostellar stage due to the rapid conversion of C to CO. However, detection of CCMs in embedded protostars challenges this paradigm. The warm carbon-chain chemistry (WCCC), initiated by sublimation of CH4, was proposed to explain the observed CCMs in protostars. While single-dish surveys find that CCMs almost ubiquitously appear in protostellar cores, whether active WCCC leads to the existence of these CCMs remains unclear. To test the CH4 origin of CCMs, we propose a survey of key CCMs, C2H and c-C3H2, toward an unbias sample of protostars in the Perseus molecular cloud. We will map the emission of CCMs at a few thousands au scale, where the WCCC is expected to be active, and further constrain their excitation. In this survey, we will directly confirm the existence of warm and concentrated CCMs, indicative of active WCCC. Thus, the origin of CCMs will be unambiguously determined. Low-mass star formation, Astrochemistry ISM and star formation 2024-10-04T07:35:38.000
476 2013.1.01147.S 18 Planet formation at a critical age: debris disks with gas in the 8 to 20 Myr range The η Chamaeleontis association and the β Pictoris moving group of young low-luminosity nearby stars, represents an ideal laboratory to study planet formation at a critical age range: between 8 and 20 Myr. This stage is regarded as post protoplanetary/primordial disk, hence they are assumed to be young debris disks. We propose to conduct ALMA band 6 observations of 10 systems with clear excesses of emission at long wavelengths, evidencing the presence of circumstellar disks. Some of these systems may also contain disks with inner cavities (based on SED studies). The aims of this proposal concern mainly the determination of disk masses, sizes and detect primordial gas. Recent studies have shown evidence that some of these ’debris’ disks might still contain appreciable quantities of gas, challenging the idea that most disks lose all their gas at a rather early age (2-10 Myr). Debris disks Disks and planet formation 2016-11-26T12:12:39.000
477 2022.1.00863.S 303 Confirming significant dust-obscured star formation at z>3 in a new ultra-deep radio survey Tracing the star formation history of the universe at redshifts z>2 is significantly complicated by the presence of likely substantial yet uncertain dust attenuation. Recently, a new ultra-deep radio survey has been carried out in the premier COSMOS field with the VLA (COSMOS-XS), putting state-of-the-art constraints on the dust-unbiased star formation rate density (SFRD). However, `optically dark` galaxies could not be included due to their unknown redshifts. Using a super-deblending technique on the wealth of FIR data, we have now derived FIR-based photo-zs for the sources, including 10 S_1.1>3.5 mJy sources with estimated redshifts z=3.4-7.5 and SFRs=550-1100 Msol/yr based on current estimates, comprising a full ~50% of the total SFR of the optically dark population. Here we propose ALMA 3mm spectral scans of these 10 sources, which (in combination with the super-deblended photometry) has proven 100% successful in confirming spectroscopic redshifts. This will allow us to place important constraints on the relative contribution of such optically dark sources to the SFRD and determine the importance of dust-obscured star formation in general at the highest (z>3) redshifts. Sub-mm Galaxies (SMG) Galaxy evolution 2024-02-23T00:07:55.000
478 2016.1.01184.S 57 Accurate gas-to-dust ratios with [CI] at z~1 Research in galaxy evolution aims to understand the cosmic industry of converting gas into stars. We have abundant photometric data to measure star formation rates and stellar mass evolution within galaxies and the Universe as a whole, but our understanding of gas mass evolution in the Universe must be improved to complete the picture and validate models. Almost all high-redshift gas measurements to date rely on CO as a tracer, but this is plagued by systematic uncertainties due to optically thick emission and poorly constrained dependences on gas density, distribution and metallicity. Recently some attention has been given to using dust as a gas tracer by assuming a constant gas/dust ratio, which shows promise for large samples but still requires accurate calibration on a direct gas tracer at high redshift. The [CI] line offers an opportunity to overcome much of the systematic uncertainty, yet observers have been slow to capitalise on this. We propose a survey of [CI] in a representative sample of star-forming galaxies at z~1 to measure accurate molecular gas and dust masses and provide a calibration that will be applicable to a wide variety of high-z star-forming galaxies. Galaxy structure & evolution Galaxy evolution 2018-03-29T17:03:51.000
479 2021.1.00960.S 0 Detecting extended [CI] emission in the 4C23.56 protocluster at z=2.5 We propose deep Band 4 ACA observations of [CI](^3P_1-^3P_0) line toward a protocluster at z=2.5, 4C23.56, one of the well-studied protoclusters at z>2. We aim for confirming the existence and the distribution of extended cold and dense components in the circum-galactic medium (CGM), which is inferred from the currently available data sets of CO and [CI] lines that are detected at high resolution (<1"), in the protocluster. The proposed program will place a constraint on the `missing baryon' and in particular the fraction of the cold and dense gas in the CGM for the protocluster. This will eventually help us to understand the stellar growth of massive galaxies in the peak epoch of galaxy and cluster formation. High-z Active Galactic Nuclei (AGN), Galaxy Clusters Active galaxies 2025-06-04T10:27:15.000
480 2019.1.01517.S 104 Gas around MS stars: A common exocometary origin for hot and cold gas Non-negligible amount of gas has been found around main sequence AF-type debris disc stars by means of emission lines of CO, CI, CII, and OI. The origin of this cold gas located in the outskirts of < 20 debris disc systems is still under debate, but it is mainly attributed to collisions or evaporation of icy bodies such as planetesimals or exocomets. The report by our group of the presence of hot gas attributed to exocomet evaporation, and detected in optical wavelengths in the cold gas bearing debris disc systems with edge-on orientations points towards a possible common origin, and therefore a correlation. The presence of a scattering body (a.k.a. planet) provides a simple way of relating both gas components. We propose observations of CO (2-1) line of a sample of 8 stars with optical cometary absorption features to confirm a potential link between the inner exocomets and outer icy-planetesimals. Debris disks Disks and planet formation 2021-03-15T01:55:21.000
481 2021.1.01313.S 55 AGN in the SPT2349 protocluster at z=4.31 We propose a search for AGN associated to galaxies in the most massive, highest SFR density protocluster known, SPT2349-59 at z=4.31. The AGN are likley to be dusty and while not unique identifiers sub-mm lines efficiently povide access to the entire AGN census. We will use deep ALMA observations of the protocluster in CO(14-13), CO(11-10) and CO(7-6) to provide high-J through mid-J CO lines for comprahensive SLED analysis of composite PDR+XDR models in combination with CO (4-3) and CO (2-1) data already avalible. The SPT2349 protocluster shows at least 12 sources with weak C+/FIR ratios, a possible signature of AGN-dominated emission, and many AGN are likely in the protocluster system. We will address what powers the bright ALMA protocluster sources, whether SMBH's are triggered by dense environments, and whether mergers trigger AGN and SF activity. Sub-mm Galaxies (SMG) Galaxy evolution 2023-09-19T09:36:39.000
482 2019.1.01034.S 45 Resolved Molecular Gas in z~1 Star Forming Clumps We propose to use the ALMA 12-m array to observe molecular gas and the dust continuum in resolved star forming clumps in 4, z~1 main sequence galaxies previously observed with the Keck/OSIRIS IFS. Studies of the resolved structure and kinematics of high-redshift (1 Starbursts, star formation, Surveys of galaxies Active galaxies 2021-03-10T19:15:35.000
483 2011.0.00064.S 0 Clustered Massive Galaxy Formation around a z=5.3 Submillimeter Galaxy Cosmological simulations suggest that massive galaxies at present day form in the densest regions in the early universe, predicting the existence of massive protoclusters of intensely star-forming galaxies as their progenitors at high redshift. We have recently identified such a unique region within 1.1 billion years of the Big Bang, hosting an extreme starburst galaxy (the most distant submillimeter galaxy (SMG) identified to date, forming stars at 1800Msun/yr), and at least twelve normal star-forming galaxies (LBGs, the bulk are spectroscopically confirmed, and have 1-2 orders of magnitude lower SFRs than SMGs), within a narrow redshift interval of only dz=0.002. This most distant protocluster region known is a "smoking gun" for early massive galaxy formation through hierarchical buildup, giving key importance to understanding the physical properties of its member galaxies and the three-dimensional structure of the region in great detail. This proposal aims to add an essential missing piece to our comprehensive dataset on this proto-cluster by mapping out its core region in [CII] and rest-frame far-infrared continuum emission, using the ALMA early science array. This will critically constrain the neutral interstellar medium (ISM) content, excitation, distribution and kinematics of the central six LBGs (which, including the SMG, are situated within a single ALMA primary beam FWHM), constituting the fuel for their star formation, and dust-obscured star formation rates. This will also yield unprecedented constraints on the star formation law at z=5.3, and will enable the first direct ISM studies of LBGs at z>3. The [CII] measurements will give an order of magnitude more precise redshifts, substantially constraining the 3D structure of the protocluster. Starburst galaxies, Galaxy groups and clusters Active galaxies 2014-02-20T16:50:00.000
484 2017.1.01444.S 28 Studying the effects of variable UV heating on the outer disk Here we propose to use ALMA to undertake the first variability study of UV sensitive lines in the millimeter in an object that is known to have substantial UV variability: GM Aur. We propose for a total of 1.5 hrs to observe the CN and HCN lines three times. If we detect variability, this would be the first observed link between UV emission and the heating of gas in the outer disk. This will complement our previous HST and near-infrared studies of GM Aur, where we studied the star-inner disk connection, by expanding this to the outer disk. Low-mass star formation, Astrochemistry ISM and star formation 2019-08-24T13:15:32.000
485 2017.1.00789.S 60 SN1987A: an evolving treasure trove of physics SN 1987A provides an exceptional opportunity to observe the creation of a supernova remnant. ALMA provides unique information by probing both the cold molecular gas in the core of the ejecta through the emission of CO and SiO, and the synchrotron emission arising from the shocks and possibly a plerion. The high spatial and spectral resolution of ALMA provide a spectacular 3D view into the structures that were frozen into the ejecta at the time of the explosion. Therefore ALMA provides us with observations that directly test the energetics of the explosion, progenitor structure, and macroscopic mixing. We propose to follow up our cycle 3 observations to observe the evolution of the ejecta as the X-rays from the reverse shock propagate into the supernova. Over the 1000 day interval since our previous observations, ALMA can resolve the expansion of the ejecta at >2000km/s. Over the same time inverval the X-ray penetration of the ejecta has increased significantly, and the radioactive 44Ti heating has decreased. We shall also observe the ongoing destruction of the ring and seek evidence for a compact remnant. Evolved stars - Chemistry Stars and stellar evolution 2018-12-22T19:59:06.000
486 2023.1.00432.S 0 Sub-kpc mapping of dense gas in high-z star-forming galaxies Dense gas is the key to star formation. However, very little is known about the dense-gas content of galaxies at z>1, as the HCN, HCO+, and HNC lines which trace the dense gas are often >1 dex fainter than the CO or [CII] emission. Recent spatially unresolved observations indicate that despite their enormous star-forming rates, high-z galaxies contain relatively little dense gas but convert it into stars efficiently. Still, to properly quantify the star-forming efficiencies in them, we need to map their dense gas on sub-galactic scales. We request 36 hours of 0.3" imaging of the HCN, HCO+, HNC(4-3), and CO(3-2) emission on ~500-pc scales in three strongly lensed z~3 galaxies - an on-going merger, a post-coalescence merger, and an isolated disk. We will: (1) map the star formation, molecular and dense gas across 10+ resolution elements in each galaxy; (2) use the HCN/HCO+/HNC/CO ratios to characterise the physical conditions of the dense-gas phase; (3) pinpoint potential compact obscured nuclei. Together, this project will provide the first high-resolution view of these key ingredients of star formation in high-z, intensely star-forming galaxies. Starburst galaxies, Sub-mm Galaxies (SMG) Active galaxies 2024-11-27T22:26:28.000
487 2013.A.00023.S 6 Follow up of possible Galactic Supernova in the disk A search of the VVV 1st Data Release led to the discovery of WIT-01, a very high amplitude variable with unusual colors from amongst 50 million sources (Minniti et al. 2012, ATel 4041). WIT-01 is very red: H−Ks=5.2 mag, and invisible in the Z, Y and J passbands. The very rapid decline in flux by >8 magnitudes plus the very red colors are unprecedented, and inconsistent with known examples of variable stars. Therefore, we postulated that this object would have to be the prototype of a new sub-class of PMS variable, or alternatively, a highly extincted supernova in the Milky Way (Av~100 mag), detected at some time after maximum light. We submitted an ALMA proposal in 2012 to test these possibilities, and now that the observations are finally concluded, we detect a new source in the field. There was no detection in band 3 in 2013 and 2014, but there is now in August 2015 a new source very close to the hypothetical SN and with the right predicted flux. However, there are still some doubts about the position, and we hereby request 3.2 hours of ALMA time in total to confirm this detection before announcing this exciting discovery. Supernovae (SN) ejecta Stars and stellar evolution 2016-05-10T00:00:00.000
488 2017.1.01045.S 18 Resolving molecular gas to ~500 pc in a unique star forming disk galaxy at z~2 For the first time ever, we will resolve molecular gas in a 'typical' star forming disk galaxy at z>2 down to the scale of ~500 pc. The target, BX610, is a massive disk galaxy with large gas reserves which, unlike many galaxies studied at high redshift, is undergoing modest quiescent star formation, likely through cold mode accretion. This galaxy therefore represents an under-studied, but cosmologically important population in the early universe. We have already carried out observations on larger spatial scales to determine bulk molecular and atomic gas properties with CO(7-6), CO(4-3), [CI] (2-1), and [CI] (1-0), and now we intend to probe CO(4-3) emission to unprecedented resolutions. These observations enable an unprecedented view of the obscured star formation that is hidden to optical/UV imaging. We will trace out the bulk of the molecular gas fueling star formation on a fine enough scale to resolve morphological traits and provide a view akin to single dish surveys in the local universe. Furthermore, this will provide a test of the star formation rate surface density scaling law in a never-before-investigated regime. Damped Lyman Alpha (DLA) systems Cosmology 2019-03-26T14:31:10.000
489 2016.1.00017.S 5 First Mapping of the B-fields in the Protostellar Jets Near the Launching Point Protostellar jets are believed to be the key to removing excess angular momenta from accretion disks, allowing material to fall onto the protostars during the star formation. In current jet launching models, magnetic fields (B-fields) are required to launch and collimate the jets, and thus expected to be helical in the jets. Our previous attempt to map the B-fields in the brightest jet in SiO with the Submillimeter Array has shown a tentative detection of polarization in the outer part that could be due to helical B-fields. With ALMA, we propose to zoom in and map the B-fields in the inner part of the jet near the launching point (within ~ 560 AU of the source) in SiO at higher angular resolution with unprecedented signal to noise ratio. By measuring the pitch angle and the strength of the B-fields, we aim to determine how efficient the B-fields can accelerate and collimate the jets, setting the first constraint on the role of the B-fields in the jet launching models. Outflows, jets and ionized winds, Low-mass star formation ISM and star formation 2018-11-07T15:06:13.000
490 2022.1.00236.S 0 Exploring the sulphur content of Class I protostars Sulphur-bearing molecules may have played an important role in the origins of life on Earth, however, the sulphur chemistry is poorly understood in the process of low-mass star and planet formation. Dense cores are depleted in S-bearing species, while deeply embedded protostars and cometary samples show different abundances of S-molecules. We lack information about the evolution of the sulphur chemistry along the different stages of star and planet formation and, in particular, about the sulphur content of Class I sources and its potential contribution to late accretion and planet formation. We propose to survey a sample of 30 Class I sources located in three different star-forming regions. The ACA configuration and a single Band 7 spectral correlator setup will be used to observe the most simple S-bearing molecules, achieving an angular resolution of ~3.5". Our goal is to investigate whether the most common and simple S-bearing species are present in Class I sources and, if so, to determine how bright they are and compare abundance ratios with other stages of star formation. This survey will contribute considerably to our knowledge of the sulphur content in young protostars. Low-mass star formation ISM and star formation 2024-08-09T17:12:58.000
491 2015.1.01047.S 16 Resolving the HCN Enhanced Nuclei in Nearby Seyferts: HCN Masers or Dense Molecular Outflows? We aim to image the HCN(1-0) distribution and kinematics, together with the HCO+(1-0) and HNC(1-0) lines, toward the HCN enhanced nuclei of nearby Seyfert galaxies, NGC 1097, NGC 3227, and NGC 5033. These galaxies show strongly enhanced HCN(1-0) emission toward their Seyfert nuclei, suggesting the effect of AGN activities to the surrounding molecular gas. Indeed, one of the HCN enhanced nucleus galaxy M51 shows AGN-driven molecular outflows and a HCN maser toward the nucleus, suggesting that other galaxies also have similar phenomena in their nuclei. We look for the evidences of AGN-driven outflows, HCN masers, and/or AGN radiation effect using HCN(1-0), HCO+(1-0), and HNC(1-0) lines, which can be observed simultaneously. With these observations, we will study what drives the molecular outflows from AGNs (jet vs radiation), whether the nuclear disk exists or not, and/or what is the effect of strong AGN radiation to the surrounding molecular gas. Since there are very few studies of spatially and kinematically resolved circumnuclear molecular gas, this study will provide a solid understanding of AGN feedback mechanism. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 2018-04-11T08:46:12.000
492 2017.1.00621.S 111 Search for host galaxies of metal absorption systems near the Epoch of Reionization Metal absorption systems seen in high-z quasar spectra are a useful tool to study the ionization state and chemical enrichment of the inter/circumgalactic media and processes occurring within young galaxies near the epoch of reionization. However there are currently no observational identifications of galaxies associated with any metal absorption systems at z>4.5. We thus propose to obtain [CII]158um images for the fields of 20" (~100 pkpc) in radius centred on three quasars at z>6 to identify galaxies associated to metal absorption lines at 4.8 Galaxy structure & evolution Galaxy evolution 2019-10-08T20:29:19.000
493 2021.1.00105.S 24 The parsec scale view of the starburst ISM through molecular diagnostics Extreme activities in starburst galaxies have a direct impact on their molecular interstellar medium (ISM). The effects on the ISM are most prominent in the vicinity of young stellar clusters on parsec-scales, dominated by feedback in the form of heating and outflows. The starburst galaxy NGC 253, thanks to its proximity and brightness, allows the most detailed ALMA studies of such starburst ISM properties. Sub/millimeter molecular lines are very powerful to probe the dust-obscured starburst and young clusters. We started in Cycle 6, and propose here to complete, a multi-line, multi-species survey in Bands 6 & 7 at ~0.2" resolution in the central 15" of NGC 253. Using a variety of molecular diagnostics, we will study the molecular cloud physical properties, the chemical composition caused by various heating sources, extreme excitation conditions, and cluster-scale outflows. Our study will efficiently reveal the highly excited physical conditions and signatures of feedback in the nearest starburst galaxy NGC 253. Starbursts, star formation, Galaxy chemistry Active galaxies 2023-01-17T01:43:33.000
494 2022.1.01753.S 0 First direct imaging of a dwarf planet's ring system The dwarf planets represent a distinct class in the transneptunian population characterised by high densities, satellite systems, and a large variety of volatiles leading to complex surface chemistry. In this proposal we request ALMA band-7 observations to detect the thermal emission of the ring around the dwarf planet Haumea by direct imaging. The ring was recently discovered from occultation observations, the first one around a trans-Neptunian dwarf planet. Characterisation of the properties of the ring material will allow us to deduce whether it originates from collisional ejection or satellite disruption, and help to understand if ring systems can refresh ices on the surface of the main body, thereby explaining the high albedo of large trans-Neptunian objects. We will spatially resolve Haumea itself and determine its dimensions, directly imaging the triaxially-shaped, elongated dwarf planet at different rotational phases. We will be able to detect the spatially resolved thermal emission of the satellites, Hi'iaka and Namaka, crucial for the correct interpretation of system-integrated thermal emission measurements. Currently these goals can only be achieved by ALMA. Solar system - Trans-Neptunian Objects (TNOs) Solar system 2025-02-27T17:08:54.000
495 2019.A.00041.T 12 GRB 210905A at z = 6.318: Tracking the Farthest Cosmic Explosion Seen by ALMA This is an urgent ToO proposal for ALMA follow-up of the recent z=6.318 gamma-ray burst GRB 210905A. We have detected the mm and cm afterglow of this rare (once in 7 years) high-redshift (z>6) GRB with ALMA and ATCA, and expect it to be detectable only for another ~ 10 days. GRB 210905A is only the second high-z GRB ever with a mm afterglow, and the first high-z GRB detected with ALMA. Being associated with the deaths of massive stars, GRBs are excellent probes of star formation in the high-redshift Universe. Radio/mm observations of GRB afterglows are essential for quantifying the energy release, measuring the circumburst density, and constraining ejecta collimation. In turn, these quantities inform our understanding of processes ranging from stellar feedback to the origin of cosmic magnetic fields. However, high-z GRBs are extremely rare, and radio/mm detections are rarer still: 7 z>6 events are known, 4 of which have been detected in the cm-band and 1 in the mm-band. We request continued ALMA follow-up at ~ 7d & 15d after the burst. We will support these ALMA data with approved ATCA observations, extensive near-IR follow-up (VISTA), and X-ray monitoring (Swift, Chandra). Gamma Ray Bursts (GRB) Cosmology 2022-04-19T16:52:20.000
496 2017.1.00561.S 21 The Fomalhaut C Debris Disk: Key to the famous eccentric ring around A? The A-type star Fomalhaut is the primary component of a compelling and well studied extra-Solar stellar and planetary system; host to an eccentric planet (Fom b) and two distant low-mass companions (Fom B & C). Fom A hosts a spectacular eccentric debris ring. Our discovery of an unresolved disk around Fom C with Herschel prompted us to propose a "unified" stellar capture scenario that explains the origin of the wide triple star system and the eccentricity of the debris ring around Fom A, without invoking unseen planets. A key prediction of this scenario is that the debris disk around Fom C should be asymmetric and warped. We have obtained an HST dust-scattered light image of the Fom C disk that indeed shows a strong asymmetry, so supports our stellar capture scenario. The HST image suffers from high-contrast imaging artifacts and is only sensitive to small dust, issues which are avoided by ALMA imaging. We propose to image the Fom C disk structure with 3.2h of ALMA band 7 time to shed light on the origin of the Fomalhaut system, with wider application to the origin of wide stellar systems, whose origins are rarely tested. Debris disks, Disks around low-mass stars Disks and planet formation 2019-06-27T16:12:24.000
497 2016.1.01543.S 12 The Chlorinity and Chemical Composition of Europa's Subsurface Ocean Europa, an icy world orbiting Jupiter, is one of the most promising places for harboring life in the outer solar system. A global subsurface ocean was inferred to exist inside Europa from the diversity of surface geological features and the magnetic field measurements made by the Galileo spacecraft. In addition, detections of the atomic O and H emission by HST also suggested water vapors outgassing from Europas south polar region, similar to Enceladus plume activities. As the first step in understanding the potential of Europa being an abode for life, we propose to use ALMA to study the chlorinity and chemical composition of Europa's subsurface ocean, targeting the molecular species of NaCl, KCl and H2O in the atmosphere. Our proposed work will provide crucial information of Europa's outgassing events, the sources of Europas atmospheric species and their associated radiolytic effects (irradiated vs. prior-to-irradiated) as they can provide better constraints in the ocean chemistry models such as the salinity and the oxidation state. It will also contribute to future space missions, such as NASAs next flagship mission to Europa and ESA's JUICE mission. Solar system - Planetary atmospheres, Solar system - Planetary surfaces Solar system 2018-06-27T03:54:35.000
498 2011.0.00005.E 0 HL Tau Band 9 B2B ALMA engineering data release. 2018-07-10T12:50:54.000
499 2019.2.00120.S 2079 The Nearby Evolved Stars Survey: quantifying the gas and dust return to the Galactic interstellar medium Outflows of asymptotic giant branch and red supergiant stars drive local galactic chemical evolution. The Nearby Evolved Stars Survey (NESS) is a global project targeting a volume-limited sample of evolved stars within 2 kpc to constrain the physics driving mass loss. NESS includes ongoing JCMT (515 hr) and APEX (56 hr) surveys to observe CO(2-1), CO(3-2) and dust continuum from ~500 sources, and at the Nobeyama observatory (190 hr) for CO(1-0). We propose 12CO and 13CO(2-1) and (3-2) observations of the 280 NESS sources visible to the ACA that do not have archival data (total sample 301 sources). Combining the high resolution and large field-of-view of the ACA with data from the JCMT and APEX, we will thoroughly probe their inner shells, revealing the mass-loss history, geometry and the 12C/13C and dust-to-gas ratios. The large, volume-limited sample will robustly constrain the onset of mass-loss variations and asymmetry. All NESS data, including reduced data, catalogues, codes and model results will be publicly available. The NESS database is poised to become the authoritative source for evolved-star studies in the next decade, and the proposed ACA data will be a vital addition. Asymptotic Giant Branch (AGB) stars Stars and stellar evolution 2022-08-05T10:48:13.000
500 2015.1.01177.S 7 Twins at heart? The centre of M83 as a Milky Way analogue Detailed studies of the inner few 100 pc of the Millky Way are revolutionising our understanding of SF in extreme environments and feeding/feedback cycles in galactic nuclei. However, future developments are limited by the fact that we lie in the disc of our Galaxy, making it difficult to unambiguously determine the 3D geometry of gas and stars, and that the Galactic centre only provides a single snapshot of an evolutionary cycle. We seek to exploit M83's remarkable similarity with the Milky Way to overcome these limitations. ALMA observations will uniquely allow us to derive the density and pressure evolution of gas falling into the nucleus of M83 and determine (i) the dominant physical mechanisms regulating the mass flows and energy cycles down to the sizescales of individual clouds, and (ii) whether the star-forming clouds and stellar clusters follow an evolutionary time-sequence, which has been hypothesised to result from a tidal compression that triggers collapse. Starbursts, star formation, Galactic centres/nuclei Active galaxies 2017-11-07T19:19:06.000
501 2013.1.01241.S 5 Detecting [CII] in two strongly lensed z~6 star-forming galaxies We propose to conduct deep ALMA observation of two z∼6 sub-L∗ star-forming galaxies to detect their [CII] emission line and derive from the line flux their star formation activity. These two Lyman-break galaxies are unique multiple image systems found in the massive cluster lenses Abell 383 and MS0451-03 at redshift 6.027 and 6.703 respectively. Their lensing magnification is ~11 and 100 respectively thus allowing to probe the properties of "normal" low luminosity galaxies at early times in the Universe. The proposed observation will lead to a secure [CII] detection. However, would we not detect [CII] the upper limit we can derived will have strong consequences on our understanding of star formation in the early Universe advocating for unexpected strong evolution in the galaxy formation models. Lyman Break Galaxies (LBG), Gravitational lenses Galaxy evolution 2016-03-20T13:14:16.000
502 2015.1.01512.S 43 Has Planet Formation Already Begun in the Class I Protostellar Phase? Recent ALMA observations of the early Class II protostar HL Tau revealed gap structures indicative of newly-forming planets. The observations represent the earliest direct detection of planet formation, suggesting that planets form during the first million years of star formation. These observations showed that planets form before some theoretical predictions, which begs the simple question: "When exactly do planets start to form?" While it is known that planets should start their formation in a Keplerian disk, we do not know if they start forming at times significantly younger than HL Tau. To further constrain whether gap structure appears at an early stage, i.e., the Class I stage, we propose for high angular resolution (0.035" = 4.4 AU) toward the Keplerian disk IRS 63 located in Ophiuchus. This source is one of the brightest known Class I disks and has a small inclination of only 30 degrees. These observations will easily detect gap structure if it exists in younger sources. Such observations will either reveal the earliest known direct evidence of planet formation or put significant constraints on the age of which planets start to clear out material in protostellar disks. Disks around low-mass stars Disks and planet formation 2018-01-04T14:38:00.000
503 2023.1.00098.S 0 Constraining the stellar mass-loss-rate evolution on the AGB (and slightly beyond) It is believed that stellar mass loss increases as the star evolves along the AGB, and that it is higher the more massive the star is. However, there is little evidence that supports these beliefs. These are troublesome lacks of understanding since the mass-loss evolution of AGB stars is an important input parameter in population synthesis and galactic chemical evolution models, in which the mass-loss rates of AGB stars follow prescriptions based on the above expectations. It is therefore of great importance to empirically determine the mass-loss rate evolution for a large sample of AGB stars to improve the prescriptions. Of particular interest is the upper AGB and the early post-AGB where most of the stellar mass is expected to be lost. With this proposal, we aim to observe an equidistant and complete sample of the most extreme AGB stars in the inner Galactic Bulge in circumstellar CO lines. We will constrain their phase of strongest mass loss, and the sharp decline in mass loss expected to take place at the end of the AGB. This study will provide a much-needed and unprecedented empirical picture of the evolution of AGB gaseous mass loss at its most extreme phases. Asymptotic Giant Branch (AGB) stars, Post-AGB stars Stars and stellar evolution 3000-01-01T00:00:00.000
504 2022.1.01608.S 43 Mapping molecular gas exposed to strong X-rays, cosmic-rays and shocks of the supernova remnant Supernova (SN) feedback plays a key role in regulating galaxy evolution and star forming rate. Despite ample theoretical studies of SN feedback, it still lacks observational constraints on how SN energy is transferred to the ISM through different feedback channels such as X-rays, cosmic rays (CRs), and shocks. As the most luminous Galactic supernova remnant (SNR) in the X-ray band and energetic CR accelerator, W49B is an ideal laboratory to study SN feedback in detail. Recently, HCO+ emission and HCO+/CO have been proposed as a potentially useful probe of multi-channel feedback of SNRs onto molecular clouds (MCs). We propose ALMA HCO+ 1-0 and 3-2, and CO 3-2 observations toward W49B, aiming 1) to unveil how MC properties are controlled by X-rays, CRs, and shocks, and 2) to quantify the SNR energy transferred to the MCs. This observation will also provide crucial insight into the molecular heating and chemistry near extragalactic high-energy sources. Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) ISM and star formation 2024-06-27T20:39:23.000
505 2011.0.00028.S 0 The Effect of Extreme Environment on Protoplanetary Disks in Orion Protoplanetary disks, or "proplyds" are the sites where new Solar systems are born. While disk studies to date have focused on regions like Taurus and Ophiuchus for their proximity, stars rarely form in such isolated environments. In fact, there is clear evidence that our own Sun formed near a clustered OB association like Orion. To understand how planets form it is imperative that we study disk properties in regions representative of their origins. For this reason, we propose to survey 41 protoplanetary disks ("proplyds") in Orion in order to study fundamental disk properties in a massive star forming region. ALMA is uniquely capable of imaging dust and gas emission from the Orion proplyds with its combination of high frequency, sensitivity, resolution and spatial filtering properties. We will measure the masses and survival timescales of numerous disks, we will spatially resolve the dust emission to determine surface density profiles of the largest disks in the region, and we will attempt to detect molecular gas in Orion disks for the first time. The results of such observations will provide the first detailed view into how the clustered environment and UV radiation affect disk properties and evolution, and ultimately, allow us to assess the potential to form Solar system analogs in massive star forming regions. Disks around low-mass stars, Low-mass star formation Disks and planet formation 2014-01-03T18:04:00.000
506 2018.1.01302.S 7 Understanding the 3D structure of the disk around LkHa330 Circumstellar disks around young stars are the birthsites of planets. In the past few years, recent images of transition disks have revealed dust depleted inner cavities with asymmetric structures (spiral arms, dips, etc). An exciting explanation for these features is that they are the results of interaction of the disk with embedded planets. Our recent scattered light observations of the young transition disk around LkHa330 shows the presence of two asymmetric features that resemble spiral arms. Previous millimeter observations detected a cavity and a lopsided structure around the object, albeit at low angular resolution (0.35"), which prevents a direct comparison between the two types of observations. In this program, we propose to observe at high angular resolution in Band 6, the young transition disk around LkHa330 to detect millimeter counterparts to the features detected in scattered light. The combination of gas tracers, small dust (traced with scattered light image) and large dust grains (traced with ALMA) will allow to constrain the 3D structure of the disk, and understand the nature of the detected features. Disks around low-mass stars Disks and planet formation 2021-08-31T00:00:00.000
507 2019.1.00894.S 8 Molecular observations of the AGN Torus in Cygnus A We propose path-finder observations to detect CO emission from the archetype powerful radio galaxy, Cygnus A. The immediate goal is to make a first measurement of the CO luminosity of the recently discovered 'torus' region. Cygnus A, at a redshift of 0.0564, provides a unique laboratory to study the detailed physical processes in high (quasar-like), luminosity AGN right in our own backyard! We have discovered a structure in the nucleus of Cygnus A which may be free-free emission from the long-sought circumnuclear torus. The key to understanding this structure is to image the molecular gas and dust in the multi-phase, obscuring torus. Unfortunately, to date, no detection has been made of molecular emission from Cygnus A, although the existing limits are poor. In our path-finder observations, we will perform a search for CO emission at a resolution adequate to isolate the toroidal region, but not over-resolve any potential emission. These results will be used to plan high resolution imaging of the torus, to determine the dynamics and physical conditions in this unique AGN laboratory. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2022-09-01T22:41:01.000
508 2017.1.00006.S 22 The detached shells around DR Ser, V644 Sco, and S Sct We propose to observe the detached shells around the carbon AGB stars DR Ser, V644 Sco, and S Sct in CO(1-0). The shells were created during the high mass-loss rate phase of a thermal pulse (TP). The observations will allow us to determine the evolution of the mass loss from AGB stars during and after a thermal pulse. The amount of mass lost during the TP cycle is critical, as it limits the number of TPs an AGB star experiences, and hence the yields to the ISM. We will observe the shells and the extended circumstellar envelopes at a spatial resolution of 1"-1.5". The shells span the entire age range of known detached shell sources, allowing us to constrain the mass-loss rate shortly after the thermal pulse, and to follow the evolution of the shells until they get photodissociated after 10000 years. The proposed observations will yield the most detailed view of the evolution of the mass loss throughout the TP cycle on the AGB, and will constrain critical aspects of late stellar evolution. The results will move current research beyond the state of the art in understanding the chemical evolution of stars, the ISM, and galaxies. Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure Stars and stellar evolution 2019-11-29T10:45:33.000
509 2016.1.00940.S 17 3D Positions, Velocities, and Accelerations of SiO Masers in the Inner Parsec We propose to measure precise positions and velocities of circumstellar SiO masers close to the Galactic central black hole (Sgr A*). Position and velocity tracking of maser-emitting stars within 1~pc of Sgr A* will provide three-dimensional positions, velocities, and accelerations, enabling precise mass measurements at a variety of radii. One can therefore probe the stellar mass distribution in the inner parsec, provide a reference frame for near-IR observations of stars directly orbiting Sgr A*, and enable multiple direct probes of the black hole metric. 3D tracking of stars close to Sgr A* can test the equivalence principle, the ``no-hair'' theorem of black holes, and frame-dragging, but only if star-star scattering is not too large, which the proposed observations can address by precisely measuring the stellar potential at many different radii. The proposed observations will be combined with previous VLA and ALMA observations and will yield errors on position of roughly 2 milliarcseconds, errors on Doppler shifts of ~8 m/s, and errors on accelerations of ~5 m/s/yr. We require only 26 minutes of on-source integration (1.2 hours total). Galactic centres/nuclei Active galaxies 2018-11-24T19:11:02.000
510 2019.1.01484.T 190 Gamma-ray Burst Physics with ALMA: Direct Implications for the Explosions and Progenitors Gamma-ray bursts (GRBs) are the most luminous explosions in the Universe, and thus serve as unique laboratories for high-energy astrophysics and compact-object formation, as well as premier probes of the high-redshift universe. Observations of GRB "afterglows" provide critical insight into the energy scale and local environment of the bursts, thereby elucidating the explosion mechanism and nature of the progenitors. However, the existing extensive optical/X-ray afterglow data alone are degenerate with respect to these GRB properties. Millimeter and centimeter observations are critical for breaking these degeneracies, but pre-ALMA GRB follow-up has yielded a mm-band detection rate of <5%. We have begun to remedy the dearth of mm-band detections through our ALMA Cycle 4 & 6 programs, which were successful in detecting and characterizing mm emission from 3 GRBs. Following on this success, we now propose a mm-band survey comprising ALMA ToO observations of 4 GRBs to begin to address key unsolved questions. We will support these ALMA data with JVLA, ATCA, and GMRT observations, extensive optical follow-up (Gemini, Magellan, MMT, Keck), and X-ray monitoring (Swift, Chandra, XMM). Gamma Ray Bursts (GRB) Cosmology 2022-08-31T22:07:31.000
511 2021.1.00272.S 21 Small but mighty: Reconciling a paradoxical low-mass, ultra-dusty galaxy at z=4.27 The existence of dust in the early Universe and in low mass galaxies challenges our understanding of how metals are built up over cosmic time. We propose to exploit a strongly-lensed galaxy from the Frontier Fields at z=4.27 whose stellar mass is a mere 4e9Msun but where the majority of the star formation is obscured by dust. With an existing [CII] detection, this galaxy provides the ideal laboratory to explore primitive interstellar medium conditions, and put first constraints on the metallicity. Specifically, we propose to (1) quantify the ionized gas with [NII]205 and determine the neutral fraction of [CII], (2) measure the CO(4-3) luminosity and combine with [CII], [NII] and LIR to constrain the radiation field and gas density, and (3) use the 600 micron rest continuum emission to establish the total dust mass. Together these observations will clarify the unusual conditions that led to a low-mass, ultra-dusty galaxy only 1.4 billion years after the Big Bang. Sub-mm Galaxies (SMG), Gravitational lenses Galaxy evolution 2023-01-05T08:31:34.000
512 2018.A.00021.S 53 Confirmation of an Embedded Planet in the Disk of TW Hya Detecting planets during their formation is essential if we are to directly confront planet formation theories. Large programs dedicated to characterizing the substructure in protoplanetary disks have failed to detect any evidence of circumplanetary disks. Similarly, searches in the near infrared are hindered by the large opacities of dust which can hide any embedded planets. We have compelling kinematical evidence for a 2 Neptune mass planet at 75au and a position angle of 120 degrees in the disk of TW Hya. Using archival 12CO data we detect a large spiral in the gas velocities, two spirals in the temperature of the gas and a tentative region of enhanced velocity dispersion coincident with the end of the kinematical spiral. We request DDT observations for Band 6 data of comparable angular resolution and sensitivity to confirm with independent tracers (CO and CS) the presence and location of this embedded planet. While an expensive project, this will provide a clear case-study of ALMA's planet-hunting capabilities and demonstrate that such observations are the future of planet detection. Disks around low-mass stars, Exo-planets Disks and planet formation 2020-10-25T00:00:00.000
513 2018.1.00492.S 13 Interactions, Runaways, and Explosive Outflows from Compact Groups of Forming Massive Protostars We propose to image three NEW candidate explosive protostellar outflows with ~500 AU linear resolution in CO 2-1, SiO 5-4, other molecules, H30-alpha, and the 1.3 mm continuum. These massive star forming complexes are at distances of 1.5, 2.8-3.7, and ~3.7 kpc, contain massive and powerful outflows, multiple H2 fingers, and/or `bullets with morphologies similar to Orions BN/KL outflow. The BN/KL outflow located ~0.1 pc behind the Orion Nebula was powered by the dynamic interaction of several stars that resulted in their ejection as runaways. Our ALMA 1" images reveal hundreds of CO and SiO streamers expanding from the stellar ejection site with speeds of up to 150 km/s. ALMA observations of the three NEW targets will measure their energy and momentum inputs, locate their sources, and constrain the lifetimes and rate of explosive outflows. These powerful outflows represent a new type of feedback in massive star forming regions and contribute significantly to the self-regulation of star formation. Such protostellar explosions may be responsible for some recently detected luminous infrared-only transients observed by the Spitzer Space Telescope in nearby star-forming galaxies. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2020-10-03T17:30:51.000
514 2017.A.00035.S 17 Using eclipses to determine the size of a neutron star jet We recently made ALMA observations of a neutron star low-mass X-ray binary system, 3FGL J0427.9-6704, with the aim of detecting an eclipse of the mm emission from the jets. The source shows optical, X-ray, and gamma-ray eclipses, from which the donor star radius and orbital separation have been determined. This motivated our recent ALMA study to determine whether the mm emission was also eclipsed, and if so for how long. Our Band 6 observations showed a drop in flux density over the period of the eclipse that was not seen at Band 3. However, the low flux density and the stochastic variability of the source mean that this conclusion remains tentative. We therefore request a single 90-minute ALMA Band 6 DDT observation to confirm these intriguing recent results, and provide the first direct probe of the size scale and launching radius of jets from a neutron star. Pulsars and neutron stars Stars and stellar evolution 2018-11-28T06:32:39.000
515 2019.1.00949.S 77 A triple-image HST-dark but IRAC and ALMA-detected galaxy behind a lensing cluster Mounting evidence suggests that HST-dark galaxies are the progenitors of massive galaxies in their early forming phases, which are totally missed in the deep HST/WFC3 surveys. However, obtaining their spectroscopic redshifts becomes the current bottleneck because of their faintness in optical/near-IR and moderate (sub)mm fluxes compared with classical SMGs. Here we propose to use ALMA to obtain an unambiguous spectroscopic redshift of a triple-image HST-dark but IRAC and ALMA-detected galaxy system behind the lensing cluster MACS J0417.5-1154, by scanning for CO and CI lines in the Band-3 and 4 frequency ranges (~27 GHz each). This is one of the early, surprising outcomes of the on-going cycle-6 large program ALMA Lensing Cluster Survey. Our lens analysis indicates that this is an intrinsically faint (S_1.2mm ~0.6 mJy) HST-dark galaxy and observed as 3 bright (2-4 mJy) counter images, providing us with a unique target for the detailed study of HST-dark population. With the spectroscopic redshift, we will know the accurate magnification factors and therefore physical quantities such as stellar mass and gas mass, which are crucial to advance our study. Sub-mm Galaxies (SMG), Gravitational lenses Galaxy evolution 2021-04-15T07:32:51.000
516 2022.1.00958.S 33 Lord of the rings: the effect of dust traps and snowlines on the composition of planet forming material Almost all disks observed at high angular resolution show signs of ongoing planet formation but the formation mechanism and location of these planets remains unclear. The chemical composition of planets is set by the elemental abundances in the disk. The gas-phase elemental abundances in disks change drastically at the CO and H2O snowlines. Furthermore, pressure bumps in the disk trap the dust and with it ices preventing inward radial drift. Therefore, the location of the dust trap with respect to the snowlines is crucial in setting the composition of the gas available to planets. We propose to observe three transition disks where the CO snowline is expected to be inside the dust trap, thus trapping CO ice at large radii. We will compare these to archival data of disks where the CO snowline is outside the dust trap. In our sample, we first locate the CO and H2O snowlines using chemical tracers (N2H+, HCO+). Second, we quantify the elemental C/O abundance ratio using C2H observations. These observations will assess the effect of dust traps on the chemical composition of the planet forming material, a crucial ingredient to understand where the exoplanets observed to date have formed. Intermediate-mass star formation ISM and star formation 2023-10-26T08:45:47.000
517 2018.1.01601.S 18 The Making of a local galaxy cluster: star formation and AGN feedback in a proto-cluster at z=1.69 We recently discovered a galaxy proto-cluster candidate around a FRII radio-galaxy at z=1.69 in the deep, multi-band field around the z=6.3 quasar SDSSJ1030+0524. Archival VLT/MUSE data covering the Eastern part of the system show an overdensity of blue star forming galaxies at this redshift. Most of these galaxies are distributed in an arc-like structure around a region of diffuse X-ray emission, possibly hot gas shock-heated by the FRII jet. This may argue for a causal connection between the energy released by the AGN and the on-going star formation (positive feedback). To map the overall distribution of proto-cluster members and confirm the possibility that feedback from the AGN is promoting star formation among them, we propose to observe with ALMA the entire field around the FRII galaxy and detect CO(2-1) emitters at z=1.69. Similarly to what is observed in the z=2.2 Spiderweb proto-cluster, our observation will also probe any reservoir of cold gas extending on tens of kpc scales around the central radio-galaxy and/or distributed across the entire proto-cluster, hence revealing the interplay of feedback and star formation at the peak formation epoch of galaxy clusters. Outflows, jets, feedback, Galaxy groups and clusters Active galaxies 2020-03-04T20:43:19.000
518 2015.1.01178.S 10 ALMA Observations of z~6.7-6.8 Galaxies with Strong Optical Nebular Emission: Re-Evaluating ALMA's Potential for Detecting z>6 Galaxies ALMA is expected to change our view of the high-redshift Universe: Because of the strong negative K correction, ALMA continuum imaging should be able to detect a z~10 galaxy as easily as a z~1 galaxy for a given infrared luminosity; Also, the strong [CII] 158 um line is expected to serve as a great redshift marker and a star-formation indicator, especially at z>6, where the intergalactic medium (IGM) becomes increasingly neutral and heavily absorbs Ly-alpha emission. Despite this great expectation, detecting z>6 galaxies with ALMA remains challenging, suggesting the possibility that galaxies at such high redshift may be rather poor in dust and metal. To address this issue further, we propose to observe two bright z=6.7-6.8 galaxies with ALMA. These galaxies are cluster-lensed, so their intrinsic SFRs are ~10 Msun/yr or less. Also, they show a sign of having strong nebular emission in the rest-frame optical. Together, these factors may increase the chance of [CII] and dust continuum detections, thereby shedding new light on the properties of z>6 galaxies. This is a Cycle 2 Priority B program with a time allocation of 6.5 hours, but no data have been obtained so far. Lyman Alpha Emitters/Blobs (LAE/LAB), Gravitational lenses Galaxy evolution 2017-05-02T21:03:30.000
519 2019.1.01153.S 7 Localizing active deuterium fractionation chemistry in a planet-forming disk Molecular D/H ratios are commonly used as probes of the thermal history of Solar System volatiles, but it is currently unclear whether elevated D/H ratios originated in the Solar Nebula or in the pre-Solar cloud. Previous ALMA observations of DCO+, DCN, and N2D+ have revealed an active deuterium fractionation chemistry in analogs to the Solar Nebula, i.e. in protoplanetary disks. Whether the observed disk deuterium fractionation chemistry affects the composition of forming planetesimals is yet unclear, however, due to poor constraints at which disk elevation the observed molecules originate. To address this question we propose to observe DCN and DCO+ 2-1 in the disk of TW Hya. When combined with exisiting observations of 4-3 and 3-2 lines, the new observations will put tight constraints on the excitation conditions of DCN and DCO+ in this well-studied disk, and further whether they originate in the planet-forming disk midplane, elevated molecular layer or disk atmosphere. These observations will also link DCN and DCO+ abundances with specific disk thermal environments, enabling us to use these molecules as accurate probes in disks with fewer line observations. Disks around low-mass stars Disks and planet formation 2022-05-06T16:26:35.000
520 2012.1.00817.S 0 Hot HCN in LIRGs - probing the dusty core and dense wind We propose band 7 ALMA observations of vibrationally excited HCN 4-3 v=1f and the rotational ground state v=0 to probe the hot dusty cores and outflow acceleration regions of three luminous LIRGs and ULIRGs. We know from dust models that effective HCN pumping can only occur for dust brightness temperatures T(dust)> 80 K which occurs only in the inner 10-50 pc of galaxy nuclei. Thus with the vibrationally excited HCN we can probe the very nuclear excitation and dynamics. We have selected three objects with luminous HCN emission, IR-pumped emission and evidence of massive molecular outflows. There is mounting evidence that molecular outflows are common in LIRGs and ULIRGs and are important feedback mechanisms for regulating star formation and the accretion onto supermassive black holes (SMBHs). The proposed observations enable us to study the very onset of the dense molecular outflow as well as probing inside the optically thick dusty atmospheres of buried AGNs or compact starbursts. Submm and mm vibrational lines are a promising new tool for studying the extreme, hot cores of luminous infrared galaxies and AGNs - near and far. Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Active galaxies 2015-06-05T19:20:20.000
521 2019.1.00746.S 6 Pushing ALMA to the limit: 100pc imaging of spectacular [CII] cavities in a z=6.6 quasar host galaxy Recently, we reported high spatial resolution (~0.076",410pc) ALMA imaging of the dust continuum and [CII] line in a luminous quasar host galaxy at z=6.6. The unprecedented high resolution of the observations reveals a complex morphology of gas within 3 kpc of the accreting central black hole. Strikingly, we locate impressive [CII] cavities in the gas distribution (with diameters of 0.5kpc), offset from the black hole. The current data are insufficient in resolution to determine if they are created by interactions with nearby galaxies (leading to broad tidal features), or due to energy injection by the central accreting black hole (leading to confined, narrow shock fronts). Given the brightness of the [CII] emission on 400pc scales, observations at an incredible 100 pc resolution (0.02" in C43-9/C43-10) to resolve the rims of the these cavities are now within reach. This resolution also matches the sizes of regions that give birth to super star clusters in the galaxy and will allow us to zoom into the central region harboring the black hole. The proposed observations will showcase the unprecedented capabilities of ALMA in studying a forming massive galaxy in the reionization epoch. High-z Active Galactic Nuclei (AGN) Active galaxies 2022-11-26T00:09:54.000
522 2018.1.01031.S 169 Revealing dust processing in the young supernova remnant 1E\,0102.2-72129 in the SMC Oxygen-rich supernova remnants (SNRs) are observed within a few thousand years after a core-collapse supernova, prior to significant mixing of the SN ejecta with interstellar gas. They provide clues into stellar nucleosynthesis in massive stars, SN explosion mechanisms, and dust processing by/in core-collapse SNRs. Here, we propose to map the cold dust in the O-rich SNR 1E0102.2-7219 using 4 ALMA Bands to 1) accurately measure for the first time the mass and distribution of newly synthesized dust in un-shocked ejecta in this system, 2) track the processing of this newly synthesized dust as it encounters the reverse shock, and 3) characterize the cold dust, CO, and C, associated with a torus of ejecta surrounding the recently identified central compact object in the system. This dataset will be complemented by existing VLT/MUSE, HST, Chandra, Spitzer and Herschel datasets. These observations will provide new observational constraints regarding the formation and destruction of dust in the wake of core-collapse supernovae in the low metallicity environment of the SMC, with implications for the dust formation in the early Universe. Supernovae (SN) ejecta Stars and stellar evolution 2020-11-26T19:03:05.000
523 2015.1.01415.S 10 Outflow launching scales in a Class I protostar In this program we will investigate the innermost regions of a Young Stellar Object to trace the kinematics of the molecular gas very close to the launching point of the protostellar outflow. With ALMA in its largest configuration currently offered, it is now possible for the first time to directly trace molecular gas at the relevant spatial scales, i.e., radii of ~3 AU. We aim to discriminate whether outflow launch regions are confined to a few stellar radii or that extended disk winds also play a role. To achieve this, we will directly compare our ALMA spectral line profiles, at unprecedented angular resolution, with our numerical simulations that are specifically developed with the aim of simultaneously resolving small outflow launching scales as well as larger, traditionally observable length scales. At the same time, our observations will be sensitive to disk rotation signatures, allowing us to determine any deviations from pure Keplerian rotation in the very inner disk. This would have implications for our understanding of protostellar disk dynamics. Outflows, jets and ionized winds, Low-mass star formation ISM and star formation 2016-12-10T16:28:34.000
524 2016.1.00605.S 0 Polarization of SNR 1987A: probing the shock structure and the compact remnant Polarization of the synchrotron emission from supernova remnants (SNRs) gives insight into the mag- netic field properties, particle acceleration mechanisms at the shock front, asymmetry, and evolution of the compact remnant. Supernova (SN) 1987A in the Large Magellanic Cloud, the brightest SN in 400 years, is a unique laboratory to investigate polarized emission generated by the elusive compact remnant and by the shock front. Polarization is critical to accurately locate a possible pulsar wind nebula, and to correlate the degree of efficiency of the particle acceleration process with the topology of the magnetic field. ALMA Cycle 4 Full Polarization observations, with resolution of 10% of the remnant size, provide the opportunity to detect polarized emission in SNR 1987A for the first time. Supernovae (SN) ejecta, Pulsars and neutron stars Stars and stellar evolution 2019-07-17T21:48:43.000
525 2016.1.00656.S 51 Filling the gap of CO line emission detections at high redshift We propose to obtain CO emission maps on 5 strongly lensed main sequence galaxies at redshifts between 1 and 2.5. Similar studies have been done mainly in the most massive and highly star-forming galaxies that represent a small fraction of the full SFR density of the Universe. These observations will allow us to characterize the molecular gas content in galaxies with intrinsic SFR lower than 100 solar mass per year. This type of galaxies, until now, have been elusive in the detection of molecular gas. The lensing power and good models of the Hubble Frontier Fields galaxy clusters allow us to explore a new range of 1-10x10^9 Msun galaxies, which is out of reach in CO for ALMA. Besides the gas mass, we will be able to obtain depletion times, dynamical mases, CO distribution sizes and star formation effiencies in galaxies comparable to local spirals. The observations will reveal how the process of transorming molecular gas into stars evolves from z~2 to z~0. Gravitational lenses Cosmology 2018-04-12T13:36:49.000
526 2018.1.00085.S 88 The ISM at z~7: Deploying a successfully piloted technique to find the brightest [CII] emitters at z>6.5 Astronomers have long anticipated using [CII] to pursue a physical study of galaxies in the epoch of reionization. Yet current probes with ALMA have had a low yield in identifying bright [CII] emission at z>6. Perhaps this could be due to the almost exclusive targeting of galaxies with spec-z's from Lyman alpha? Seeking a different approach, we recently executed a pilot program pursuing efficient line scans on two luminous galaxies at z~7. Amazingly, with just 1 hour of observations, 2 >=6 sigma [CII] lines were found, exceeding the luminosity of all prior detections in z>6.1 galaxies. The surprising success of our pilot suggests that luminous [CII] galaxies do exist at z>6, but perhaps not in those galaxies showing Lyman-alpha emission. Here we propose to extend our pilot program to target 6 more extremely luminous galaxies at z~7 with precise photometric redshift constraints (leveraging 2 sharp spectral features). Our program would measure redshifts for sources, constrain the masses of the brightest galaxies at z~7, and allow for an extensive suite of follow-up activities. Lyman Break Galaxies (LBG) Galaxy evolution 2020-02-22T17:17:58.000
527 2018.A.00046.S 246 The host properties and environment of high-redshift radio galaxies with ACA It is now accepted that radio-emitting jets might be one of the main ingredients shaping the evolution of massive galaxies in the Universe. There is wide observational evidence that the super-massive black holes responsible for such jets reside in the most massive galaxy population, which in turn reside in large scale structures. This trend seems to have settled long time ago, making radio-AGN a natural lighthouse of such structures in the early Universe. However, pinpointing these early radio-AGN and studying their hosts has been harder to accomplish, with only recent reasonable numbers of radio-AGN host studies coming to light at z>2. This proposal aims to provide a statistical understanding of radio-AGN found within 4deg2 in the ELAIS-S1 field known to have the lowest foreground contamination, hence ideal for mid-IR observations with JWST. We propose to observe 41 high-redshift radio-AGN (selected either via their ultra-steep radio spectrum or extreme IR-to-radio flux ratios) at 1.3mm with ACA down to rms=0.2mJy. The ACA field of view will in addition allow us to assess the star-formation activity in the local environment of these galaxies (within a radius of ~180kpc at z~2). Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies Active galaxies 2019-07-30T00:00:00.000
528 2017.1.01006.S 35 Cores on the cusp of star formation We propose to observe with ALMA two nearby, centrally concentrated cores in the Ophiuchus molecular cloud on the cusp of forming a low mass protostar or first hydrostatic core. Despite lacking detected protostars, ALMA Cycles 0 and 2 observations reveal compact continuum condensations (< 1", or 140 au) embedded within elongated structures toward both cores. The proposed continuum observations in Bands 3, 4, and 7 will reveal the core structure at matched 0.6" resolution (80 au) to determine the dust emissivity, masses, and density profiles via radiative transfer modeling. We will also perform a suite of molecular line observations at 1" (140 au) resolution to i) use the gas kinematics to to measure infall, and distinguish rotationally-supported disks from collapsing pseudodisks; ii) determine the deuterium fractionation of HCO+ and N2H+ across the cores to constrain the luminosity of any undetected, embedded source; and iii) confirm the tentative lack of low-velocity outflows. These proposed observations will provide, for the first time at ~100 au scales, comprehensive physical, kinematic, and chemical pictures of two rare cores caught at the earliest stages of star formation. Low-mass star formation, Astrochemistry ISM and star formation 2019-02-26T19:29:53.000
529 2016.2.00115.S 42 Star formation inside galactic outflows: properties of the associated molecular gas and star formation efficiency While galactic outflows are generally invoked to suppress star formation, recent models have proposed that the outflowing molecular gas can undergo star formation. This new star formation mode would have fascinating important implications, since the stars formed in the outflow would have high radial velocities, hence this mode may contribute to the morphological and dynamical evolution of galaxies. We have recently discovered evidence for star formation occurring in the outflow of a nearby galaxy. Stars are forming at a rate of about 15-30 Msun/yr and with radial velocities of a few hundred km/s. We propose to characterize the properties of the molecular gas in this star forming outflow with a 7m-array exploratory programme aimed at observing multiple CO transitions and a few tracers of the dense molecular gas. The goals of the observations are: 1) obtain a first assessment of the content of molecular gas and of its distribution in the outflow, hence providing the star formation efficiency of this new mode of star formation; 2) characterize the properties of the outflowing molecular gas, hence shedding light on the conditions that enable star formation in this unusual environment. Outflows, jets, feedback Active galaxies 2018-11-17T19:51:57.000
530 2022.1.00522.S 40 ALMA [OIII]88um Spectroscopy for the Most Luminous Galaxy Candidate at z~10 We propose [OIII]88um observations for an extremely luminous galaxy candidate, XMM3-3085 at z~10.2, whose high redshift is suggested by recent HST grism spectroscopy. XMM3-3085 is the most luminous galaxy candidate at z>10, and such a luminous system is not expected theoretically, indicating an unusually vigorous period of early star formation. Importantly, the progenitors of such luminous systems would then be readily within reach of JWST. Noting ALMA's demonstrated role in confirming redshift estimates from HST and ground-based campaigns, we request a modest allocation to confirm the HST-based redshift using [OIII]88um for this remarkable z>10 source. Confirmation would permit more ambitious joint spectroscopic campaigns exploiting both ALMA and JWST on a timely basis, thereby strengthening evidence for a rapid emergence of luminous primeval systems. Lyman Break Galaxies (LBG) Galaxy evolution 2023-10-06T11:23:40.000
531 2012.1.00681.S 5 Locating the CO Snow Line in Protoplanetary Disks Snow lines, or condensation fronts, in protoplanetary disks are key ingredients in planet formation models and locating the snow lines is important to enhance our understanding of the structure of planetary systems. We propose to locate the CO snow line in the protoplanetary disks by searching for the signatures of CO freeze-out: 1) directly imaging the C18O 2-1 radial brightness change due to the CO freeze-out in the nearly face-on disk of TW Hya, and 2) resolving the N2H+ 3-2 emission to investigate whether N2H+ traces the CO snow line in the disks of TW Hya and HD 163296. The proposed observations will put strong constraints on our understanding of disk temperature profiles, and potentially provide a powerful chemical imaging tool to constrain CO snow line locations in large samples of disks. Disks around low-mass stars Disks and planet formation 2015-08-01T15:36:52.000
532 2016.1.00162.S 36 Millimeter and Submillimeter Polarization of Disks: Direct Emission or Scattered Light? HL Tau is the only known T Tauri Star to have a resolved polarization detection in the disk. Since grains align with the magnetic field, polarization from dust emission is typically thought to trace the magnetic fields. However, in the last year four theoretical papers have suggested that polarization at (sub)millimeter wavelengths may be due to Rayleigh scattering off grains in a disk. Currently, we are unable to determine if polarization from disks is from scattering, grain alignment, or a combination of the two. ALMA has observed many 10s of hours of polarimetric observations toward disks already, but none of these observations can truly distinguish between different polarization mechanisms, making it very difficult to interpret any of these observations. We propose to observe polarization in the disk of HL Tau. With deep, high-resolution, and multi-wavelength polarization observations, we will be able to take into account morphological, wavelength-dependent, and optical depth effects, and we will accurately determine whether polarization from disks comes from scattering, grain alignment, or a combination of the two. Disks around low-mass stars Disks and planet formation 2018-06-23T23:36:13.000
533 2016.1.00761.S 30 Are Brown Dwarf disks in rho-Oph truncated? Our successful systematic Cycle 1 survey for dusty disks around very low mass stars and brown dwarfs (VLMO) in rho-Oph has resulted in two very interesting results: the Mdisk/Mstar ratio appears lower than in more massive TTauri systems and the two brightest disks in the sample are consistent with small dusty disks with sharp edges. Are these the first direct observational hints of dynamical truncation of VLMO disks, predicted by some formation theories, or the effect of growth and segregation of large grains? We propose to answer this question by resolving the dust and gas distribution in a small sample of rho-Oph VLMO disks from our survey. Our observations will directly test dust and gas evolution models in VLMO disks and provide a first test of the dynamical interaction channel for VLMO formation. Disks around low-mass stars Disks and planet formation 2018-09-05T16:07:13.000
534 2017.1.00787.S 20 Physical Properties of Young Galaxies Measuring the properties of young galaxies is central to understanding galaxy assembly and the reionization of the universe. We have spectroscopically confirmed many sub-L* galaxies at redshift 5.7. We propose ALMA [CII] observations that will measure their redshifts, thereby determining the offset of the Lyman-alpha emission line from the systemic redshift. Together, the Lyman-alpha and [CII] line properties will constrain the velocity and neutral column density of gas flows between these galaxies and their environment. By comparing the velocity offsets to those observed at cosmic noon (z ~ 2 - 3), we will gain important insight into the evolution of the neutral gas distribution and kinematics in galaxies. This information will strongly impact the interpretation of the rapid decline in Lyman-alpha emitting galaxies between redshifts 6 and 8, potentially slowing down the inferred progression of cosmic reionization. Lyman Alpha Emitters/Blobs (LAE/LAB), Starburst galaxies Galaxy evolution 2019-06-13T21:15:03.000
535 2023.1.00185.S 0 Confirming the presence of star formation in the most luminous quasars The FIR continuum emission from quasar host galaxies is generally considered to be an indicator of the amount of their star formation with little contribution from dust heated by the quasar itself. Recently, it has been shown using ALMA that the most luminous quasars at z~2 have SFRs (based on rest-frame 285um luminosity) consistent with the star-forming galaxy population. However, there are claims, based on simulations, that AGNs can heat dust, even over galaxy-wide scales, above that produced by the torus, thus SFRs can be overestimated if based solely on the FIR luminosity. Here, we aim to test this by measuring whether the star formation is within dense molecular gas by mapping the CO (J=5-4) emission on galaxy-wide scales at high signal-to-noise for three of the most luminous quasars at z=2 with ALMA continuum measurements already available. Resolution of this issue has wide implications on AGN science with ALMA, particularly the role of quasar feedback in quenching star formation. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 3000-01-01T00:00:00.000
536 2017.1.01542.S 75 Outflow and Infall to Massive Protostars We propose to investigate the outflow and infall phenomena in 8 sources which are part of a larger MIR/FIR sample already observed with SOFIA-FORCAST as part of the SOMA survey. These observations will allow us to understand how the infall/outflow processes depend on the evolutionary stage of the source and to place constraints on parameters such as the mass loss rate and infall velocities, which are needed to test models of high-mass star formation. Additionally, these data will provide the necessary molecular counterparts to the smaller-scale ionized jets and/or photoionized hypercompact HII regions from our cm-wave observations. This will allow us to study their association at the proposed resolution of 1.2". We will also obtain sensitive continuum maps that, in combination with our ALMA 1.3 mm data from cycle 3, will allow us to distinguish between the free-free emission and dust continuum regions in these sources. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 2019-08-02T17:21:43.000
537 2019.A.00003.T 180 Gravitational millilensing as a tool for studying the microarcsec-scale structure in PKS1413+135 We have recently identified a new type of symmetric achromatic variability in light curves of active galaxies, which we suggest to be due to gravitational lensing. This allows us to probe lenses in the mass range of 10^3-10^6 solar masses, which have been challenging to detect with other methods. We propose ACA standalone mode observations of the radio source PKS 1413+135, which has previously shown five SAV events in its light curve over the past 27 years and which shows indicators that a new event has recently started and will be observable during cycle 7. The main goal of this proposal is to find out if the variations are achromatic up to 345 GHz (band 7) frequencies. We request 22 observations separated by approximately 14 days to monitor the flux density evolution during the event. Depending on the outcome, we have a unique opportunity to study gravitational milli-lensing, plasma lensing or intrinsic variability in relativistic jets. Gravitational lenses Cosmology 2020-09-11T18:34:51.000
538 2011.0.00172.S 0 The Life Cycle of the Molecular Gas in the Nearest Nuclear Starburst: GMCs, Molecular Superwind, and Feedback v2.5 We propose to observe NGC253, the nearest nuclear starburst, with early ALMA: with a modest investment of ALMA ES band 3 we will measure two key parameters fundamentally related to the evolution of starbursts: 1) the mass and energetics of the molecular gas entrained in the galactic superwind, thought to be the main way to quench massive starbursts, and 2) the properties of Giant Molecular clouds, thought to drive the high star formation efficiencies in a starburst. These goals require a 7-point CO (1-0) mosaic using the compact configuration covering the launching point of the wind and the H-alpha streamers, and a 3-point mosaic targeting high density tracers (one spectral setting) centered on the nuclear starburst and including the nearby region of the bar. The proposed setups will result in a >10-fold increase in sensitivity over existing data on a significantly larger area. The resulting images will provide a visually stunning illustration of early ALMA capabilities. Starbursts, star formation, Spiral galaxies Active galaxies 2013-06-19T19:41:00.000
539 2023.1.00038.S 0 Complex organic imaging towards G+0.693-0.027, the ISM COMs Rossetta Stone During the last 5 years, the source G+0.693-0.027, in the Sgr B2 Galactic center complex, has become one of the most prolific molecular emitters with more than 120 species detected today. Moreover this source is a strong complex organic molecule (COM) emitter, with many detected species of prebiotic interest. Although the molecular abundances are well constrained with unresolved single-dish observations, it is obvious from shallow interferometric observations that the understanding of the ISM chemical processes requires the spatial information probing the association between species. G+0.693-0.027 is likely the best source to provide this information due to its observed 10''-20'' extended emission, well suited for ALMA observations. The low excitation in this source provides a clean spectrum, different from the line crowded observations towards hotter sources. The advent of ALMA Band 1 is ideally suited to study the distribuiton of prebiotic COMs like ethanolamine, and even to detect or obtain robust limits to the detection of glycine and its isomers. Here we propose a very deep Band 1 observation towards G+0.693-0.027 to probe, for the first time, the origin of ISM COMs. Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 3000-01-01T00:00:00.000
540 2015.1.01133.S 5 Harnessing the power of CI as a tracer of H2 in starburst galaxies Molecular gas fuels star formation and is a key driver of galaxy evolution. Unfortunately, gas mass estimates rely on the optically thick rotational lines of 12CO, where the relationship between line emission and column density quickly breaks down. Furthermore, in extreme star formation environments, UV-fields and cosmic rays act to diminish CO as a H2-tracer.We propose 0.7" imaging of the fine-structure line of atomic carbon, CI(3^P_1 - 3^P_0), towards the central starburst in NGC253. This will be the first sensitive CI map of a starburst galaxy, it will resolve molecular clouds (~20pc) and yield the most detailed study to date of CI in extreme starformation conditions. Using CI-to-H2 conversion factors predicted by our state-of-the-art simulations, we will infer H2 column densities across the region. These will be compared with results from the optically thin CO isotopologues - and from the dust emission - in order to, for the first time, calibrate CI as a H2-tracer on ~20pc scales in an intense starformation environment.Our findings will have significant implications for high-z studies of starburst galaxies where CI could replace CO as a tracer of H2. Starbursts, star formation Active galaxies 2017-06-29T12:18:57.000
541 2023.1.00792.S 0 Identifying HI-absorption-selected galaxies at z~4 The relation between the HI reservoirs traced by high-z damped Lyman-alpha absorbers (DLAs) and their associated galaxies has been an open question for 3 decades. ALMA CII-158-micron searches have obtained the first identifications of such HI-selected galaxies at z~4, finding a number of surprises, including a high detection rate of CII-158 micron emission in high-metallicity ([M/H]>-1.35) DLAs, large impact parameters to the DLA sightlines suggesting absorption in the CGM, and the first case of a cold disk galaxy at z>4. We propose to use ALMA to search for CII-158-micron emission from galaxies associated with all z>3.6 DLAs in the ALMA sky with [M/H]>-1.35. The proposed observations will double the number of high-metallicity DLAs with such searches, allowing us to identify the associated HI-selected galaxies and test whether high-metallicity DLAs continue to show a high CII detection rate, test whether extended, enriched HI envelopes are a generic feature of high-z galaxies, identify candidate rotating disk galaxies at z~4, and compare the CII emission and low-ionization metal absorption lines to trace the large-scale dynamics of the HI-selected galaxies and their CGM. Damped Lyman Alpha (DLA) systems Cosmology 2025-04-05T16:49:13.000
542 2017.1.00908.S 19 The Molecular Gas and Dust Distribution of the Hot Dust Obscured Galaxy W0410-0913 The WISE mission has recently identified a rare population of high-redshift, hyper-luminous infrared galaxies, all with bolometric luminosities above 10^13 L_Sun, and many exceeding 10^14 L_Sun. Characterized by their extremely red mid-IR colors and very hot dust temperatures, these hot, dust obscured galaxies (Hot DOGs) likely probe a key stage in the galaxy evolution paradigm. During cycles 2 and 3 we have carried out observations of the [CII] emission line which confirm these galaxies are in a cathartic stage. One of these Hot DOGs, W0410-0913, shows a very extended dust continuum and the highest [CII] deficit ever measured. We request here deep, high-resolution observations of the CO(6-5) emission line and the nearby dust continuum to study the physical state of its ISM. Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Active galaxies 2019-01-26T01:00:44.000
543 2013.1.01200.S 30 The mass-loss rates of Red Supergiants The evolution of massive stars and the nature of supernova (SN) progenitors are highly sensitive to the amount of mass lost during a star's lifetime. Though much attention has been paid to the mass-loss rates of hot massive stars, the winds during the RSG phase have recieved relatively little attention, despite the fact that 10% of the envelope can be ejected during this short phase. The main reason for this is that most of the mass ejected is in the gas phase, but this material is difficult to detect - gas mass-loss rate measurements for even nearby RSGs have required several hours' integration with e.g. the JCMT. With ALMA, it is now possible for the first time to measure the gas mass-loss rates of large sample of RSGs. In this proposal we target a coeval cluster of RSGs, where all stars have roughly the same mass and chemical composition, with the only variable being how far along the RSG branch the stars are evolved. We will therefore be able to study how the mass-loss rates of RSGs increase with evolution, as their dusty envelopes become more opaque, and ultimately determine the total mass lost prior to SN - the key parameter in the appearance of the SN explosion. Main sequence stars Stars and stellar evolution 2016-06-19T03:04:00.000
544 2017.1.00190.S 120 Physics of the interstellar medium of galaxies in the reionization era: the [OIII]-to-[CII] line ratio II We propose a continuation of our high priority program: the first systematic survey of the ratio of the [OIII] 88 micron line to the [CII] 158 micron line of bright galaxies at 6 Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) Galaxy evolution 2019-09-21T16:02:49.000
545 2018.1.00375.S 57 Sulfur chemistry in the transition zone of low-mass protoplanetary systems Tracing the chemical evolution during the forming processes of Sun-like stars and planetary systems is crucial for understanding the origin of the Solar system. Our previous observations towards two protoplanetary systems (a Class 0 and a Class I) show significant chemical differentiation in their transition zones, i.e., the CS line traces the infalling-rotating envelope (200 AU), while the shock-enhanced SO line traces the centrifugal barrier (100 AU). Therefore, both sources are ideal laboratories to investigate the time-dependent sulfur chemistry. We propose to observe Band 5 lines of H2S, H2CS, SO2 and CCS towards both sources at a linear resolution of 70 AU. Incorporating our previous ALMA data and our well-developed gas-grain model, these observations will allow us to (1) image the sulfur grain reservoir H2S for the first time towards low-mass protoplanetary systems; (2) investigate the origin of the SO near the centrifugal barrier; (3) construct the gas temperature profile of each source from the ~1000 AU protostellar envelope down to the 70 AU transition zone; (4) draw a clear picture of the sulfur chemistry towards the transition zone in an evolutionary context. Disks around low-mass stars Disks and planet formation 2020-09-11T15:36:54.000
546 2018.1.01115.S 1915 A Large Unbiased and Complete Survey of CO in the Small Magellanic Cloud The Small Magellanic Cloud (SMC) is the only laboratory to study the low metallicity ISM at high spatial resolution, and yet we still do not know where the CO emission exists. We propose to use the ACA in standalone mode to map a 1.0 x 0.5 degree (1 kpc x 500 pc) region of the SW Bar of the SMC in 12CO, 13CO, C18O (2-1) covering a large fraction of the recent star formation, dust, and HI gas. With this new map we will be able to catalog CO clouds and clumps down to a mass of ~1000 solar masses and with a factor of ~15x increase in luminosity sensitivity over the existing large-scale single-dish APEX map. With only the ACA and the minimum integration time per pointing, we will produce a map of extragalactic CO with the greatest mass sensitivity and covering ~1.5 pc to 1 kpc scales. Once we have an accurate account of the CO-emitting gas we will be able to measure the CO luminosity function, the dynamical state, how CO brightness relates to environmental properties, and variations in X(CO). Further analysis of the data will allow us to understand the turbulence properties across all scales and how the CO emission relates to the HI gas at low metallicity. Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds ISM and star formation 2019-11-09T19:15:47.000
547 2018.1.01833.S 117 The disks around low-mass stars in the solar neirborhood Debris disks are signposts of successful planet formation in some stars. Several years of studies have revealed a broad population of evolved disks. This population shows a clear decrement in the frequency of disks towards later spectral type stars. The origin of this trend is not clear, but evidence suggests there is a segregated evolutionary path that might depend on the stellar mass/temperature. M-stars are the most abundant stellar objects in the Galaxy but the fraction of M-stars harboring warm debris disk seems to be very low, while complete surveys looking for the cold debris disks are not complete yet. Here we propose to observe a small sample of M-stars in the Solar neighborhood, all showing clear signs of harboring circumstellar material. We will use the ACA standalone to detect the cold component of debris disks around nearby M-stars, in order to determine the amount of dusty material present around the dwarfs and, this way, to constrain the formation and evolution of the very close M-stars population. Debris disks, Disks around low-mass stars Disks and planet formation 2020-09-08T16:22:13.000
548 2018.1.00656.S 10 Radio-mode feedback at the highest redshifts: ALMA/VLBA synergistic observations of the brightest radio source at z~6 Radio-mode feedback is a key ingredient in current formation theories of massive galaxies. The interactions between radio jets and the interstellar medium are thought to have a defining role for the co-evolution of the central supermassive black holes and galactic stellar masses. However, observational constraints on these feedback processes are still very limited or almost non existent beyond z>1, where theoretical galaxy formation models can be best constrained. We recently discovered a quasar that is the brightest radio source known at z~6 (by an order of magnitude). VLBA DDT observations (at 0.02"/120pc resolution) revealed a morphology similar to a radio galaxy with a total extent of 1.8kpc (0.3"). Here we propose ALMA matched-VLBA-resolution observations of the dust continuum and [CII] emission to study the interstellar medium of the only z~6 quasar known with evidence of powerful jets. This dataset will allow us to test whether the dust and gas in the host galaxy are affected by the ejected radio lobes. We will search for direct evidence for radio-mode feedback as an important process during the formation of a massive galaxy within the first billion years of the universe. Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback Active galaxies 2021-02-07T16:58:17.000
549 2021.1.01603.S 6 Sub-kpc mapping of the [CII]/dust in the highest-redshift ULIRG at z=7.3 Recent studies have revealed the existence of particularly massive galaxies within the first Gyr after the Big Bang. These galaxies push the limits of galaxy evolution models, but detailed physical studies have been limited due to a lack of bright, spectroscopically-confirmed targets. Excitingly, ALMA has now discovered a massive (M_*=1.3x10^10 Msol), extremely [CII]- and IR-luminous galaxy (L_[CII]=2.0x10^9 Lsol, L_IR=1.1x10^12 Lsol) at z=7.3 -- the highest-redshift ULIRG known to-date. This exceptional source shows a clear [CII] velocity gradient, a clumpy UV morphology, and a possible outflow/companion, but the current ALMA data are too low-resolution to determine the mechanism(s) powering its extreme IR luminosity or how it is building its stellar mass. We propose sub-kpc (0.15/780pc) imaging of the [CII] and dust continuum in order to reveal the morphology and kinematics of the gas and dusty star formation. Together with the existing HST imaging and approved JWST NIRSpec/IFU imaging -- which will map the unobscured stellar emission on similar scales -- the proposed observations will provide an unprecedented view of massive galaxy formation just 700Myr after the Big Bang. Sub-mm Galaxies (SMG) Galaxy evolution 2023-09-09T00:00:00.000
550 2022.1.00638.S 0 Dust evolution in planet-forming disks: from early stages to the end of disk lifetime Planet formation takes place in disks of gas and dust that orbit young stars. The fundamental question of how disk constituents - the gas and solids - evolve with time is yet unanswered, but the ongoing ALMA Large Program AGE-PRO was designed to answer this question for the gas component. However, constraints derived on the dust constituent from these observations will be much limited. Thus, we propose to obtain ALMA multi-wavelength continuum observations for the full AGE-PRO sample at 2.9 and 1.8 mm, to establish how the solid component in disks evolves with time and to compare with dust trapping and radial drift models. We will constrain properties of solids (mass, temperature, size distribution, albedos, etc.) and dynamical parameters (gas-to-dust ratio, Stokes number, Toomre parameter), and infer how dust evolution and dust properties change radially for each disk. These new measurements, coupled with the extensive knowledge to be derived for the sample in the gas, will allow for a complete picture of how gas and solids evolve for the different evolutionary phases investigated: the embedded disk phase, the middle-age, and the end of the disk lifetime. Disks around low-mass stars Disks and planet formation 2024-07-17T21:47:44.000
551 2015.1.01316.S 10 Search for an Intermediate Mass Black Hole in Ultra-luminous X-ray Sources If intermediate mass black holes (IMBHs) with ~1000 Msolar exist or not is one of the biggest questions in the modern astrophysics. Ultra-luminous X-ray Sources (ULX) are bright compact X-ray sources often found in nearby spiral galaxies. Because their luminosities (10^40-10^42 erg/s) largely exceed the Eddington limits of the Galactic compact objects (10^38 to 10^39 erg/s), ULXs are prime candidates of the IMBHs. Alternatively, they may be massive stellar black holes (< 30 Msolar) shining at super-Eddington luminosities. Unfortunatelly, X-ray observations may not distinguish the two cases. Here, we propose a novel method to constrain the black hole mass in ULXs by measuring the position-velocity (PV) map of the Giant Molecular Clouds (GMCs) surrounding the ULXs. We propose to observe NGC 5408 X-1, which is known to be associated with optical and radio nebulae. If there is a 1000 Msolar black hole in the center, we will see a significant increase of the rotational velocity of the GMC toward the central black hole. This is measurable with the Cycle 3 nominal performance, and the cases with ~1000 Msolar black hole and ~30 Msolar black hole are clearly distinguished. Black holes Stars and stellar evolution 2017-11-22T04:53:30.000
552 2018.1.00500.S 64 Testing the Cometary Origin Scenario in a Young, Gas-bearing, Beta Pictoris Analogue Comets in the young Solar System played a key role in the delivery of volatiles, including water, into the Earth's young atmosphere. At least 3 debris disk systems, including the archetype beta Pic, exhibit confirmed evidence for gas production via cometary activity. Models of their gas can provide important clues on the volatile composition of exocomets, and by inference on the atmospheres of the exoplanets they will enrich. The archetype beta Pictoris debris stands out as the best studied debris disk system with exocometary gas. We have developed a model that can consistently explain its low gas mass and dust luminosities in the frame of colliding, volatile-rich bodies. Can this model explain the origin of gas found in other debris disk systems ? We have recently discovered a young debris disk, that harbours beta Pic-like amounts of dust and gas in mm emission, as well as variable circumstellar absorption in the optical, strongly suggesting that exocometary activity is ongoing. We propose to acquire Bands 6 & 7 images of the dust and gas at 0.2 arcsec resolution to obtain key diagnostics needed to constrain the general case of the exocometary origin of the gas. Debris disks Disks and planet formation 2020-10-03T03:29:01.000
553 2016.1.00050.S 2 Solar Chromospheric Heating We aim to constrain the heating mechanisms in both the quiet solar chromosphere and the plage chromosphere by obtaining coordinated ALMA and IRIS observations and comparing those with synthetic observations of advanced numerical models of the chromosphere. The dominant heating mechanisms in the solar chromosphere remain poorly known, in part because of the complex diagnostics that are often difficult to interpret. The availability of ALMA observations, with their linear dependence on temperature, combined with IRIS observations of Mg II h and k lines promises to provide new insights into the coolest parts of the chromosphere and the magnetically dominated chromosphere in plage. In particular we will focus on understanding the importance of the interactions between ions and neutrals and the ambipolar diffusion resulting from these interactions which dissipates magnetic energy and which our models predict plays an important role in the energy balance of both regions. We will use two time series with one pointing that includes internetwork and plage of 1 hour long, one in band 3 and one in band 6, in coordination with IRIS and Hinode/SP observations to address our science goals. The Sun Sun 2017-07-05T00:00:00.000
554 2019.1.00177.S 10 The dusty disk in the Red Rectangle Disks rotating around post-AGB stars should play a fundamental role in the late stellar evolution, yet they remain poorly studied. Only a few post-AGB disks have been well mapped in CO emission, with resolutions of 0.2-0.5". The general structure of the gas-phase component was studied, but the dust mm-wave continuum emission was hardly resolved. In the best studied source, the Red Rectangle, the disk diameter in the continuum is ~ 2", with a dominant component of about 0.2" and a a disk width ~ 40-200 mas. Post-AGB disks have been also imaged in the NIR, which only probe the hottest dust emission in the disk inner rim, with diameters ~ 40 mas. We propose high-resolution continuum mapping in three ALMA bands of the Red Rectangle, whose disk is extended and seen edge-on; some strong lines will be simultaneously observed to better compare the gasoues and dusty components. ALMA can accurately map those emissions with 15-30 mas resolution. Such data will reveal features relevant to understand the nature and evolution of post-AGB disks, like the disk width and flaring, the latitude stratification of the grain temperature and size, and the molecule depletion in the central disk regions. Post-AGB stars Stars and stellar evolution 2022-08-10T17:09:07.000
555 2017.1.01694.S 78 A dense molecular gas survey at high redshift The properties of the dense molecular gas (which traces the places where star formation takes place) have been largely studied in the local Universe. However, only a few studies have aimed at understanding the dense molecular gas at high redshift, most of them based on AGNs and QSOs. Building up on the results from a previous ALMA pilot project (Oteo et al. 2017), we here propose to carry out a dense molecular gas survey by targeting the J=4-3 HCN, HCO+ and HNC transitions in a statistically-significant sample of 17 star-forming-dominated, lensed (U)LIRGs at 1.3 < z < 3.3 selected from the H-ATLAS survey. This is the full sample of lensed high-redshift SMGs from H-ATLAS that can be observed in the same J->J-1 transitions, and arguably the best sample to do the proposed studies (unlensed high-z samples would require very long integration times). Combined with previous data (including CO, [CI], [CII] and water transitions), the proposed observations will allow us to carry out the first systematic study of the dense molecular gas and the properties of star formation at high redshift. Surveys of galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Galaxy evolution 2019-04-28T10:02:36.000
556 2012.1.00139.S 50 Nuclear Continuum Spectra of nearby low-luminosity AGNs We propose point source photometry for ten nearby low-luminosity AGNs at ten frequencies in the band-3, 6, and 7 to obtain continuum spectra for understanding accretion and outflow phenomena in scales of about 10 Schwarzschild radius, in advance of a future submm VLBI. The execution time is 1.3 hr in total. Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei Active galaxies 2017-01-29T19:48:31.000
557 2012.1.00046.S 1 First Direct Measurement of Disk Radius of a Young Brown Dwarf Up to now, more than 1,000 nearby brown dwarfs have been discovered and our understanding of physical properties of brown dwarfs has greatly been improved. The disk radius of young brown dwarfs is a fundamental parameter to study their formation mechanism as well as the onset of planet formation around these objects. A lot of work on disk modeling has been done to estimate disk radii of young brown dwarfs, however no direct measurement of disk radius of any brown dwarfs has been carried out so far. In this proposal, we propose to directly measure the disk radius of ISO-Oph 102, a young brown dwarf of 60 Jupiter mass in rho Ophiuchi. Outflows, jets and ionized winds ISM and star formation 2015-09-16T19:22:38.000
558 2016.1.01338.S 81 Flowing the gas from molecular clouds to protostellar envelopes The formation and evolution of cores and envelopes (and the disks and protostars inside) depend on the density and velocity structure of their parent cloud or filament. The scales of the outer envelope/core (~10^4 AU) are particularly important as the gas properties on these scales influence the mass reservoir (and final mass) of the forming star, and the number of companions in a multiple system. We propose to conduct mosaic observations of a very young mini-cluster in a filament in Orion, representative of the way most stars form in our Galaxy. We will map the cluster using molecular lines that probe different regimes in the star formation environment in order to: 1) characterize the dynamical state and structure of the gas in a region of clustered star formation in a filament; 2) follow the kinematics and distribution of the gas from cloud to envelope scales (~0.1 pc to 1000 AU) in a cluster and study how these impact the multiplicity and disk properties of protostellar systems; 3) investigate how the feedback and gravity of a source affect nearby sources and the cluster medium; and 4) determine how these properties vary between sources at different ages within the cluster. Low-mass star formation ISM and star formation 2019-05-11T00:00:00.000
559 2015.1.00615.S 39 Revealing the disk rotation curve around an O-type YSO Searching for massive rotating disks around early B-type and O-type young stellar objects (YSOs) is a key study to asses the main physical processes of massive star formation. Here, we propose to characterize for the first time the gas dynamics around an O-type YSO, unveiling the presence of a massive disk and determining its rotation curve, by means of high-resolution (0.2") and sensitive ALMA observations in Band 6 toward G23.01-00.41. This star forming site harbors a known hot molecular core (HMC) that we have recently studied in detail through both, SMA observations in the 230 GHz band (with an angular resolution of ca. 1"), and with VLBI multi-epoch observations of strong water and methanol masers. The outcome of these studies has unveiled a massive and flattened HMC, rotating about an O-type YSO with a dynamical mass of 19 Msun, which powers a well-collimated bipolar outflow at the sub-parsec scale. With this is mind, we want to observe the CH3CN(12_K-11_K) line emission and dust continuum at 1 mm to accurately trace the velocity field of hot and dense gas inside the HMC and to study the spatial morphology of both gas and dust emission. Disks around high-mass stars Disks and planet formation 2018-01-28T13:57:40.000
560 2019.1.00019.S 44 Measuring Central Black Hole Masses in Low-mass Galaxies We observed seven nearby (D<20 Mpc) low-mass (M* < 10 billion solar masses) galaxies in ALMA Cycle-5 to enable more robust detections and dynamical mass measurements of ~10^6 Msun mass central black holes. These measurements will provide constraints on the formation of black holes in the early universe, and on the physics underlying galaxy-black hole scaling relations. Our target galaxies were chosen across the Hubble sequence and based on the presence of molecular gas from single dish surveys. The high-resolution observations of ALMA clearly detected evidence of nuclear rotating molecular disks, which are so called circumnuclear gas disks (CNDs), surrounding their black holes of five targets, and two of them are of sufficient quality to measure their black hole masses. In two other galaxies, the detected gas was not in rotating disks, necessary to derive black hole masses. For the last three galaxies, unfortunately, we are lacking short baselines in the data obtained. Here we propose to use ALMA to obtain intermediate resolution observations of these three targets. A small amount of additional time is needed to maximize the already invested ALMA time. Galactic centres/nuclei Active galaxies 2021-01-09T13:49:29.000
561 2018.1.00781.S 29 A magnified view of the cradle of globular clusters at z>6 We propose deep ALMA observations of the central, strongly magnified central multi-image of a giant Ly-alpha nebula which contains two globular cluster precursors (GCPs) at redshift >6. We will detect the 2P3/2-2P1/2 [CII] transition, one dominant neutral gas coolant. The systems embedded within the nebula are among the faintest spectroscopically confirmed star-forming sources at high redshift, have typical instrinsic sizes of 10-20 pc, UV magnitudes >~30 and SFR surface densities greater than 300 Msun/yr/kpc^2. Through band 6 observations with 0.5" FWHM resolution (probing delensed ~200 pc at z~6), we aim at tracing the distribution of the neutral gas in (and around) the two compact systems. According to our estimates, ~3 hr of ALMA time will be enough to detect [CII] and to: 1) assess the morphology of the neutral gas distribution around the two clusters. Coupled to extant Ly-alpha data, this will allow us to establish the presence of the cold gas which fuels star formation; 2) constrain the gas consumption timescale and, therefore, the duration of the SF event of our objects. Such pieces of information will open a new path to multiwavength studies of GCPs at high z. Lyman Alpha Emitters/Blobs (LAE/LAB), Gravitational lenses Galaxy evolution 2020-09-04T11:47:32.000
562 2013.1.00116.S 0 How Strongly are the 2 Known Class 0 Disks Magnetized? To date only 2 Class 0 objects have well detected, ~100 AU Keplerian circumstellar disks: L1527 and VLA 1623. Other sources with similar or better resolution observations do not exhibit clear Keplerian disks, e.g. L1157, down to 10 AU scale. What is the difference in these two populations? Although a very small sample so far, there is an interesting trend. The sources with 100 AU disks have inferred magnetic fields nearly perpendicular to their disk rotation axis, and the sources without detected 100 AU disks have magnetic fields nearly aligned with their outflow axis (a proxy for the rotation axis). This is suggested by many current theoretical simulations as magnetic braking reduces the angular momentum of material falling onto the disk, resulting in a smaller circumstellar disk: 10 AU or less compared to 100 AU. In this proposal, we request time to measure the dust continuum polarization in the 2 known 100 AU Class 0 disk systems at a resolution of 50 AU. With the ability to constrain the inferred morphology and magnetic field strength in the systems, we will make better theoretical models to investigate magnetic braking and the early disk formation and evolution. Disks around low-mass stars Disks and planet formation 2017-01-25T22:32:32.000
563 2015.A.00019.S 9 ALMA observations of a possible counterpart to the high-energy neutrino event IceCube 160427A We propose for Directors Discretionary Time to search for millimeter emission from a recently discovered Type 1c supernova that appears to be a source of neutrinos but is quenched in gamma- and X-rays. Such objects, never before seen, are a possible source of the mysterious high-energy neutrino background. These ALMA observations, in tandem with the VLA and other resources, will provide essential information on the physical nature of the source and are time critical. Gamma Ray Bursts (GRB) Cosmology 2017-01-21T20:47:30.000
564 2019.1.00843.S 143 The effects of feedback on molecular gas: Survey of CO in 30 Doradus We propose a molecular gas survey of the 30 Doradus region to understand how massive star feedback affects the physics of star formation in the neighboring molecular gas. Our survey covers the most prominent CO-emitting regions within 60pc of the the R136 super star cluster. Abundant ancillary data makes 30 Dor the best studied case of extreme star formation at reduced metallicity, which may dominate star formation processes at higher redshift. The pre-main sequence (PMS) stars from our HST studies and the young stellar objects (YSOs) from our Spitzer and Herschel studies provide a ~2" map of star formation activity spanning the stellar initial mass range. With ALMA, we will map molecular gas with 12CO, 13CO, C18O J=2-1 and H2CO at a comparable angular resolution of ~1.8", to (1) measure the effect of the feedback environment on star formation triggering, activity, and thresholds, and (2) measure the degree to which feedback energy is directly transmitted into the turbulence of the molecular clouds. Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds ISM and star formation 2021-03-31T23:04:26.000
565 2021.1.00576.S 23 Pushing the frontier with ALMA: star formation at sub-kpc scale in distant radio-loud AGN hosts Powerful AGN near Cosmic Noon are tracers of active AGN feedback and massive galaxy formation. In particular, the population of high-redshift radio galaxies (HzRG) are the only objects in which quasar-mode feedback, radio-mode feedback and an active massive galaxy build can be observed simultaneously. We will use ALMA to observe the [CII] line + dust continuum in a sample of HzRG at z~3.5, tracing at sub-kpc scales both the young stellar population and cold gas. The sample has exquisite supporting data with MUSE, SINFONI, Spitzer, Herschel and has been approved for JWST Cycle 1. Despite this wealth of supporting data, the questions of how and where these massive galaxies form their stars and how the powerful AGN is triggered remain. At a resolution of 0.1arcsec with ALMA, we will map the cold dust distribution, informing us how star formation is connected to the AGN- and jet-driven outflows. The [CII] kinematics will enable us to disentangle outflows/mergers signatures and relate it to the ionised gas kinematics from JWST data. We will address the long-standing question how AGN activity, massive galaxy build-up, merger activity and environment are connected at and near Cosmic Noon. Active Galactic Nuclei (AGN)/Quasars (QSO), Early-type galaxies Active galaxies 2023-12-19T14:02:17.000
566 2016.1.00627.S 16 Chemical evolution during the disk life cycle The volatile compositions of planets, including water and organic reservoirs, are set by ice and gas compositions in protoplanetary disks. These compositions evolve with time due to a combination of time dependent chemistry and sequential lock-up of elements into icy boulders. As a consequence, the division of O, C and N between ice and gas may change dramatically between disk formation in embedded protostars and the time of disk gas dispersal ~5Myrs later. We propose to explore the time dependent disk chemistry, including the sequential removal of O, C, and N from the gas, through a systematic survey of O, C and N bearing molecules in 15 disks of different ages. The disk sample is drawn from nearby star forming regions Serpens, Taurus and Upper Sco, and contain protostellar disks, young and old protoplanetary disks. The survey will directly address the prevalence of substantial volatile depletion during planet formation, and at what timescales different elements are sequestered out of the gas-phase and into icy solids. The survey will thus provide initial conditions for planet formation throughout the lifetimes of protoplanetary disks. Disks around low-mass stars Disks and planet formation 2018-05-17T23:39:33.000
567 2019.1.00151.S 14 Molecular and atomic gas in a z=2.5 X-ray cluster: examining star formation and environment in the early universe We will undertake a case study of molecular and atomic gas in the most distant X-ray cluster core known at z=2.5. With a single pointing and two spectral tunings, we will detect 34 lines including neutral carbon, CO, and H2O in seven core member galaxies, along with Rayleigh-Jeans dust continuum. Combined with previous low-J CO observations, these will allow us to estimate star formation densities, calibrate alphaCO, look for the influence of shocks in gas heating, and, more broadly, compare gas conditions within these early universe cluster core galaxies to conditions in more familiar local systems. The results will yield insight into the fate of these galaxies and the effects of the cluster environment at z~2.5. Galaxy structure & evolution, Galaxy Clusters Galaxy evolution 2021-06-23T16:23:49.000
568 2017.1.00053.S 30 Are Close Binaries Formed Through Disk Fragmentation? Binary and multiple star formation is a common outcome of the star formation process, likely occuring at early times. To characterize the multiplicity frequency versus separation, we have conducted a VLA 8mm survey of all protostars (N~80) in the Perseus molecular cloud (d=230pc) at 0.065" (15 AU) resolution, identifying 18 proto-binary systems with separations between 18.5 and 440 AU. However, the VLA data alone do not directly constrain the formation scenarios of these close multiples, which are likely either disk fragmentation or turbulent fragmentation with dynamical evolution. We can discern between disk and turbulent fragmentation by characterizing the environments around the multiple systems. Therefore, we propose for ALMA observations of dust continuum and molecular line emission in C18O, 13CO, and 12CO toward 12 of the 18 close multiples. With these observations, we will identify rotationally-supported circumbinary disks, aligned or misaligned outflows, and relative source velocities that will reveal the origins of these systems. This sample is large enough to reveal whether or not close multiples typically form via disk fragmentation or turbulent fragmentation. Low-mass star formation ISM and star formation 2019-12-12T19:04:01.000
569 2019.2.00129.S 10 Assessing the impact of AGN feedback in the prototypical Seyfert 2 galaxy NGC 1068 NGC 1068 is the prototype of Seyfert 2 galaxies and one of the best-studied galaxies in the local Universe. High-resolution ALMA mapping of the central kpc has revealed strong AGN feedback effects, including a molecular gas outflow out to R~400pc. However, optical observations clearly demonstrate that AGN feedback extends further out, with two prominent ionisation cones that graze the disc and reach scales of 10 kpc. We propose to map CO(2-1) at 5.7" ~ 400pc resolution across the disc of NGC 1068 to measure the large-scale impact of the AGN. We will study whether molecular gas properties change inside the ionisation cones with respect to the rest of the disc and relative to other non-active galaxies. Combining with existing sub-arcsecond ALMA data, we will construct a high-resolution cube of the central area which is sensitive to all spatial scales, bridging the gap between AGN effects in the nuclear region and surroundings. Outflows, jets, feedback, Giant Molecular Clouds (GMC) properties Active galaxies 2021-04-08T18:35:30.000
570 2016.1.00248.S 32 Are Sub-virial Cores in IRDC G28.34 Supported by Magnetic Fields? Massive stars form mostly in parsec-scale molecular clumps that collapse and fragment to spawn a cluster of stars. The current scenarios of massive star formation range from a relatively slow formation in which massive cores evolve in a quasi-static equilibrium supported by turbulence and magnetic fields, to fast formation in which clouds collapse in one dynamic time. The two scenarios can be examined through detailed equilibrium analysis including gravity, turbulence and magnetic fields. We propose to obtain dust polarization of three infrared-dark-cloud clumps G28.34 MM1/MM4/MM9 to investigate magnetic support in dense cores. The three clumps contain 500 - 1000 Msun each, sufficient to form massive stars, and show significant fragmentation when observed with the SMA and ALMA. Analysis found that the mass in the clumps and cores far exceeds their respective virial mass from turbulence. This ALMA observation will map the magnetic field configuration and determine magnetic field strength using statistics methods. Such a study can only be carried out with ALMA thanks to its sensitivity, and is vital to developing theoretical models on massive star formation. High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2019-06-28T14:44:10.000
571 2016.1.00004.S 5 Resolving extended atmospheres of evolved stars: chromospheres and convection Although processes like stellar activity and convenction can have a major impact on the circumstellar chemistry and chemical yields of evolved stars, the surface and extended atmosphere studies of these stars have so far been limited to the visual to near-infrared wavelength ranges, with limited imaging capabilities, or the marginal resolving power offered at radio wavelengths. Using ALMA long baselines, we have been able to resolve the details of the stellar atmosphere of Mira. This has demonstrated the unique capability of ALMA to study the surface structure and activity of AGB stars. Here we propose to map the stellar disk structure of four of the closest AGB stars in order to map their extended atmospheres and determine the presence of magnetic or convective activity at unprecedented resolution. Such observations, possible now for the first time, are crucial for modeling the structure of AGB atmospheres from radio- to optical wavelengths. Asymptotic Giant Branch (AGB) stars Stars and stellar evolution 2018-10-20T16:14:52.000
572 2017.1.00856.S 32 [CI] as a gas tracer in main sequence star-forming galaxies at z~2 Most of our knowledge about the gas content of galaxies in the early Universe comes from observations of the traditational tracer molecule, 12CO. However, there are several reasons to expect that 12CO is a very inefficient gas tracer in the star-forming, metal-poor environments within the ISM of high-z galaxies, which may have led to the gas content of high-z galaxies being systematically underestimated. We propose to observe the [CI](^3P1 - ^3P0) fine structure line (rest frequency 492 GHz) in a sample of seven main-sequence star-forming galaxies at z~2. This line is a more effective tracer of the cold molecular ISM, which is free of many of the biases that affect traditional gas tracers (i.e., 12CO). While observations of [CI] as a gas tracer to date have been promising, most galaxies observed in [CI] are extreme starburst galaxies not representative of the star-forming population as a whole. Our proposed observations of [CI] in a sample of 'normal' star-forming galaxies at cosmic noon are a vital first step in developing our understanding of [CI] as an improved tracer of gas in the early Universe. Surveys of galaxies Galaxy evolution 2019-07-18T12:14:09.000
573 2019.1.00129.S 6 Investigating the Multi-Phase ISM in SDP.11 at z ~ 1.8: Gas Physics on Sub-kpc Scales Using Gravitational Lensing We propose a detailed study of the ionized, atomic, and molecular gas in SDP.11, a gravitationally lensed, high-z, Ultra-Luminous Infrared Galaxy (ULIRG) analog, at z=1.783. The combination of this fortuitous lensing configuration and redshift allow us to map the [CI] 609 um, [CI] 370 um, CO(4-3), CO(7-6), and [NII] 122 um lines with ALMA, at sub-kiloparsec resolution. These lines, combined with our existing [CII] ALMA observations, ionized gas lines from Herschel, and multi-band radio free-free emission data, will allow us to estimate the ambient stellar UV radiation field strength, PDR gas densities, molecular gas density, temperature and mass, dust mass and temperature, and absolute [N/H] abundances, at sub-kiloparsec resolution across the source, as well as to determine the source-averaged stellar radiation field hardness. By probing the gas physics of SDP.11 in all phases of the ISM, ionized, atomic, and molecular, we will learn more about the ways in which massive galaxies rapidly produced their stars near the peak of the cosmic star formation history. Starburst galaxies, Gravitational lenses Active galaxies 2022-06-17T21:19:36.000
574 2013.1.00212.S 8 Detailed molecular gas distribution of an active star forming region within a low-metallicity environment: CO/CI observations of N83 in the Small Magellanic Cloud (SMC) The aim of this observation is to reveal for the first time the detailed molecular gas distribution of an active star forming region within a low-metallicity environment to understand the formation and structure of GMCs as well as the star-formation process at low metalicity. We propose mosaic observations toward a molecular clump associated with the active star forming region N83 in the SMC in the J=2-1, 3-2 lines of 12CO and 13CO, and [CI] with a final angular resolution of 1.5 arcsec, corresponding to a spatial resolution of 0.44 pc. CO observations will be used to precisely determine the density and temperature of the gas, and in combination with the velocity information, we can investigate the dynamics of hot-dense molecular clumps associated with HII regions and cold-dense molecular clumps prior to massive star formation. [CI] line is also another important probe to reveal the distribution of molecular gas without CO emission, being a significant mass component of the cloud, affecting the system's self-gravity and providing an additional supply of gas to fuel star formation, and also a key to understand the variations of the CO-to-H2 conversion factor. Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds ISM and star formation 2016-12-15T04:18:48.000
575 2017.1.01460.S 71 Probing transitional disks with a gap of the Solar-system's planetary orbital radii We propose band 6 observations (including dust continuum, the J=2-1 transitions of 12CO, 13CO, and C18O) at a spatial resolution of 0.03 arcsec of three transitional disk systems. Our targets have relatively small gaps with r<0.15 arcsec corresponding to r<20AU at typical star forming regions, and similar orbital radii of Uranus/Neptune in our Solar system. Hence, probing transitional disks with a relatively small gap could guide our understanding of planet formation of giant planets in our Solar system. With a high spatial resolution of 0.03 arcsec, our proposed observations enable us to look for and examine fine structures such as multi-gaps, asymmetries, inner disks and streamers. By comparing our results with literature studies of transitional disks with a relatively large gap at r>0.3 arcsec, we could test whether the size of gap is a critical parameter in determining disk sub-structures. By comparing our results with literature studies of transitional disks with a relatively large gap of r>0.3 arcsec, we could test whether the size of gap is a critical parameter in determining disk sub-structures. As by-products, we will study CO gas disks as well. Disks around low-mass stars Disks and planet formation 2018-11-30T22:47:25.000
576 2013.1.00403.S 3 Sub-Arcsec Molecular Gas Imaging of the z=2.8 Submillimeter Galaxy SMM J02399-0136 We propose sub-arcsec imaging of the molecular gas in the z=2.8 submillimeter galaxy (SMG) SMM J02399-0136, the very first SMG discovered with a confirmed counterpart. This remarkable system is a merger of two hyper-luminous infrared sources with AGN feedback that appears to be enhancing the star-formation activity in the system. We request Band-3 and Band-6 imaging observations with a resolution of 0.45" (~1.5 kpc in the source frame), which is sufficient to distinguish between the various components of the system and to study the possible interaction of the QSO with the red starburst region as well as the surrounding large blue Ly-alpha cloud. We propose to observe the CO(3-2), HCN(4-3), HCO+(4-3), CO(7-6), and [CI] spectral lines to determine the molecular gas mass, gas excitation, kinematics, dense-gas fraction, and star-formation efficiencies of the system. The 3.3 mm and 1.3 mm continuum observations when combined with the archival ALMA Band-9 data will reveal the distribution of the dust mass associated with the various components. Sub-mm Galaxies (SMG) Galaxy evolution 2015-08-19T18:23:52.000
577 2016.1.00236.T 140 Unlensed HyLIRG systems from the South Pole Telescope 2500deg^2 survey From a 2500 degree^2 survey, the South Pole Telescope (SPT) has detected at 1.4mm, ~100 bright high redshift star forming galaxies. Most of these are strongly lensed ULIRGs, however three are candidates for unlensed, extreme hyper-luminous galaxies. We propose to map these systems in ISM diagnostic lines, resolving and detecting all known continuum components. With redshifts of z=4.2, 4.3, 5.7, we can efficiently obtain band6/7 C+/N+ measurements, along with deep mid-J CO. They represent the record holders for the most luminous systems in the Universe (S850~60mJy in the LABOCA beam). Our observations will characterize these systems, going well beyond the ALMA subcomponents already detected in a Band-7 mapping program. Our main scientific goals are (1) detect all subcomponents in continuum and CO which make up the single dish fluxes, (2) constrain the ISM metallicity through the C+/N+ line ratio. (3) further elucidate the `proto-cluster' aspect of these systems by searching for lines from additional faint S850~1-2mJy sources identified in the Band-7 imaging (and beyond), if they lie at the same redshifts, completely characterizing these systems in molecular gas. Starburst galaxies, Sub-mm Galaxies (SMG) Active galaxies 2018-04-22T04:25:16.000
578 2016.1.00372.S 211 Complete Census of Bright Lensed Submillimeter Galaxies Discovered by the Herschel Lensing Survey To discover exceptionally bright cluster-lensed submillimeter galaxies (SMGs) like the Cosmic Eyelash, our team has been conducting a large Herschel survey of gravitationally lensed galaxies in the fields of massive galaxy clusters: The Herschel Lensing Survey (HLS) (PI: Egami). The HLS has obtained deep PACS (100/160 um) and SPIRE (250/350/500 um) images of 54 massive galaxy clusters as well as shallower (but nearly confusion-limited) SPIRE images of 527 clusters with a total observing time of ~420 hours. Now completed, the HLS has identified a number of exceptionally bright Herschel sources that are likely lensed SMGs at z>1. Here, we propose to obtain high-resolution (beam=0.2'') ALMA dust continuum images (at 1.3mm) of the 21 HLS sources, which represent the brightest of the sample. ALMA high-resolution images are essential for, (1) identifying the counterparts and lensing geometry, (2) examining the relation between the dust continuum sources and the stellar continuum sources detected at shorter wavelengths, and (3) probing the physical properties of individual star-forming regions at the sub-kpc scale through the reconstruction of the source-plane image. Sub-mm Galaxies (SMG), Gravitational lenses Galaxy evolution 2018-06-23T23:36:20.000
579 2021.1.00024.S 3053 A Legacy Survey of SMGs in the CDF-S We propose ALMA linescans for a complete sample of 51 S(850um)>2.25mJy SMGs from an extremely deep SCUBA-2 CDF-S map, all with accurate positions/fluxes from prior band 7 ALMA imaging. The scans will detect 2+ bright CO transitions in the majority of SMGs, establishing firm redshifts (unlocking great potential for individual and stacked spectral constraints from radio to X-ray), robust molecular gas (mass, excitation curves, kinematics, t_depl) and dust properties (mass, temperature) estimates. These precise physical constraints, which are unattainable by UV/opt/NIR methods, will advance our understanding of star formation in this critical flux regime, which accounts for 30% of the 850um background. The samples completeness and the unsurpassed ancillary data in the central CDF-S (deepest Chandra, Herschel, HST NIR/optical, and soon JWST) make it a unique legacy dataset for understanding typical SMGs. Sub-mm Galaxies (SMG) Galaxy evolution 2023-06-24T02:01:57.000
580 2019.1.00092.S 49 What lines trace which processes in the CMZ? The Central Molecular Zone (CMZ) of our Galaxy is bright in many lines that are usually limited to hot protostellar cores in other parts of the Galaxy. These abundant molecular lines may tell us a great deal about protostellar cores, outflows, shocks, and general gas properties, but at the moment, we do not know which lines are associated with different physical processes. A reference survey showing which lines are excited and where they are excited is needed to interpret existing CMZ observations, to plan future observations, and to enable comparison between our CMZ and the centers of other galaxies. We propose a blind, complete spectral line survey covering bands 3-7 of a single pointing in the CMZ to determine which lines can be used to trace: (1) protostellar cores, (2) turbulent shocks, (3) diffuse and quiescent molecular gas, and (4) protostellar outflows in the CMZ. We will run this program as a legacy survey, releasing data immediately, and we will produce data products that will inform ongoing and future CMZ programs. Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2021-06-10T22:16:16.000
581 2011.0.00957.S 0 The ALMA-SPT Redshift Survey Recent ground and space-based multiwavength (sub)millimeter surveys covering hundreds of square degrees have discovered a large number of strongly lensed, ultra-bright submm galaxies (SMGs). The largest of these, by nearly an order of magnitude at present, is the South Pole Telescope (SPT) survey, which covers 1300 square degrees. The unparalleled SPT sky area makes it the survey most adept at locating the 'brightest of the brightest' of this new population. Its 1.4mm detection wavelength ensures a uniform source selection function across z=1-8. Both aspects make SPT the ideal survey to uncover substantial numbers of the elusive z>4 SMG population. We are carrying out a major multi-wavelength (optical to mm) observating campaign aimed at characterizing the SPT sources in terms dust/gas content, star-formation rates and stellar masses. The most urgently missing information are the redshifts. With the advent of ALMA, even in the early science configuration, unbiased redshift searches for these bright high-z sources are possible in a revolutionary small amount time (3-4 redshifts per hour even in moderate observing conditions). We propose to observe the 26 brightest SMGs selected from the SPT survey. Our proposed observations are designed to obtain unambiguous and unbiased redshifts out to z=6, and as such will sample the high redshift tail of SMGs for the first time. Sub-mm Galaxies (SMG), Gravitational lenses Galaxy evolution 2013-04-25T07:42:09.000
582 2013.1.01397.S 2 Measuring Velocity Structure of MHD Wind from a Protoplanetary Disk We propose to observe line transitions of CI, CN and 13CO at bands 7 and 8 with high velocity resolution and high sensitivity in order to measure velocity structure of the MHD wind from a protoplanetary disk around TW Hya. Recent MHD simulations suggest that angular momentum transfer and mass accretion in the disk surface will be induced by magnetocentrifugal wind rather than magnetorotational instability. Our observations of a disk wind will give us information on mass accretion mechanisms, which is essential to understand gas dispersal from the disk and then planet formation processes. The wind velocity is not easy to measure since it is small compared with the Keplerian rotation velocity. Here we propose to detect the disk wind velocity, using PDR species (CI and CN) as disk wind tracers and 13CO as a tracer of Keplerian rotation. The difference in the maps of intensity weighted velocity field between the lines give us clear evidence of the disk wind. In addition, the difference in the maps of intensity weighted velocity dispersion will show the radial distribution of wind velocity and give us information of how angular momentum transfer is controlled in the disk surface. Disks around low-mass stars Disks and planet formation 2016-07-14T07:56:35.000
583 2019.1.00315.S 6 The Bursting Massive Young Stellar Object S255 IR Temporal photometric variations associated with young low-mass stars of Class 0, I, and II have been observed. It is conceivable that similar burst phenomena occur in the massive star formation process. Indeed, on the theoretical front, 3D numerical radiation hydrodynamic simulations yield variable accretion events in high mass star formation. Observational evidence in favour of episodic bursts in the high-mass domain also grows steadily in the recent years - two massive young stellar objects, S255IR SMA1/NIRS3 and NGC6334 I, exhibit submillimeter luminosity bursts. For further understanding the flaring events, it is indispensable is to take advantage of such rare objects at their unique varying phase with follow-up observations. To this end, we propose sensitive ALMA observations at Band 7 with two key science goals: (1) measuring its temporal variation in dust continuum and molecular line emission, and (2) imaging at the highest angular resolution the disk sub-structures (arms, clumps). With ALMA's exquisite sensitivity and resolution, the proposed program will in great detail characterize the burst history and reveal the underlying structure of the S255IR SMA1/NIRS3. High-mass star formation ISM and star formation 2022-08-23T23:26:57.000
584 2013.1.00218.S 12 Spatially resolved 3 mm imaging line survey toward NGC 7469 We propose to conduct a line survey toward the central kpc region of the nearby type-1 Seyfert galaxy, NGC 7469, at 3 mm wavelength. This observation will be combined with our accepted cycle 1 program toward the same region, to fully cover 86-116 GHz range. From this observation, we will investigate the effect of AGN and starburst activity on the molecular materials. For example, we focus on the abundance variation of (1) HCN and CN, which are expected to be enhanced in AGNs, (2) molecules sensitive to UV radiation such as HNCO, which can be used to probe the phase of starburst activity, and (3) dust-related molecules such as SO, CH3OH, SiO, CH3CN, to investigate their properties especially in AGNs. All observed properties will be compared with chemical models and results of our ALMA cycle 0/1 programs toward NGC 1097, 253, and 1068, to further investigate the effect of AGN and starburst on molecular properties. In addition, NGC 7469 hosts a bright type-1 AGN whose Eddington ratio is comparable to QSOs. Therefore, this observation can also serve as a local template of molecular properties for exploring high-redshift QSOs in future ALMA cycles. Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) ISM and star formation 2016-11-13T18:01:18.000
585 2011.0.00013.SV 0 Science verification observation of Juno Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. Solar system - Asteroids Solar system 2016-06-24T14:02:07.000
586 2019.1.01148.S 18 Where's the dust? 870um in Strongly Lensed z~2 Normal Galaxies We propose to observe six z~2 gravitationally-lensed "normal"/Main Sequence galaxies selected from Saintonge et al. (2013) and Dessauges-Zavadsky et al. (2015) at 870um in order to determine the location of the dust emission. So far, Tadaki et al. (2017) has published the largest sample of resolved dust observations of z~2 Main Sequence galaxies, and found uniformly compact dust emission suggestive of compact star formation growing a central bulge. However, strongly lensed Main Sequence galaxies at similar redhsift have shown much more extended dust emission that traces the UV and stellar mass. By undertaking deep 1" resolution observations of a sample with known IR SEDs, we hope to better understand the prevalence of extended low surface brightness dust emission in "normal" z~2 galaxies. In addition, due to the fact that the proposed sample is lensed, even at this modest resolution we will also be able to address the spatially resolved Schmidt-Kennciutt relation and whether patchy obscuration drives variation in the IRX-beta relation. Lyman Break Galaxies (LBG), Gravitational lenses Galaxy evolution 2021-04-21T20:37:35.000
587 2015.1.01452.S 197 CO spectral scanning of z>6.5 QSO candidates selected from PanSTARRS We propose ALMA spectroscopy of 23 QSO candidates at z>6.5 selected from the new PanSTARRS1 3pi survey. Our goal is to build a statistical sample of z> 6.5 QSOs, which is crucial for understanding of the reionization epoch and growth of the supermassive black holes in the early Universe. All targets are clear z-band dropouts (detectable only in the y band) with faint/no detection in WISE. This makes them very promising high-redshift QSO candidates. We propose a new and more efficient spectroscopic survey, by spectral scanning CO(6-5) emission in ALMA Band 3. The redshifted CO(6-5) line is between 84 and 92 GHz. Therefore, we only need two tunings to scan the CO line at 6.5 High-z Active Galactic Nuclei (AGN) Active galaxies 2018-03-06T14:00:34.000
588 2017.1.00930.S 30 Evolution of Molecular Gas Excitation from Starbursting to Quiescence The bimodality of star-forming vs. quiescent galaxies is driven by a bimodality in gas content. Post-starburst galaxies are experiencing a transition from star-bursting to quiescence, not only in their stellar populations but also in their molecular gas properties. Our work has revealed that molecular gas can remain after a starburst has ended, with depletion occurring during the post-starburst phase. Our next step is to study when the excitation state of the gas changes from the high excitation states seen in starbursting galaxies to the low excitation state seen in quiescent early type galaxies. We propose to observe the CO (3--2) emission spatially resolved across four post-starburst galaxies, to determine if evolution in the CO spectral line energy distribution occurs before, during, or after the post-starburst phase. These results will inform how the gas depletion mechanism affects the state of the gas as it is depleted. Starbursts, star formation, Merging and interacting galaxies Active galaxies 2019-09-21T21:59:41.000
589 2017.1.01174.S 248 Directly linking gas and ice abundances in low-mass protostars The main scientific goal of this proposal is to test observationally whether complex molecules detected in the gas phase originally have been formed by solid-state processes in icy grain mantles, as assumed in most interstellar chemistry models. Comparison of abundance ratios of these molecules obtained with ALMA in hot cores and envelopes with those derived from ice spectra to be obtained with JWST-MIRI GTO data for the same sources offers for the first time the opportunity to actively bridge the gas-grain gap. Low-mass star formation, Astrochemistry ISM and star formation 2020-02-12T13:12:23.000
590 2011.0.00396.S 0 Using the first inteferometer H2D+ observations to constrain clustered star-forming core structure Given that most stars in our galaxy form in clusters, understanding the process of clustered star formation has become a key goal of star formation astronomy. As a dense core collapses, however, the density progression and accompanying temperature changes result in well-documented molecular abundance variations. The consequences of this chemical evolution are twofold: first, we must select molecular tracers carefully for the conditions we are probing; and second, we can use detailed modeling of the structure, chemistry and kinematics of dense cores to determine their evolutionary history and predict their future. The molecular ion H2D+ is likely the best kinematic probe of the dense core gas most actively forming stars. Here, we propose to use the unprecedented sensitivity and resolution of ALMA to probe the kinematics and chemistry of two evolved, star-forming cores using H2D+ and N2H+ to determine observationally for the first time the H2D+ and N2H+ abundance structure across dense cores on scales of ~ 360 AU. Through detailed modeling, these data will provide much-needed constraints to dynamic chemical models of core collapse in clustered environments. Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2013-11-21T16:16:00.000
591 2022.1.00968.S 322 Exception or the Rule? A Survey for Gas in Debris Disks ALMA detections of gas-rich debris disks around A type stars of 10-50 Myr have led to a re-writing of our understanding of late disk evolution. Collisions between planetesimals in debris disks release a second generation of molecular gas that can have a transformative influence on the atmospheres of planets in the system. Although only found in around 20 objects so far, the detection rate of secondary gas in debris disks suggests that this is not an exceptional group, but rather the normal state for debris disks, particularly around A-type stars. We require a large survey to validate the proposed ubiquity of large amounts of molecular gas in systems that have evolved beyond the protoplanetary phase. We request a deep survey of gas and dust in the debris disks of A type stars in Lower Centarus Crux and Upper Centaurus Lupus (15-20 Myr). Our 46 targets + 10 archival objects comprise a nearby, complete sample that is ideal for detecting molecular gas in systems that have evolved from the protoplanetary- to debris- phase. These observations will determine how common this gas-rich phase is around A type debris disks and measure the typical disk masses with which they are present. Debris disks Disks and planet formation 2023-10-18T21:33:02.000
592 2018.1.01172.S 8 Measuring Magnetic Field Morphologies in Disks Using the GK Effect Polarimetric observations and theoretical modeling indicate that we cannot measure the magnetic field morphology in circumstellar disks via (sub)millimeter polarization continuum observations. The Zeeman Effect is also very difficult to observe toward circumstellar disks, and does not provide the plane of sky field morphology. One other promising way to measure the magnetic field morphology in the plane of the sky is via line polarization. The Goldreich-Kylafis (GK) effect suggests that line polarization is perpendicular or parallel to magnetic field direction. We propose to observe line polarization toward the disks IM Lup and HD 142527. These observations will tell us whether the GK effect can measure the magnetic field morphology in disks. Disks around low-mass stars Disks and planet formation 2020-12-12T14:34:09.000
593 2018.1.01577.S 33 Searching for PAHs in the Red Rectangle Polycyclic Aromatic Hydrocarbons (PAHs) are widely accepted as the carriers of the Aromatic Infrared Bands (AIBs), but an unambiguous identification of any specific interstellar PAH is still missing. Here we propose to close this gap and conduct a deep search for the high-J rotational transitions in corranulene (C20H10) - a symmetric, bowl-shape PAH molecule with a large dipole moment (2.07 D). Our selected target is Red Rectangle Nebula, a pre-planetary nebula which is the brightest source of AIBs in the sky and where a previous attempt to detect corranulene was unsuccessful due to limited sensitivity. Astrochemistry ISM and star formation 2020-08-31T10:32:06.000
594 2013.1.01051.S 22 A high-resolution band-7 continuum survey of SMGs in the field of five SZE-selected galaxy clusters. We propose to obtain band-7 continuum mapping at ~1 arcsec spatial resolution for a sample of 39 submillimeter galaxies (SMGs) detected with LABOCA (~18"/beam) in the field of five galaxy clusters originally detected through their Sunyaev-Zel'dovich Effect decrement signals at 148 GHz. The selected targets have 870 micron (345 GHz) flux densities ranging from 3.7 to 36.9 mJy, but our current photometric accuracy is compromised by blending of point source and extended SZE emission, and plausibly of multiple fainter SMGs within a single LABOCA beam. To secure detection of all targets and their possible sub-components at the 4 sigma level, we require a point-source sensitivity of 0.3 mJy. To achieve this observational goal, we require a total observation time of 2.2 hours including overheads. Gravitational lenses, Galaxy Clusters Cosmology 2016-04-10T19:11:56.000
595 2017.1.00478.S 252 Feedback and Star Formation in Extremely Red Quasars Dust-reddened quasars are candidate young objects participating in the early stages of massive galaxy formation. Our team recently discovered a unique population of high-redshift extremely red quasars (ERQs) in SDSS-III/BOSS that has an ensemble of peculiar line properties indicative of powerful outflows, e.g., strong blueshifted broad emission lines, frequent broad absorption lines, and the broadest most blueshifted [OIII] 5007 lines ever reported (reaching 5000 km/s). We propose Band 6 observations of 15 ERQs at redshifts ~2.4 to measure their CO(7-6) and [CI](2-1) emission lines and dust continua (at ~385 microns rest) at 0.63 resolution. Our goals are to 1) characterize the ERQ population compared to star-forming SMGs and other/normal quasars at similar redshifts, 2) test the youth of ERQs in quasar/galaxy evolution schemes, and 3) study the effects of their powerful outflows on the ISM and star formation in the host galaxies. We will specifically search for extended molecular gas/dust emissions or extreme line kinematics indicative of blowouts, and estimate molecular gas/dust masses, the fractions of molecular gas participating in star formation, and star formation rates. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2019-04-11T17:27:07.000
596 2023.1.00154.S 0 Searching for volatile phosphorus at the epoch of planet formation The potential habitability of planets depends on the availability of the fundamental elements for bio-chemistry at their time of formation. Phosphorus is of particular interest as it is essential for the synthesis of DNA. To date, current detections of P-bearing volatiles toward forming stars are associated with shocks. This supports the understanding that the bulk of the elemental reservoir of P is locked up in refractory materials. But, with the detection of volatile P in comet 67P it is unclear if there is actually a significant volatile reservoir of P locked up in ices. The search for volatile phosphorus in planet-forming disks is an important step in understanding the delivery of this bio-essential element to planets. Therefore, we propose to observe the primary P-carriers PO and PN in the planet-forming disk Oph-IRS48. In this system, there is clear evidence for the sublimation of ices traced by complex organic molecules. If volatile P molecules are present in this disk, they should also be sublimated into the gas phase. Our proposed observations will be the first to fill a key gap between star-forming regions and comets. Intermediate-mass star formation ISM and star formation 3000-01-01T00:00:00.000
597 2018.1.01171.S 249 An ACA Survey of Dense Gas Across, the Nearest, Brightest Southern Galaxy Disks We propose to use the 7m+TP ACA to map high critical density 3mm lines (HCN, HCO+ and CS) across 11 nearby star-forming disk galaxies. We will measure the star formation rate per dense gas mass, the dense gas mass fraction, and how these quantities change as a function of environment within galaxies. Current measurements suggest both quantities vary, but galaxy-to-galaxy scatter and small number statistics limit our ability to understand these trends. Our targets overlap the PHANGS CO survey, which is characterizing the mean density, virial parameter, and Mach number of molecular clouds. This offers the unique opportunity to relate the dense gas mass fraction and star formation per unit dense gas mass to these molecular cloud properties, providing a strong test of theories in which the properties of molecular clouds set the amount and behavior of dense gas. Our proposed observations will double the current sample of galaxies with 3mm dense gas maps and triple the set where dense gas can be tied to molecular cloud properties. ALMA represents the only option to map these critical southern targets, and the ACA is ideal for this surface brightness-limited experiment. Starbursts, star formation, Spiral galaxies Active galaxies 2020-01-18T22:41:13.000
598 2012.1.00844.S 120 CO redshifts of SPT sources Recent ground and space-based multi wavelength (sub)millimeter surveys covering hundreds of square degrees have discovered a large number ofstrongly lensed, ultra-bright submm galaxies (SMGs). The largest of these, by nearly an order of magnitude at present, is the South Pole Telescope (SPT) survey, which covers 2500 square degrees. Its 1.4mm detection wavelength ensures a uniform source selection function across z=1-8. Both aspects make SPT the ideal survey to uncover substantial numbers of the elusive z>4 SMG population. We have been granted ALMA observing time in cycle 0 to perform unbiased redshift measurements in the 3mm band in 26 SPT source. This survey is a large success and yields 45 detected line features, 16 (>60%) redshifts at z>3 and two sources at z=5.7 which places them among the most distant SMGs known today. The resulting redshift distribution is almost flat between z=2.5-4.5, in contrast to experiments based on radio identified SMGs in the past with far reaching consequences for the obscured star formation rate density at high redshift. Here we ask to extend our extremely successful efforts to obtain molecular line based redshifts of the SPT sources. In this proposal we focus on a particularly deep part of the SPT-survey located at 23h LST from which we have selected a complete flux limited sample of 15 SMGs with S1.4mm>16mJy within a 15x15 deg^2 field (compared to S1.4mm>25mJy over 1300deg^2 in cycle 0). The broader range of lensed fluxes gives us the ability to investigate and correct for possible redshift biases in different regimes of lens magnification. Combined with the derived magnifications from our imaging project this sample will also help to construct intrinsic flux (and therefore luminosity) limited samples and will the statistics in our SMG redshift distribution to determine its shape in the critical redshift range z=2.5-4.5 more precisely. Sub-mm Galaxies (SMG) Galaxy evolution 2016-11-06T00:00:00.000
599 2022.1.00101.S 119 Heating and Cooling of the Interstellar Medium in Dusty Galaxies at Cosmic Noon The transformation of molecular gas into stars is a function of how gas heats and cools, the details of which can be measured by ALMA. To study how stars form at the peak epoch of star formation, we select a sample of 13 dusty, infrared (IR) luminous z~1-2 galaxies, the likes of which dominate the cosmic star-formation rate density at z~1-3, on the basis of bright Polycyclic Aromatic Hydrocarbon (PAH) emission detected in their Spitzer spectra which is essential for measuring the gas heating. In this survey, we will obtain [C II] and dust-continuum observations to measure their gas cooling, IR sizes and ISM properties. These observations will provide the first solid link between [C II] and PAH luminosities at z>0, increasing the sample of galaxies at cosmic noon with measured heating and cooling diagnostics by an order of magnitude, and provide a connection to the overall properties of dusty star-formation, answering the question: Are the high star-formation rates in z~2 dusty, star-forming galaxies powered by simply more gas, or are the ISM conditions different in ways that enable more efficient star formation? Starbursts, star formation Active galaxies 2023-12-28T17:18:28.000
600 2015.1.00502.S 6 Spatially resolving the circumstellar envelope of WISE J180956.27-330500.2, an object recently experienced an extreme mass ejection This proposal aims to resolve the circumstellar envelope of WISE J180956.27-330500.2, an object with an extremely optically thick circumstellar envelope using the long-baseline mode. Since its discovery in 2012 as an object showing significant change of the infrared fluxes in the last 20 years, we have carried out an intensive follow-up observation in various wavelengths to reveal its nature. Our ALMA Cycle 1 observation have detected CO(3-2) and SiO(8-7) lines on top of the relatively strong continuum. The expansion velocity of the molecules is 70 km/s. These observation data do not correspond to any kinds of known objects, and the nature of WISE J1810 has not been identified. To estimate the distance to the object and the luminosity of the object, we propose a high-spatial resolution observation of WISE J1810. The expected size of the object is 40-70 mas, and the ALMA's long-baseline observation shall resolve it. The observation will be carried out primarily in CO(2-1) line and continuum in Band 6. Asymptotic Giant Branch (AGB) stars Stars and stellar evolution 2017-01-29T13:42:28.000
601 2015.1.00752.S 5 ALMA Unveils the Hierarchical Formation of Massive Galaxies Our team has used ALMA continuum imaging from Cycle 0 and Cycle 2 to discover that wide-field Herschel and ASTE/AzTEC surveys can be used to uncover blends of multiple DSFGs with pairwise separations that are significantly smaller than what is found from ALMA follow-up of other single-dish surveys. Theoretical simulations have difficulty reproducing this population of multi-component and small-separation DSFGs, but they suggest that a portion of the population may be due to line-of-sight projection effects and are not physically related. We obtained CARMA and PdBI obsevations of CO(3-2) and CO(4-3) indicating this is not the case for one target, but a larger sample size is needed to push this test to the next level. We propose a redshift search for CO emission in 2 targets with four or more ALMA counterparts from our Cycle 0 program and CO imaging of 2 additional targets with 3 or more ALMA counterparts and a known redshift. The redshift search data are critically needed to test whether the ALMA counterparts are physically associated, and the CO kinematics are essential to inform theories of how stars form in these complex systems. Sub-mm Galaxies (SMG), Galaxy Clusters Galaxy evolution 2017-07-24T18:10:32.000
602 2016.1.01269.S 69 Stimulated AGN feedback in cluster cores ALMA has revealed that radio AGN drive massive molecular gas flows in galaxies, and has identified a population of slowly moving molecular clouds in massive galaxies that are difficult to understand. Observation indicates these clouds were lifted from the nucleus by rising X-ray bubbles, or the clouds formed in the bubbles' updrafts. We propose to test this model using ALMA CO(3-2) and CO(1-0) observations of two brightest cluster galaxies harbouring powerful radio AGN, molecular gas masses exceeding ten billion solar masses, and star formation rates of up to 140 solar masses per year. The results will yield new and significant developments in our understanding of radio-mode feedback, which is common to all elliptical galaxies and may drive their evolution. Outflows, jets, feedback, Galaxy groups and clusters Active galaxies 2018-06-09T05:08:18.000
603 2021.1.00327.S 60 The ultimate test of AGN feedback at cosmic noon: deep ALMA observations tracing molecular outflows and halo heating AGN feedback, in the form of massive outflows and halo heating, is regarded as the key phenomenon reponsible for quenching star formation in massive galaxies and resulting in the popultion of local passive, massive galaxies. Although AGN feedback has been investigated extensively in the local universe, the bulk of the quenching action is expected to happen at z~2. Only a few (often marginal) detections of AGN-driven molecular outflows have been obtained at high redshift, and only tentative detections of halo heating associated with AGN winds have been reported at high-z. We propose deep CO(3-2) and Band 3 continuum observations of a sample of AGN at z~2, representative of the dominant Black Hole accretion mode at this epoch, which have been already observed with ALMA and whose stacked spectrum shows indications of molecular outflows. The much deeper proposed observations will enable us to individually detect molecular outflows and also the SZ signal associated with putative halo heating generated by AGN winds. The results will enable us to directly test AGN feedback scenarios, and in particular the effectiveness of the ejective or delayed (halo heating/starvation) modes. Outflows, jets, feedback Active galaxies 2023-03-09T00:00:00.000
604 2015.1.00113.S 141 Arp 220 Nuclear Disks at 50 mas Resolution We propose ultra-high resolution (50uas, 20pc) imaging of Arp 220, the closest, brightest and best studied ultra-luminous IR galaxy (ULIRG). Our observations in the CO(1-0), (2-1) and (3-2), HCN(4-3), CS(7-6),(5-4) and (2-1) (all with their 13C isotopologues) and the dust continuum will resolve the gas structures and dynamics in the two (hypothesized) nuclear disks of this archetypical ULIRG. The observations will also place significant constraints on possible SMBHs. Indeed, our cycle 1 observations of Arp220 (Scoville et al. 2015), together with our extensive simulations, demonstrate that such extremely high fidelity observations are feasible, that will result in resolutions that exceed previous ULIRG observations by orders of magnitudes in beam area. Tracing a number of key diagnostic lines of the ISM will shed unprecedented insights in the inner workings of this prototypical ULIRG (gas densities, masses, outflows, gas dispersions), that hosts some of the most extreme star formation environments in the universe, both at low and high redshifts. Compact and extended configurations are requested to provide the required image fidelity at the superlative resolution of ALMA. Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Galaxy evolution 2018-07-17T19:55:40.000
605 2011.0.00039.S 0 The ALMA view of the cool dust in an extreme low-metallicity starburst v1.6 We propose Band 7, extended configuration, continuum observations of the most metal-poor starburst in the local universe, SBS 0335-052E. The starburst in SBS 0335-052E occurs in extreme conditions, dominated by Super Star Clusters (SSCs) which have formed in a relatively pristine interstellar medium (ISM) (12+logO/H=7.2). ALMA's superb sensitivity and spatial resolution can for the first time probe the cool dust in this tiny galaxy, and help understand how metal enrichment and dust production proceed in early stages of galaxy formation. Our analysis of the spectral energy distribution (SED) of this SBS 0335-052E suggests that the dust mass and dust-to-gas ratio (DGR) is highly uncertain; compared with the HI mass, the dust-to-gas ratios (DGRs) range from 3e-7 to 2e-5, much lower than predicted by a linear extrapolation of the DGR variation with metallicity. However, the SED fits are unconstrained, because there have been no detections of cool dust so far. We are likely missing a large fraction of dust mass traced by the cool dust which ALMA can now measure. SBS 0335-052 hosts six Super Star Clusters, spread over roughly 2.6 arcsec in diameter. Most of the star-formation activity occurs in the two brightest clusters, which host almost 10000 O stars in a compact region unresolved by the HST. With ALMA, we can assess the effects of feedback of the massive stars on the dust morphology and the clumping scale of the cool dust in an extreme unenriched ISM. Ultimately, our proposed observations can open a new window on the transition from metal-free star formation in the early universe to the chemically evolved massive galaxies typical of the current epoch. Starbursts, star formation, Dwarf/metal-poor galaxies Active galaxies 2013-10-25T08:44:50.000
606 2015.1.01384.S 22 Probing Subsurface Water Ice Reservoirs on Ceres Water is one of the most significant and abundant tracers to understanding the solar system, because of its direct connection to astrobiology and sensitivity to probing the physical and chemical state of planetary bodies. Ceres is a large reservoir of water in the inner solar system. The recent discovery of active water outgassing from Ceres, and the arrival of NASAs Dawn spacecraft at Ceres, raise the new urgency to determine the thermal environment and characterizing any subsurface water reservoirs on Ceres. We hereby propose observations of Ceres in October 2015 with the aim of constructing complete spatially resolved thermal maps of the object. These maps will allow us to constrain the subsurface temperatures down to the diurnal thermal depth of a few mm, identify the temperature environment that could possibly host stable underground water ice, and search for excessively high thermal inertia that could be a signature of subsurface water ice. This proposal is the start of a 5-year investigation funded by NASA to observe Ceres with ALMA in a full Ceres-year to constrain its subsurface temperature environment down to 0.5-1 m. Solar system - Planetary surfaces, Solar system - Asteroids Solar system 2017-01-08T18:29:16.000
607 2018.1.00627.S 35 Searching for hot molecular cores in the extreme outer Galaxy The recent discovery of a hot molecular core in a nearby low-metallicity galaxy, the Large Magellanic Cloud (LMC), suggests that the galactic metallicity has a significant effect on chemistry in warm and dense molecular gas associated with a protostar. While remarkable chemical differences are reported between the LMC and Galactic hot cores, it is still unclear if the observed chemical characteristics is essentially common in other low-metallicity environments or it is unique only in the LMC. Here we propose ALMA observations to search for hot cores in a star-forming region at the edge of our Galaxy. The proposed target, WB89-789, is an active star-forming region located at the extreme outer Galaxy (galactocentric distance ~20 kpc), where the metallicity is lower than the solar neighborhood by a factor of four. This low metallicity environment, which is common with the LMC, provide us with an ideal laboratory to test the universality of the low-metallicity molecular chemistry observed in the LMC. This proposal aims to elucidate a possible link between metallicity and hot core chemistry, particularly by focusing on properties of complex organic molecules and their parental species. Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds ISM and star formation 2020-08-14T08:16:22.000
608 2022.1.00007.S 0 Overture to the super maser flare in Orion KL 2024 A complete picture of Orion KL, the nearest high-mass star-forming region, is crucial in terms of understanding of high-mass star-formation. While it has been studied for a half century, there remains a number of unresolved properties. One of such outstanding characteristics is the super flare of the 22 GHz H2O maser, in which the flux density increases from kilo-Jy to Mega-Jy within a few years. Since the super maser flares were reported in 1985, 1998, and 2011, it would imply a 13-year period possibly caused by episodic dynamical processes. If it really has the periodicity, the next flare will start in 2024. Thus, we propose to start observations from the pre-flare phase in ALMA Cycle 9 to identify origins of the super maser flare. We will image the 183 GHz and 325 GHz H2O masers in Orion KL to compare positions and variabilities of that of the 22 GHz H2O masers. We will also explore a possible powering YSO of the super maser flare using continuum emission. The present study will contribute to understanding of broader context of high-mass star-formation such as time-variable activities of mass accretion and/or ejection, along with the pumping mechanisms in the maser flares. Outflows, jets and ionized winds, High-mass star formation ISM and star formation 3000-01-01T00:00:00.000
609 2017.1.00629.S 321 Constraining the cold accretion onto the most massive Black Holes The properties of the cold gas found in the cores of clusters of galaxies are relatively poorly constrained. Observations of the global emission from the ensemble of cold clouds traced by CO allow us to estimate the total mass and temperature of the gas. However, without information about the size and density of individual clouds, it is not possible to unambiguously determine its contribution to the baryon budget in the cluster core and how it fuels AGN activity. We propose to obtain CO(1-0) absorption observations toward the 23 brightest mm-continuum sources in cluster cores observable with ALMA to determine the properties of a statistically meaningful sample of these clouds. The results from these poor weather observations requested will form the basis of future observations to determine the chemistry and dynamics of these clouds. Outflows, jets, feedback, Galaxy groups and clusters Active galaxies 2019-09-14T16:20:00.000
610 2021.1.00854.S 112 Tracing planet-forming pebbles across the water snow line with the synergy of ALMA and JWST ALMA observations trace the pebble (mm/cm size grains) distributions in the outer parts (>10 au) of protoplanetary disks, but cannot directly inform on the pebble mass delivered into the rocky planet forming region at < 5 au, which has strong implications on the architecture and composition of forming (rocky) planets. Recent work proposed that chemical signatures revealed from mid-IR spectra could provide a synergic view of the evolution and drift of planet-feeding pebbles from the outer to the inner disk. With the launch of JWST, there is an urgent need to complete the upcoming JWST data with complementary ALMA data. We propose to observe 11 disks at 1.3mm with 0.05" resolution, which will complete a total sample of 60 disks that will be observed in multiple approved JWST/MIRI programs, but do not have high-resolution mm images yet. More importantly, our sample will double the number of mm-faint disks, which have bright water emission and are some of the best targets for inner disk chemistry studies. A joint analysis of high quality ALMA and JWST data will allow us to test if the inner disk water vapor is enriched by the inward drift of pebbles in a large and well-balanced sample. Disks around low-mass stars Disks and planet formation 2023-01-12T18:52:29.000
611 2012.1.00676.S 0 The black hole - galaxy mass relationship at redshift 6 We propose to make [CII] and rest-frame 160 micron continuum observations of a sample of z=6 quasars with observed black hole mass ~10^8 solar masses. The science goal is to measure the dynamical masses of the quasar host galaxies and determine the black hole to galaxy mass ratio at this epoch. Previous work at this redshift has been based on observations of SDSS quasars with black holes > 10^9 solar masses that are subject to a selection bias. Our aims are to measure the strength of the selection bias and hence the true relationship, which is a key constraint on theories of the early co-evolution of galaxies and their central supermassive black holes. The dust continuum luminosity measures the star formation rate to be compared with the black hole accretion rate. High-z Active Galactic Nuclei (AGN) Active galaxies 2015-03-04T12:39:44.000
612 2015.1.00804.S 75 The Galaxy Merger Process: Molecular Gas Properties at the Beginning and the End The galaxy merger process is still not well understood and more observational constraints are necessary to improve numerical simulations. We propose to observed two mergers (NGC 2623 and Arp 240) at opposite ends of the merger process in several 12CO and 13CO transitions. Combining the proposed observations with existing CO data, we will perform a radiative transfer analysis to constrain the physical conditions of the molecular gas at each merger stage. We will compare the physical conditions with other mergers at different stages to look for trends in the molecular gas properties, CO-to-H2 conversion factor and the [12CO]/[13CO] abundace ratio with merger stage. Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Active galaxies 2017-02-09T16:34:43.000
613 2023.1.01362.S 0 Pandora's ELPIS: The Emission-Line Protocluster Imaging Survey of the furthest overdensity beyond Pandora's Cluster How much of cosmic star formations is obscured by dust at the epoch of reionization (EoR)? Recently, ALMA has revealed the presence of dust out to z ~ 8, and the obscured star formation can be more prominent in a protocluster of galaxies. However, an unbiased search for dusty star-forming galaxies (DSFGs) at z ~ 8 remains a challenging task since virtually all studies that select z ~ 8 sources rely on the Lyman break technique, which biases against DSFGs, and no such overdensities have been identified so far. Here we propose the Emission-Line Protocluster Imaging Survey (ELPIS), a Band 6 [CII]+dust mapping of an 80"X40" area around the most distant known overdensity at z = 7.88 behind Pandora's Cluster, Abell 2744, which was recently confirmed by JWST. Strikingly, the number density of confirmed LBGs is 2-3 dex higher than in the general field, making this field an ideal place for a impartial search for DSFGs that have been overlooked. We will detect tens of DSFGs in addition to a fraction of known LBGs. This will present an order of magnitude increase in the number of known [CII] detections at z ~ 8, allowing us to address the obscured contribution to cosmic star formation. Galaxy Clusters Cosmology 2025-05-10T07:02:30.000
614 2022.1.01604.S 0 A new, fast, ultradeep constraint on the ISM content of the first generations of massive quiescent galaxies. The question of whether quenching requires complete gas depletion does not have a clear answer yet. The literature offers contrasting results, whose intepretation requires large statistical samples that are not yet available. We propose to take advantage of a new, compelling method to measure the total gas fraction of high-z quiescent galaxies by using the brightest molecular gas mass tracer, i.e. the [CII] 158 microns fine-structure emission line. This line has long been overlooked since it is predominantly used for star-forming galaxies. However, it becomes particularly useful for quiescent galaxies at high-z since these are often selected to have suppressed sSFRs - but not absent - with respect to main sequence galaxies. By exploting ALMA bands 8-9-10 we will observe gas fractions down to 1% (without strictly requiring strong lensing) in 8 spectroscopically confirmed, well-studied, massive quiescent galaxies at 1.22.9. Galaxy structure & evolution Galaxy evolution 2024-09-22T13:43:42.000
615 2023.1.00601.S 0 Probing molecular gas in the radiogalaxy Coma A, a unique local case of jet triggered star formation We propose to obtain CO(1-0) observations of the nearby radio galaxy Coma A (z=0.085). The VLT/MUSE data revealed a spectacular nebula of ionized gas enshrouding the radio source and the presence of young stars located as far as 50 kpc from the nucleus. The shocks induced by the expansion of the radio lobes are causing the collapse of cold gas clouds, triggering star formation (SF). With the proposed ALMA observations we will explore the distribution of the molecular gas, the reservoir of material needed for star forming regions, and study its kinematics. This will enable us to probe the effects of the active nucleus on the surrounding medium to understand whether the radio source, that is currently forming stars, will cause the sterilization and quenching of future SF in the host. Coma A is a unique source in the local Universe and it represents a perfect laboratory to study jet-triggered SF, a process that has been fundamental for the evolution of galaxies in earlier epochs. The proposed observations represent an exceptional opportunity to study in detail the physical interaction between the active nucleus and its surroundings and to explore the effects of positive feedback. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 3000-01-01T00:00:00.000
616 2017.1.01401.S 13 Unvealing the true nature of the subluminous young stellar object Par-Lup3-4 Par-Lup3-4, located close to the brown dwarf limit is an underluminous object for its spectral type which is also accreting. We propose Band 7 observations of CO(3-2) and continuum of Par-Lup3-4 to study the morphology and the physical parameters of the dust and gas disk surrounding the object. These observations will also allow us to confirm the low velocity molecular outflow that was detected recently in previous ALMA band 6 observations. Using the continuum emission from the dust we will measure the spectral index between 1.3 mm (using previous ALMA b6 observations) and 870 microns to probe possible evidence or grain growth inside the disk. Another important goal is to study the kinematics of the disk and estimate the dynamical mass of ParLup3-4, which will reveal the true nature of this object in the limit of the substellar regime. This proposal requesting only 2.17 h time, will provide unique information on the origin of low mass stars close to the brown dwarf boundary. Low-mass star formation ISM and star formation 2019-04-12T08:37:04.000
617 2019.1.00473.S 6 Ionized Gas, Radiation Field, Masses, and Dust Temperature in Forming Massive Clusters in the NGC253 Starburst Our ALMA observations in B7 at 0.1" resolution identified massive super star clusters (SSCs) in the process of formation in the core of the NGC253 starburst (Leroy et al. 2018). Follow up at 0.03" measured sizes and uncovered outflows from these SSCs (Levy et al., in prep.). The characterization of these clusters is needed to understand the high-efficiency "starburst mode" of star formation, the life cycle of massive clusters, and the effects of massive-star feedback on star forming clouds. This proposal aims to: 1) directly measure the ionizing photon flux and synchrotron emission in these objects, which impact the stellar masses and ages of the clusters, 2) constrain the dust optical depth and dramatically improve estimates for the temperature and gas mass of these sources, and 3) measure the sizes of the HII regions associated with these SSCs and to search for ionized gas outflows. Our observations also yield a direct constraint on the hardness of the ionizing radiation field and on the high mass end of the stellar IMF in these SSCs. These data are key to build a picture of the dominant star formation mechanism in starbursting systems at low and high redshift. Starbursts, star formation Active galaxies 2022-10-19T22:26:01.000
618 2018.1.01305.S 33 Resolving stellar IMF and evolution modes in dusty starbursts at high redshift We request ALMA observing time in order to built on our success of using it as a powerful new probe of the stellar Initial Mass Function (IMF) in dusty starburst galaxies (Zhang et al. 2018, Nature). Isotopes of CNO elements are solely produced by stellar nucleosynthesis, and ejected into interstellar medium (ISM) imprinted with IMF. Accomplished with galactic chemical evolution modelling, which is well-benchmarked against rich data in the Milky Way, the 13CO/C18O line ratio has been demonstrated as a powerful tool for probing stellar IMF in galaxies across cosmic time. This opens up a unique new window of exploring fundamental issues of galaxy evolution in the Early Universe, exploiting recent advances in stellar physics. We propose to perform deep observations of 13CO and C18O lines in two strongly lensed starbursts, with mid-resolution, to a) resolve spatial variations of the IMF within them, b) compare IMF and SFR surface density in extreme conditions on kpc scales, and c) connect the resolved IMF distribution with those found in local early-type galaxies, by tracing the evolution of both stars and ISM across cosmic time. Sub-mm Galaxies (SMG), Galaxy structure & evolution Galaxy evolution 2019-11-28T14:35:47.000
619 2021.1.00162.S 5 Constraining the Jupiter Equatorial Oscillation from ALMA direct wind measurements An equatorial quasi-periodic oscillation in temperature and wind direction was discovered in the 1950s in Earth's stratosphere. Comparable equatorial stratospheric oscillations exist in Jupiter and Saturn. Our project aims at better understanding the processes that cause and maintain the Jupiter Equatorial Oscillation (JEO), which occurs between 1 and 30 mbar. We propose to map the winds around Jupiter's equator at two different stratospheric levels. We will observe at 1 mbar, using HCN(4-3), and 5 mbar, using CO(3-2). These two levels in the stratosphere are, respectively, the levels where the JEO is generated and a level where the JEO winds can reach ~200 m/s. We also propose to produce two wind maps separated by 6 months (March and September 2022) to investigate how the vertical structure of the JEO zonal winds evolves at different phases of the oscillation. Solar system - Comets Solar system 2024-01-03T18:06:24.000
620 2021.1.01305.S 10 Molecular outflows in the epoch of reionization: OH observations of a quasar at z=6.04 Molecular outflows are important in galaxy evolution owing to their role in regulating star formation and enriching the circumgalactic medium with metal-rich gas and dust. Although molecular outflows have been discovered in many active galactic nuclei and starbursts, evidence in quasars in the Epoch of Reionization (EoR; 6<~z<~20) is scarce. How prominent was feedback in dusty quasars during this epoch? To search for molecular outflows, we propose sensitive OH 119 um observations toward J2054-0005, a quasar at redshift z=6.04. Recently, OH absorption has proved to be a robust tracer of molecular outflows up to z~5, but detections in EoR quasars are notably lacking. Our target exhibits a bright compact continuum source and a prodigious star formation rate of ~1900 Msun/year, making it an ideal object to expect quasar feedback and demonstrate the potential of the OH 119 um line in tracing molecular outflows at z>6. We will estimate the outflow properties, such as kinetic energy and mass outflow rate. The results are expected to provide valuable information for galaxy evolution models. High-z Active Galactic Nuclei (AGN) Active galaxies 2023-08-31T05:05:13.000
621 2019.2.00218.S 126 ACA Linescan of 2 z>5 SMGs in the CDF-S We propose ALMA linescans for a complete sample of 58 S(850um)> 1.7 mJy SMGs from an extremely deep SCUBA-2 CDF-S map, all with accurate positions/fluxes from prior band 7 ALMA imaging. We aim to detect 2+ bright CO transitions in the majority of SMGs, establishing firm redshifts (unlocking great potential for individual and stacked spectral constraints from radio to X-ray), robust molecular gas (mass, excitation curves, kinematics, t_depl) and dust properties (mass, temperature) estimates. These precise physical constraints, which are unattainable by UV/opt/NIR methods, will advance our understanding of star formation in this critical flux regime, which accounts for ~30% of the 850um background. The samples completeness and the unsurpassed ancillary data in the central part of the CDF-S (deepest Chandra, Herschel, HST NIR/optical, etc.) make it a unique dataset for understanding the SMGs. Starburst galaxies, Sub-mm Galaxies (SMG) Active galaxies 2022-12-16T23:57:22.000
622 2018.1.01034.T 66 Constraining Jet Formation and Evolution with X-ray Binaries Relativistic jets launched by accreting black holes can affect star formation, galaxy evolution and even the distribution of matter in the universe. Therefore, it is essential that we understand the process of accretion and the physics of these accretion-fed outflows. Black hole X-ray binaries (BHXBs) provide ideal laboratories for probing jet phenomena due to their rapid (day-week) evolution timescales. In particular, broad-band spectral measurements of jet emission in BHXBs during bright outburst periods allow us to constrain the physical conditions in the jet, which can then be coupled to the properties of the accretion flow, probing the mechanisms that govern how jets are launched and quenched. The mm/sub-mm regime bridges a crucial gap between radio and IR frequencies, as data in this regime are essential when performing detailed spectral modelling. We propose targeting the next outbursting BHXB with ALMA ToO observations, to accurately measure the evolving mm/sub-mm flux. Coupled with our exceptional multi-wavelength coverage, we will constrain the dynamic broad-band spectral energy distribution in BHXBs with unparalleled accuracy. Black holes, Transients Stars and stellar evolution 2020-08-29T16:55:18.000
623 2017.1.00373.S 119 Molecular gas and dust in the reionization epoch: massive vigorously star forming galaxies at z~7 Using state of the art FIR/mm photometry in the COSMOS field, we have discovered and solidly detected four FIR/mm luminous galaxies that could be the most distant ever known, with photometric redshift z~7 and possibly higher. Their FIR/mm colors are even redder than the most distant known FIR/mm galaxy HFLS-3 at z=6.337, while their large stellar mass and dust reservoirs make the redshift confirmation the most important step to proceed. We propose to use ALMA to confirm their very high redshifts via detection of multiple CO (and other weaker) transitions in Band 3 and with final confirmation via [CII] in Band 6. This project will be strongly constraining the earliest epochs of massive galaxy formation in the young Universe, unveiling the existence of vigorous star forming events that were building the first generation of ultra-massive galaxies, progenitors of local giant ellipticals. Sub-mm Galaxies (SMG) Galaxy evolution 2019-01-30T22:39:06.000
624 2013.1.00151.S 86 The gas content and gas depletion time of massive, normal star forming galaxies beyond z=3 We request rest-frame ~250um continuum observations of a complete sample of 86 massive (log(M_stellar/M_sun) > 10.5) normal star-forming, i.e. main sequence, galaxies at high redshift in an epoch of increasing SFR density (z~3-4) identified in the 2 sq.deg COSMOS field. Using our new, empirically calibrated correlation between mono-chromatic sub-mm luminosity and total gas content we will measure the cool gas mass in these systems. Combined with estimations of their star formation rates from the IR spectral energy distribution (and incoming high-sensitivity Jansky VLA radio continuum imaging), the gas depletion time, or its inverse - the star formation efficiency, of each galaxy will be derived. The proposed observations will provide the first solid measurement of the mean depletion time for normal star-forming galaxies beyond the peak of star formation activity (at z~2-3). A reduced depletion time (relative to local star-forming galaxies) has been inferred for z~1-2.5 samples, but conflicting results based on small (< 5) samples exist beyond these redshifts. These proposed observations are vital in providing the necessary constraints for current galaxy evolution models. Lyman Break Galaxies (LBG), Galaxy structure & evolution Galaxy evolution 2016-03-10T14:05:13.000
625 2018.1.01113.S 43 The Nature of the Central Disk in V Hya: A Carbon Star Ejecting High-Velocity Bullets The carbon star V Hya is experiencing heavy mass loss as it undergoes the transition from an AGB star to a bipolar planetary nebula (PN), and is possibly the earliest object known in this brief phase, which is so short that few nearby stars are likely to be caught in the act. Our STIS/HST data show a 25-yr history of high-velocity (>200 km/s) bullet-like ejections from the star. SMA CO observations with ~3.5" resolution also reveal an extended high-velocity, collimated outflow (aligned E-W) and a N-S elongated dense waist (size 8" in CO 3-2) on ~100-250 yr timescales. Our coronagraphic polarimetric imaging at 1 micron shows an inclined disk of size 0.6" (or 240 AU) at the center of the waist. We propose to observe the CO J=3-2, 2-1 lines and 0.87-1.3 mm dust continuum in V Hya at ~0.1" resolution to (a) determine whether this disk is rotating or expanding, and to constrain its mass, (b) study CO bullets close to the central source. These observations offer us an unprecedented opportunity to test binary interaction models for making the jet engines that launch the jet-like outflows that produce bipolar PNe outflows, and the disks that are the launch-sites of these outflows. Asymptotic Giant Branch (AGB) stars Stars and stellar evolution 2020-07-24T01:00:01.000
626 2022.1.01603.S 20 ALMA Cycle9: Chemical differentiation between starless twin substructures The self-gravitating substructures in the starless cores are expected to form multiple stellar systems. However, such substructures at starless phase is rarely seen. We propose to observe G205.46-14.56M3, a starless core habors two substructures with a separation of 1200au, consistent with the turbulence-dominated core fragmentation scenario. As N2D+ is depleted, we propose to use H2D+ and D2H+ to trace the central dense region. It has been shown that the ortho-H2D+/para-D2H+ ratio is a reliable collapsing timescale indicator (Bovino et al. 2021). Therefore, we propose to observe ortho-H2D+ and para-D2H+ towards two substructures to derive their physical properties. The ratio will give us the ages of the two substructures of G205.46-14.56M3. By comparing the ages with the free-fall time, we test if they follow the rapid collapse as predicted by the turbulent-fragmentation theory. Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry ISM and star formation 3000-01-01T00:00:00.000
627 2019.1.00582.S 6 WISDOM: NGC0383: The Most Accurate Extragalactic Supermassive Black Hole Mass Ever Measured We propose to make the most accurate supermassive black hole (SMBH) mass measurement ever beyond our own Milky Way in the radio galaxy NGC0383 (radio source 3C31), also reaching closer to the SMBH than any other measurement (except again the Milky Way and the recent EHT measurement of the M87 SMBH). With 0.024" resolution, we can resolve the molecular gas accretion disc down to 25,000 Schwarzschild radii, a factor of 2 closer to the BH than the best existing megamaser measurement. In addition to the extremely precise SMBH mass measurement, we will probe with unprecedented detail the region of NGC0383 within the SMBH sphere of influence, all of which is within the Bondi radius. We will search for signatures of warps and/or non-circular motions that may be funnelling gas towards the SMBH, shedding light on the feeding of such radio-loud/jetted systems, and we will attempt to constrain accretion disc models and their connection to the larger scale disks/fuel reservoirs, also probed here. Early-type galaxies, Galactic centres/nuclei Galaxy evolution 2022-10-29T18:53:45.000
628 2021.2.00180.S 183 Resolving systematics in the Planck sub-millimetre spectra of radio-loud AGNs We have found the possible dust contamination as denoted by the sub-millimetre excess in the radio spectra of bright AGNs observed during the Planck campaign. The origin of the dust in most cases seem to be intrinsic as they are unaffected by the Galactic dust. A majority of sources in the sample showing this trait are blazars, which as per the definition are old ellipticals with no significant traces of dust. The SEDs of these sources seem to be unlike the starburst galaxies that are known to have higher gas/dust temperatures. We propose continuum observations of the dust emission in 16 AGNs. Our goal is to characterise the nature and origin of the sub-mm flux in terms of the particle acceleration in addition to the dust in these objects and re-visit the evolutionary stage of AGNs in elliptical galaxies. Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2023-06-07T09:31:22.000
629 2015.1.01096.S 52 ISM and Kinematics of a Luminous UV-Selected Galaxy in the EOR Recent ALMA observations have successfully pushed the detections of [CII] from normal star-forming galaxies to z ~ 5-6. Here we propose to further push this into the epoch of reionization (EOR). We will conduct sensitive Band-6 observations to detect the [CII] and far-IR continuum from a carefully chosen z ~ 7 Lyman-break galaxy in the HUDF. The galaxy is unanimously agreed by many groups to be at z ~ 7. It is among the brightest z ~ 7 galaxies and has a star formation rate of up to 110 Msun/yr. It is thus the best candidate to host strong [CII] emission. Its morphology shows hint of galactic interaction. Our observing strategy does not only provide the sensitivity to detect the [CII] line, but also the frequency coverage to encompass any potential redshift uncertainties and velocity offsets between its Ly-alpha and [CII] lines. Our ALMA observations will pin down its redshift and reveal the potentially very interesting kinematics. The [CII] and far-IR continuum results will allow us to test the dust properties, obscured star formation, and the nature of UV extinction in this galaxy. These will lead to a better understanding of the sources of the ionizing photons in the EOR. Lyman Break Galaxies (LBG) Galaxy evolution 2017-07-28T01:16:28.000
630 2015.1.00263.S 3 Multi-phase outflows in ULIRGs: Mapping the massive cold component Using H2 2.12micron integral-field spectroscopy (IFS), we have recently characterized the hot molecular component of massive outflows in local IR bright starbursts. In particular, high velocity (~1000 km/s, FWZI) hot molecular outflows extended over 2-3 kpc regions have been identified in three low-z ultra-luminous infrared galaxies (ULIRGs). Based on our previous works (Emonts+14, García-Burillo+15), we predict total cold molecular outflowing masses of ~10^8 Msun and outflow rates of 15-200 Msun/yr. Here we propose to obtain deep 0.35" CO(2-1) images of these three ULIRGs to: (i) map the massive cold molecular phase of the outflows; (ii) establish the mass loading and momentum boost factors; (iii) and, for the first time, determine the multi-phase (cold/hot molecular and ionized) sub-kpc structure of the outflows in the most extreme local star-forming galaxies. Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) Active galaxies 2017-10-22T02:28:25.000
631 2022.1.01220.S 9 Star Formation Under the Cosmic Microscope with JWST + ALMA The James Webb Space Telescope (JWST), through the Directors Discretionary Early Release Science (ERS) Program, is going to spend 55 hours observing four gravitationally lensed starforming galaxies to spatially resolve the stellar components and the star formation in galaxies across the peak of cosmic star formation (1.3 Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) Galaxy evolution 3000-01-01T00:00:00.000
632 2018.1.00973.S 16 Probing the effects of a tidal encounter on the sub-structure of a protoplanetary disk RW Aur is a T Tauri star that has very recently undergone a tidal encounter with star B, which is also hosting circumstellar material. This object provides the unique opportunity to explore the impact of a star-disk fly-by in perturbing and disrupting part of the protoplanetary disk orbiting a new born star. Whereas this event is extremely rare in low mass star forming regions, it is expected to occur more frequently in dense and massive young associations, which are however too far for disks to be explored at high spatial resolution. How these impulsive events affect the angular momentum evolution of disks, the accretion rate onto the star and ultimately the planet formation potential of protoplanetary disks is still an open question. In this context, the spectacular RW Aurigae system offers the opportunity of a rare insight into this question. With this proposal we aim to probe the effects of the tidal encounter onto the circumprimary and circumsecondary disks, retrace past orbital interactions, and identify possible outflows triggered by the encounter. Disks around low-mass stars Disks and planet formation 2020-01-10T10:17:50.000
633 2016.1.01290.V 0 Pinpointing the Highly Magnetized Twin-Jet Base Near a Supermassive Black Hole We propose to observe the innermost region of the nearby galaxy NGC 1052 with the EHT and ALMA37 at Band 6 to probe the origin of the twin jet and potentially the acretion disk region. The source is located a distance of 19 Mpc, similar to M87. In contrast with the one-sided jet of M87, NGC1052 shows a twin jet with both the jet and counterjet bases being visible and unaffected by differential Doppler boosting. Using VLBI at 3mm wavelengths, we have recently shown that the twin jets are detectable and extend from a bright and compact central feature. This marks the location of the black hole where we estimate magnetic fields between 360 G and 70000 G to reside. VLBI with EHT+ALMA at Band 6 will provide unprecedented angular resolution and sensitivity that are vital to directly investigate the region where both jets intitially form in greater detail than any previous observation. The morphology, close proximity and strong radio emission makes NGC1052 a prime target to examine the formation of a jet powered by a supermassive black hole at scales of several hundreds of gravitational radii without Doppler boosting complications. Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2018-10-20T14:57:17.000
634 2012.1.00323.S 0 The nature of the ISM in galaxies during the star-formation activity peak of the Universe v2 The nature of the ISM in typical star-forming (SF) galaxies during the peak in SF activity of the Universe (z = 1-2) is still an open question. It is unclear what the characteristic ISM properties of typical SF galaxies is at z∼1. We propose to observe CO and C lines to determine the dominant physical properties (density, temperature, local radiation field, carbon abundance) of the star-forming ISM in three star-forming galaxies at z ∼ 1.2. The proposed targets are typical examples of the galaxies that are responsible for the bulk of SF during the SF peak of the Universe. These observations can reveal if the physical state of the ISM in such galaxies is similar to local counterparts – a scaled up version of typical nearby galaxies – or significantly different. These observations are the first such attempt towards a detailed understanding of the nature of the ISM in typical star-forming galaxies during the z =1-2 SF peak. Galaxy structure & evolution Galaxy evolution 2015-04-16T14:56:06.000
635 2016.1.00928.S 192 Early Stages of Dense Core Evolution With this ACA standalone proposal, we intend to survey dense cores aiming at investigating the evolution of density profiles at the early collapsing phases. Evolution of low-mass pre-stellar cores is characterized by the radial density profile. Our ALMA observations toward MC27, which is at very early stage of the low-mass multiple star formation in Taurus, shows density enhancement even at the very center while most of the other pre-stellar cores have a flat inner density profile at r < 1000 AU. We investigated the dust column density profile observed by large aperture single dish telescopes toward dense cores at d~150pc, and selected 16 targets as candidates for evolved starless cores that are very close to protostar forming phase. The ACA can look into the central part of each core down to ~5" (~ 750 AU) where the density exceeds 10^6 cm^-3, which is the characteristic density of the threshold for the dynamical collapse. The outcome of this survey will tell us the initial conditions of dense cores evolving toward star formation under the dynamical collapsing phase. Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) ISM and star formation 2019-11-11T00:00:00.000
636 2017.1.01674.S 22 The resolved view to the molecular gas content in normal disks galaxies at z = 1.46 Sensitive measurements of CO(2--1) emission line of high-z galaxies at ~kpc-scale is possible with ALMA. We propose to complement our recently obtained SINFONI AO-assisted observations of Halpha emission line of star-forming galaxies at z = 1.46 (SHiZELS survey) with a CO line emission map at matched resolution. We already have CO unresolved data for two targets within the SHiZELS survey. This data will guarantee the "success" of our proposed observations in order to put SHiZELS-8 and COS-30 in the global context of galaxy evolution through a resolved and unique view to the efficiency of star formation (SFR/M_H2) and its relationship to the star formation activity, gas dynamics of the galaxy and the clumpiness properties measured from Halpha emission line and its progenitors seen in CO emission line. By comparing the molecular masses for those systems with its dynamical masses inferred from dynamical models we will be able to give upper limits to the CO-to-H2 conversion value on 'typical' star-forming galaxies at high-z. These observations are indended to be part of my PhD thesis, a project which exploits IFU-AO data to understand the origin of clumpy-disk galaxies at high-z. Galaxy structure & evolution Galaxy evolution 2018-12-11T21:41:33.000
637 2013.1.01052.S 5 Tracing the Star Formation at z=6.11 with [OIII] The cosmic star formation near and beyond z~6 was actively taking shape and evolving through the assembly of normal galaxies eventually to merge into the larger more luminous systems. Probing the ISM in some of the earliest star-forming galaxies is ALMA's flagship. We propose to use ALMA to probe a z=6.11 galaxy of low mass and low metallicity using the 88 micron [OIII] which is the most luminous of the FIR fine structure lines in low-metallicity galaxies. The 88 micron [OIII] line follows tightly the star formation rate and has recently been calibrated as a star formation rate tracer in low-metallicity galaxies. Together these properties highlight the [OIII] line as the best probe of the high-z, low metallicity Universe. Additionally, we propose to observe the 158 micron[CII] line to benchmark the use of the [OIII]/[CII] ratio as an important probe of the structure of the ISM in high-z galaxies and to place constraints on the structure in terms of neutral phodissociation/molecular gas and ionized low density gas. Lyman Alpha Emitters/Blobs (LAE/LAB), Starburst galaxies Galaxy evolution 2015-07-03T00:00:00.000
638 2015.1.01247.S 36 Molecular Gas in Dusty Quasars: Fuelling the Formation of Massive Galaxies at z~2.5 We propose to detect 12CO(3-2) in 4 dust-obscured (Av~2.5), high luminosity (Lbol~1e14 L0), high star formation rate (SFR > 500 M0/yr) quasars at z~2.5 that are caught in a transformative, radiative-feedback dominated phase as they are transitioning from massive starburst galaxies to unobscured quasars. These dust obscured quasars are the highest luminosity quasars currently known at the main epoch of galaxy and supermassive black hole assembly. The proposed CO detection experiment will lead to a five-fold increase in the number of z~2-3 intrinsically luminous, ALMA-accessible quasars where molecular gas has been detected, thus paving the way for future high-resolution observations to look for signatures of AGN triggering and feedback in these systems. Previous searches for molecular gas in high redshift quasars have tended to focus on gravitationally lensed, intrinsically lower luminosity systems or quasars at redshifts above 4. Studying the molecular gas in our high luminosity, highly star-forming quasar hosts will therefore enable new insights into the interplay between star formation and black hole accretion at an epoch when both quantities were at their peak. Starburst galaxies, High-z Active Galactic Nuclei (AGN) Active galaxies 2017-03-08T13:50:51.000
639 2017.1.01311.S 18 Remote Detection of Organics in Enceladus' Plume Enceladus, one of Saturn's major moons, is the source of a spectacular water plume originating from a global sub-surface ocean. This plume provides a unique opportunity to trace the composition of an underground water reservoir in the outer Solar System remotely. Excitingly, Cassini has measured high abundances of small organic molecules such as HCN and H2CO in the plume, suggestive of a rich underwater organic chemistry. Identification of salts and molecular H2 in the plume has drawn comparisons to the hydrothermal vent environments in Earth's oceans. More detailed and confident characterization of the plume will be difficult, however, as the Cassini mission is ending and no additional flybys will be conducted. Additionally, there is a persistent worry that some of the organics Cassini is `measuring' may be residual from Titan flybys. We therefore propose to use ALMA to obtain an independent data set securing the existence of the most detectable plume organic, HCN. In addition to providing unambiguous evidence of organics in Enceladus' plume, detection of HCN will establish ALMA as a powerful instrument for remote monitoring of the plume composition and its temporal evolution. Solar system - Planetary atmospheres Solar system 2021-01-08T19:13:37.000
640 2013.1.01358.S 9 Galaxies in (and behind) two massive high-redshift clusters We propose continuum, CO(4-3), and [CI] observations of 70 galaxies in the two highest redshift members of a mass-selected Sunyaev-Zel'dovich effect cluster sample. By observing the merging z=0.87 cluster ACT-CL J0102-4915 "El Gordo" and the more regular z=1.06 cluster ACT-CL J0546-5345, we will be able to study how total gas content (for which dust mass is a proxy) and molecular gas content vary with galaxy property, environmental density, and dynamical state in the most massive clusters to be assembled at early times. In addition (particularly for "El Gordo," recently the subject of exquisite strong and weak lensing models), we will be able to characterize the properties of "ordinary" dusty background galaxies that have been gravitationally lensed by the clusters. Sub-mm Galaxies (SMG), Galaxy Clusters Galaxy evolution 2016-05-07T14:45:45.000
641 2015.1.00960.S 126 SiO megamasers in AGN accretion disks We propose to search for 86 GHz SiO megamasers in 12 galaxies known to have 22 GHz H2O megamaser emission, arising from gas in the circumnuclear accretion disk around the central supermassive black hole. We are motivated in part by the recent detection of SiO as a megamaser in the circumnuclear disk of NGC 1068 (Wang et al. 2014), which is known to host a strong 22 GHz water megamaser. If we detect a disk-like profile in SiO emission, we can use the known (from 22 GHz observations) dynamics to associate the SiO masers with specific regions of the circumnuclear disk. Furthermore, a detection of SiO megamasers in a disk system would provide a fantastic target for current millimeter-wave VLBI facilities, opening up opportunities to map the innermost regions (<~0.1 pc) of the circumnuclear disk. Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei Active galaxies 2017-12-17T05:57:49.000
642 2023.1.00868.S 0 A search for cold, carbon-rich accretion streams in a massive halo at z=2.9 Cold accretion of gas from the cosmic web sustains star formation and supermassive black hole activity across cosmic time. Theory predicts the gas is funneled into the core of massive halos through narrow and cold streams, but direct observational evidence of them is scarce. In this proposal, we search for extended cold gas via the [CI](1-0) tracer in the environment of RO-1001, a massive protocluster of galaxies at z=2.9. Previous spatially and spectrally resolved observations of the diffuse Lyman Alpha (Lya) emission associated with this protocluster showed tantalizing hints of inflowing motion along three narrow filaments that connect at the center of the system. Encouraged by the recent detection of molecular [CI]-emitting streams in a similar Lya nebula, we expect to find the truly cold counterpart of the Lya filaments, finally witnessing the fuel of star formation being served into a growing halo. Lyman Alpha Emitters/Blobs (LAE/LAB), Galaxy structure & evolution Galaxy evolution 2025-01-05T16:00:10.000
643 2022.1.00160.S 10 Resolved CI study of different star forming environment CI has been favored as an alternative molecular gas tracer due to its simple 3-level fine structure lines. A tight linear relation has been found between global CI and CO 1-0 luminosity, suggesting CI works well as a global gas tracer. However, only a handful of studies have focused on CI variations within galaxies. A recent study of the LIRG IRAS F18293-3413 shows a superlinear relation between CI and CO 1-0 luminosity at 300 pc scale, which can be due to various enviromental factors. To further study this relation, we propose to observe CI 2-1 along with Band 10 continuum at ~200 pc scale for two nearby galaxies (NGC 3267, NGC 660) and a LIRG (NGC 5104), which already have archival CI 1-0 observations. We also propose for complementary CO 1-0 observations for the galaxies that do not have suitable archival CO data. From these observations, we will fully constrain the gas properties and split out the influence of different enviromental factors onthe CI-CO correlation. Galaxy chemistry, Giant Molecular Clouds (GMC) properties Galaxy evolution 2024-01-10T20:03:14.000
644 2021.1.00782.S 10 A deep kinematical study of the young planetary system PDS 70 Although several thousand exoplanets have been detected, many questions regarding their formation process are still open, largely hampered by the lack of observational constraints. PDS 70, with two planets directly imaged within a protoplanetary disk, is the so far only planetary system which has been directly caught during its formation. This system is thus a unique laboratory where the kinematical imprints of directly detected forming planets on their host protoplanetary disk can be observationally probed. With this proposal we aim to study the PDS 70 disk at the 13CO line in Band 7, in order to trace the kinematic disk structure deeper in the disk than ever before. While corresponding long-baseline observations targeting the 13CO isotopologue are already available in the archive, we ask for a completion of these data with short baseline observations, in order to recover the full emission of the disk. The analysis of these data will provide the first multi-line kinematic view of a directly detected protoplanetary system at formation. Exo-planets Disks and planet formation 2024-03-12T00:00:00.000
645 2017.1.00358.S 90 CO spectral imaging the hosts of the most extremely-luminous AGNs. A new class of extremely luminous active galaxies, `HotDOGs', were found by mid-IR selection from the WISE all-sky survey. HotDOGs are a population of powerful AGNs with characteristic hot far-IR SEDs, and luminosities reaching over 10^14 Lsun. They have well-defined redshifts, luminosities & SEDs, and are as numerous as comparably-luminous optical QSOs. HotDOGs' luminosity is dominated by very-obscured AGN, unlike either low-z ULIRGs or high-z submm-selected dust-enshrouded galaxies (SMGs/DSFGs). HotDOGs likely offer key tests of feedback/accretion. We propose sensitive Band-3 spectroscopy of the ISM in a complete sample of 10 HotDOGs/host galaxies, to reveal the size, morphology and dynamics of the molecular gas; and thus give the abundance of fuel for their AGNs, and the strength of their outflows. HotDOGs are the MOST extreme galaxies, forming their blackholes and undergoing feedback at the greatest rates: our spectral probe of their brightest CO lines will reveal the processing and consumption of gas in these dramatically luminous galaxies at an epoch when galaxy formation was at its most intense, and perhaps show how this remarkable phase is initiated and terminated. Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) Active galaxies 2019-01-06T15:56:26.000
646 2018.1.01003.S 70 The Role of Magnetic Fields within Dense Molecular Filaments in Vela C Recent large scale maps of magnetic fields in molecular clouds show that many (perhaps most?) are consistent with having a dynamically important magnetic field. How then do dense structures such as filaments and cores manage to form from a globally magnetized cloud? In this proposal we aim to determine how the gas density distribution is affected by magnetic fields within dense filaments in the young, nearby GMC Vela C (d~700pc). Our ALMA Band 6 observations of the two densest filaments in Vela C will be compared with BLAST maps of large and intermediate scale cloud magnetic fields and 19 arcsec resolution APEX polarimetry maps. Our goal is to 1) determine whether the observed orientation of the magnetic field perpendicular to the dense filaments holds on sub-filament scales, and 2) determine both the filament fragmentation on small scales and also whether these filaments are currently forming protoclusters. We also target lines of several intermediate and high density tracing molecules that, where detected, can be used to determine whether gas is being accreted on to the filaments primarily parallel to the magnetic field (as predicted for a cloud with strong magnetic fields). High-mass star formation, Intermediate-mass star formation ISM and star formation 2021-01-10T16:40:02.000
647 2019.1.01303.S 15 How to Feed a Torus: Resolving the center of Circinus AGN tori are fundamentally important components in models of active black holes, however their typical sizes, geometry, and structure are poorly constrained. We propose to conduct 0.02" to 0.2" (0.4-4 pc) Band 3 and Band 7 observations of the central 300 pc of Circinus to make the highest-ever resolution study of an AGN torus and probe its connection to the surrounding gas. These observations will resolve the compact torus and the distribution of surrounding gas on scales from 0.4-300 pc and constrain the kinematics of the gas flow toward one of the nearest AGN (a Type 2 Seyfert at d=4.2 Mpc). We will measure the density of gas in the torus and its larger-scale surroundings and test chemical (e.g. X-ray Dominated Region or XDR) models for gas around an AGN. The lack of star formation in the nucleus of this galaxy will allow us to use these measurements to uniquely isolate and resolve the impact of the AGN on a galaxy's central gas reservoir. Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei Active galaxies 2022-11-24T00:05:36.000
648 2018.1.01020.S 39 Testing for efficient grain growth in the dust trap around Sz 91 The probably most popular model for giant planet formation is the core accretion scenario. However, this model is facing serious difficulties. One of the most severe challenges for the model certainly is to overcome the radial drift barrier which is supposed to prevent the formation of planetesimals. Particle traps generated by pressure bumps in the disk are one possibility to slow the radial drift and allow planetesimals to form. In recent years we have characterized the transition disk around the young stellar object Sz91. Based on ALMA Band 7 continuum data (of 0.2 arcsec resolution) we found that the mm-sized particles accumulate in a sharp ring radially unresolved. This ring structure might represent a radial particle trap in which planetesimals could form. We here propose to observe this disk in Band 4 and 7 at high resolution to constrain the sharpness of the ring and the particle size distribution. Disks around low-mass stars Disks and planet formation 2019-12-12T18:22:47.000
649 2021.1.01611.S 13 CI and high-J CO emission from jet-impacted clouds in IC5063: cosmic ray vs. shock heating and their impact on X_CO Shocks and cosmic rays (CRs) are dominant pathways of feedback-ISM coupling in jet-driven outflows, that differently affect the molecular gas. Shocks drive hotter, thinner molecular outflows than CRs, requiring lower X_CO factors to provide the outflow mass. To overcome this uncertainty, which can be as high as 1 order of magnitude, we will determine X_CO in the galaxy IC5063 - a prototype for jet-driven outflows - by means of SLED fitting. We request CO(6-5), (7-6), CI(2-1), and HCO+(8-7) data that, combined with previous low-J CO and HCO+ data, will enable us to model the line emission via astrochemical, thermally-balanced radiative transfer calculations using CRs and shocks as heating sources. Once the shock- vs. CR- excited fraction of the clouds is known and X_CO is determined, the molecular mass content of the flow will be found. We will compare molecular and atomic (CI-based) masses to evaluate in which phase does most of the gas get accelerated. With our calculations also providing the cloud density and temperature, we will study how pressure changes associated with the jet passage lead to the evaporation of molecular clouds and to the flow mass loading. Outflows, jets, feedback Active galaxies 2023-05-17T11:27:52.000
650 2017.1.00700.S 13 Fragmentation and binary formation in the AFGL 4176 disk We propose to use the long-baseline capabilities of ALMA Cycle 5 at 1.2mm to resolve and characterise the structure and fragmentation of the best example to date of a disk around a forming O-type star. Our Cycle 1 observations of the AFGL4176 disk, also taken at 1.2mm, show that it is in near-Keplerian rotation, but our physical resolution was limited to ~1250 AU. We propose to observe the CH3CN 13(K)-12(K) lines, which are well-tested disk/kinematical tracers and temperature probes. In addition, we will observe 1.2mm continuum to trace the disk surface density at a resolution of 0.025" or 100AU, which using simulations we show is sufficient to uncover fragments in the disk. These three properties (the surface density, kinematics and temperature) will allow us to carry out a highly-resolved stability analysis of a disk around an O-type star. Further, we will search for fragments in the disk sufficiently massive to lead to companion formation, providing insight into the origin of massive binary systems. Disks around high-mass stars Disks and planet formation 2019-01-24T00:10:30.000
651 2022.1.00999.S 0 Revolutionary insights into the z>7 gas and dust physics Although high-z galaxy sample sizes with FIR line and dust continuum detections have known a boost with ALMA, the characterisation of their gas and dust reservoirs remains elusive. We propose to target five FIR lines ([OIII]52,[NII]122,[OI]145,[CI]370,CO7-6) and the underlying dust continuum in the brightest [CII]-, [OIII]88- and dust-detected z=7.306 galaxy (UVISTA-Y-003). This ambitious program will allow us to unambiguously constrain the gas densities, ionisation parameter, ionising photon escape fraction, molecular gas mass and gas-phase O, C and N abundances. We will gain unprecedented insights into the early metal and dust enrichment, the efficiency of star formation, and the contribution of massive galaxies to cosmic reionisation. The exquisite sampling of the rest-frame 52-370 micron dust SED comes for free, and will enable us - for the first time - to cover the z>7 dust SED peak and to constrain the dust temperature, mass and IR luminosity with high precision. The IR luminosity will be crucial to interpret the IRX-beta diagram; whereas the metal and dust masses will allow us to tie down the dominant dust production sources and the importance of gas accretion and outflows. Starburst galaxies Active galaxies 2024-05-17T10:32:28.000
652 2021.1.00450.S 0 Piercing the Opacity-Limited Envelopes of the Youngest Protostars in Orion The coordinated ALMA (0.87 mm) and VLA (8 mm) survey of 328 protostars in Orion has revealed three extremely young protostars that are irregular, massive (~1 M_sun), compact (R~100 AU), and optically thick at 0.87 mm. These densities imply free fall timescales of ~100 yrs, but the derived properties imply cooling limited contraction over ~2000 yrs. Recently delivered polarization data are giving insights into the role the magnetic field plays to support these objects against collapse. The measured thermal energy is not sufficient to support the cores over a slower contraction, suggesting that there is additional support from rotational and/or turbulent motions. However, no line data exist yet to evalulate possible support mechanisms from rotation or turbulence. Band 3 observations are requested, where the optical depth will be lower, to map the line widths, spatial distribution of 13CO, C17O, C18O, and CN lines, the continuum of the inner envelopes from ~80 - 100 AU, and measure infall signatures. This will reveal the motions of the inner envelopes for the first time and determine the basic energy balance for support, by directly evaluating the turbulence and/or rotational energy. Low-mass star formation ISM and star formation 2024-06-16T23:03:58.000
653 2013.1.01020.S 10 Gas Dissipation in Protoplanetary Disks at the Final Stage of Disk Evolution We propose to investigate the final stage of protoplanetary disk evolution with ALMA. Our tagets (PDS~70, RX~J1604.3$-$2130, IRAS~04125$+$2902, and Sz~91) are weak-line T Tauri stars (WTTS) that have so-called {\it transitional disks}. The large cavities ($r>$20 ~AU) in the central disk-region around these four objects have been imaged at both (sub-)mm and near-infrared (NIR) wavelengths, and this imagery suggests the large-mm-size and small-sub-$\mu$m-size dust grains are dissipated inside the cavity. Among the many transitional disks that have been discovered around classical T Tauri stars (CTTS), these four WTTS systems are likely to be more evolved and close to the epoch of their final stage of disk evolution. We propose to use Band~6 observations at a maximum spatial resolution of 0.$''$18 to measure the amount of gas inside the cavity, in order to obtain observational evidence of gas-decreasing in transitional disks around WTTS. Disks around low-mass stars, Exo-planets Disks and planet formation 2017-01-22T14:04:05.000
654 2022.A.00026.S 10 The state of Betelgeuse after the Great Dimming Betelgeuse's Great Dimming in 2020 almost certainly involved a mass ejection leading to dust formation. This may have partially blocked the light in our direction, but could also have involved intrinsic stellar dimming and the formation of cool surface spots. In 2022, it was recognised that Betelguese had subsequently undergone a change in periodicity. By April this year, it had also reached an historically high optical brightness (~0.0 magn). Thus it may be undergoing an increase in pulsation amplitude generally, possibly pressaging an increase in mass loss rate or a symptom of an internal upheaval. ALMA in its longest baseline configurations can resolve the star and any starspots, as well as the proposed ejected gas and dust. Recognition of the unusual state of Betelgeuse came after the ALMA long-baseline deadline, but there is a need to catch the system in its' current active state. Comparison with pre-dimming band 7 observations will confirm the presence of recently-formed dust and ejected gas, and multi-band mm - sub-mm imaging will probe increasingly deep into the star, relating stellar inhomogeneities such as convection-related local cooling to the recent mass loss. Hypergiants, Evolved stars - Shaping/physical structure Stars and stellar evolution 2024-05-21T07:50:57.000
655 2013.1.00183.S 0 The Pre-Stellar Core Mass Function with Deuterium Chemistry in an Infrared Dark Cloud Similarities between the shapes of the core mass function (CMF) and the stellar initial mass function have been noted, which may reveal a fundamental aspect of the star formation process. However, the relation of these "cores", typically observed via their dust continuum emission, and the pre-stellar cores (PSC) that will actually form stars is unclear. Here we propose to measure the PSC mass function by mapping N2D+(3-2) over a contiguous region of an IRDC that we have already observed in N2H+ with CARMA and in which we have already identified at least two relatively massive N2D+ PSCs with ALMA in Cycle 0. We expect to identify ~75 N2D+ cores, and measure masses via mm continuum emission, mid-infrared extinction and virial methods. We will carry out astrochemical modeling of the cores to estimate deuteration ages, which can help de-bias the observed PSC mass function to obtain the true PSC mass function. We will also study the chemical evolution from PSCs to protostellar cores. Finally, we will measure core-to-core kinematics and compare with simulations of molecular cloud turbulence. Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry ISM and star formation 2017-10-23T00:00:00.000
656 2019.1.01382.S 8 Sub-kiloparsec mapping of the molecular gas in a quintessential merger-driven starburst at z=1.52 We aim to map the spatially-resolved molecular gas distribution using the CO 5-4 line and dust continuum of PACS-787, an archetypal twin-galaxy merger at z=1.52 with extreme star formation rates from Herschel and ALMA. We already have CO measurements with ALMA of two transitions: J=2-1 at 2" resolution (giving total gas mass) and J=5-4 at 0.3-0.4" resolution (gas and dust mass on ~1 kpc scales). These show a merger of two massive gas-rich galaxies separated by 8.6 kpc, a high efficiency of forming stars in both nuclei, and the existence of compact (r ~ 1 kpc), likely counter-rotating disks that may funnel gas inflows to the nuclear regions. With a spatial resolution of 0.04", we will map the structure and kinematics of the two galaxies on scales of ~300 pc. A deep map of the two galaxies at such resolution will allow us to accurately model the two disks, derive their dynamical masses, constrain the L_CO to gas mass conversion factor, establish to which extent these starbursts are driven by higher gas content or higher star formation efficiency (SFE) and explore variations (radial or in clumps) of the SFE, thus shedding light on the physics of starbursts at high redshift. Starburst galaxies Active galaxies 2022-06-09T11:59:29.000
657 2019.2.00068.S 0 The 'Missing Link': Gas Accrection Flows in the Galactic Bar toward the Central Molecular Zone We propose to observe 25 clouds in the Galactic bar with gas temperatures of tens of K and broad lines (>~10km/s) - these clouds are the best candidates for the gas flow that feeds the Central Molecular Zone (CMZ) of our Milky Way. Whereas the CMZ is a well studied region at all wavelengths (including the supermassive black hole Sgr A* and the vigorous star forming region Sgr B2), the streams that feed the CMZ have largely been neglected. Modeling the gas shows that it likely follows x1 and x2 orbits, enforced by the bar potential, with gas accretion at various points and cloud-cloud collision from some dynamical effects like (self-)intersecting orbits and accretion overshooting. We propose to probe these processes by simultaneously observing molecular lines that trace physical parameters such as shocks, turbulence, temperature, ionization etc. The ACA+TP is the perfect telescope for our study as it allows us to probe relatively large regions at molecular clump resolution with adequate sensitivity. The data will form an invaluable grid of cloud properties for improved detailed dynamical models of the inner Galaxy. Galactic centres/nuclei Active galaxies 2024-06-06T21:51:14.000
658 2021.1.00799.S 62 Characterizing the Decline of Massive Protostellar Outbursts The discovery of 3 accretion outbursts in massive protostars over the past 4 years has motivated new hydrodynamic simulations of protostellar accretion. The results suggest that massive stars gain up to 40-60% of their total mass from episodic accretion, with an inverse relation between outburst duration and peak luminosity. All three of the outbursts arose from protostars that power copious hot core line emission, and each event triggered methanol maser flares. Two of the three outbursts (NGC6334I-MM1 and G358.93-0.03-MM1) remain at elevated luminosities after 6 and 2 years, respectively, and tracking their decline is a key observable to constrain future theory. Our primary goal is to continue characterizing the luminosity evolution of these objects by gathering a new epoch of multi-wavelength millimeter continuum and mid-IR images. With ALMA, in addition to comparing the dust continuum light curve with the maser light curve, we will also be able measure whether the thermal line excitation temperatures, physical extent, and velocity structure have altered since the initial peak of the outbursts, which will impact future studies of hot core chemistry. High-mass star formation ISM and star formation 2023-06-24T16:34:00.000
659 2016.1.01299.S 17 Architecture and disk structure in a high-mass protobinary system High-mass stars exhibit a significantly higher multiplicity frequency than low-mass stars, likely reflecting differences in their formation mechanism. Theoretical work suggests that the high-mass binaries might form via the fragmentation of self-gravitational disks or alternative scenarios such as disk-assisted capture. Intriguingly, in recent VLTI/AMBER near-infrared interferometric observations we detected a close high-mass protobinary with a 57mas (approx. 170AU) separation. Around the individual stars we resolve near-infrared excess emission that is likely associated with hot dust in circumstellar disks. We characterised the system with SMA sub-mm interferometry and identified a suite of outflow- and disk/envelope-tracing lines that we would like to resolve now with ALMA 40mas-resolution imaging. Our aim is to resolve the circumbinary disk/envelope, to study the signatures of binary-disk interaction, and to search for the accretion streamers that feed the circumstellar disks. We will image the outflow-launching region and determine the dynamical mass of the central objects, providing a first glimpse into the evolution of high-mass multiple systems during the accretion phase. Disks around high-mass stars Disks and planet formation 2018-08-02T04:51:26.000
660 2019.1.01633.S 12 Gold Standard of Dynamical Mass Estimates for z>6 Quasar Host Galaxies The knowledge of dynamical masses of galaxies is indispensable to put galaxies in an evolutionary context. However, deriving accurate dynamical masses requires significantly resolved measurements of a bright spectral line that are typically not accessible at high redshift. This is why other estimators (~v_disp^2 D) are often employed to put first constraints on dynamical masses in unresolved (or barely resolved) observations, but the implied uncertainties are significant. Out of a sample of 27 quasar host galaxies at z>6 in which bright [CII] emission was detected with ALMA at ~0.2-0.3" resolution, we have identified two galaxies that show large disks with apparently smooth rotation. Using a custom-made Markov Chain Monte Carlo fitting method, these two galaxies are prime targets to obtain accurate dynamical masses through the requested 0.09"(500 pc) and 0.06"(300 pc) [CII] imaging, and thus to test the applicability of low-resolution estimators. These measurements can be directly compared to the central black hole masses in these quasars, to assess how or if their black holes are over-massive compared to local scaling relations. High-z Active Galactic Nuclei (AGN) Active galaxies 2023-01-25T15:41:15.000
661 2019.1.00574.S 14 Caught in the act: disruption of a high-mass disk by anisotropic accretion Disks and outflows play an important role in the formation process of stars of all masses, from low-mass up to the most massive O-type stars. However, the number of clear-cut disks around O-type stars is still very low. We used ALMA to search for disks in six of them, and found 3 candidates to be confirmed with higher resolution. In this proposal we will resolve the disk around G29.96-0.02, a well-known region for which rotating structures were claimed in the past. Our 0.2-arcsec ALMA observations reveal a new and interesting scenario where the disk is not what it was thought to be, and an energetic and collimated outflow plays a dominant role. Due to non-isotropic accretion, the disk plane orientation has changed. This has modified the orientation of the outflow, which is now disrupting the outer parts of the disk. Complex organic molecules, typically found tracing disks in massive stars, appear now to trace the base of the outflow. We find evidence for a possible compact disk (600 au in size) perpendicular to the current outflow axis. With 25-mas resolution (or 120 au) observations, we will search for the real disk in G29.96-0.02 and investigate the disk-outflow interaction. High-mass star formation ISM and star formation 2022-11-16T23:28:14.000
662 2013.1.00032.S 45 AGN feedback and molecular line flux ratios in infrared luminous dusty galaxies We propose molecular line observations of nearby infrared luminous dust/gas-rich galaxies for which the relative energetic importance of AGN and starburst has been quantitatively well-calibrated through previous infrared spectroscopy. Using different feedback from AGNs and starbursts to the surrounding molecular gas, we aim to establish a reliable method to scrutinize optically elusive buried AGNs in dusty galaxies, based on bright molecular line flux ratios at the dust-extinction-free (sub)millimeter wavelength. Our pre-ALMA and ALMA Cycle 0 observations have shown that enhanced HCN emission is empirically an excellent AGN indicator, but its physical origin is unclear. We propose ALMA Cycle 2 observations of these well-calibrated galaxies, at multiple transition lines of HCN/HCO+/HNC, in order to clarify the physical origin (i.e., an HCN abundance enhancement or excitation effect). Our (sub)millimeter energy diagnostic method using bright molecular lines, once established, will have a large potential to understand the interplay between suparmassive blackholes and star-formation in distant infrared luminous galaxies, which are known