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851. ALMA continuum fits files of G9.62+0.19
ID:
ivo://CDS.VizieR/J/A+A/626/A36
Title:
ALMA continuum fits files of G9.62+0.19
Short Name:
J/A+A/626/A36
Date:
21 Oct 2021
Publisher:
CDS
Description:
We used Band 7 ALMA observations in full polarisation mode to analyse the polarised dust emission of the massive star forming region G9.62+0.19. We estimated the magnetic field strength via the Davis-Chandrasekhar-Fermi and structure function methods. We resolve several protostellar cores embedded in a bright and dusty filamentary structure. The magnetic field is orientated along the filament and appears perpendicular to the direction of the outflows. The polarisation vectors present ordered patterns and the cores showing polarised emission are less fragmented. We suggest an evolutionary sequence of the magnetic field, and the less evolved hot core exhibits a stronger magnetic field than the more evolved hot core. An average magnetic field strength of the order of 11mG was derived, from which we obtain a low turbulent-to-magnetic energy ratio, indicating that turbulence does not significantly contribute to the stability of the clump. We report a detection of linear polarisation from thermal line emission, probably from methanol or carbon dioxide, and we tentatively compared linear polarisation vectors from our observations with previous linearly polarised OH masers observations.
852. ALMA continuum images of TW Hya
ID:
ivo://CDS.VizieR/J/A+A/648/A33
Title:
ALMA continuum images of TW Hya
Short Name:
J/A+A/648/A33
Date:
08 Feb 2022 14:06:34
Publisher:
CDS
Description:
A key piece of information to understand the origin and role of protoplanetary disk substructures is their dust content. In particular, disk substructures associated with gas pressure bumps can work as dust traps, accumulating grains and reaching the necessary conditions to trigger the streaming instability. In order to shed some light on the origin and role that disk substructures play in planet formation, we aim to characterize the dust content of substructures in the disk of TW Hya. We present Atacama Large Millimeter Array (ALMA) observations of TW Hya at 3.1mm with ~50 milliarcsecond resolution. These new data were combined with archival high angular resolution ALMA observations at 0.87mm, 1.3mm, and 2.1mm. We analyze these multiwavelength data to infer a disk radial profile of the dust surface density, maximum particle size, and slope of the particle size distribution. Most previously known annular substructures in the disk of TW Hya are resolved at the four wavelengths. Inside the inner 3au cavity, the 2.1mm and 3.1mm images show a compact source of free-free emission, likely associated with an ionized jet. Our multiwavelength analysis of the dust emission shows that the maximum particle size in the disk of TW Hya is >1mm. The inner 20au are completely optically thick at all four bands, which results in the data tracing different disk heights at different wavelengths. Coupled with the effects of dust settling, this prevents the derivation of accurate density and grain size estimates in these regions. At r>20au, we find evidence of the accumulation of large dust particles at the position of the bright rings, indicating that these are working as dust traps. The total dust mass in the disk is between 250 and 330M_{sun}_, which represents a gas-to-dust mass ratio between 50 and 70. Our mass measurement is a factor of 4.5-5.9 higher than the mass that one would estimate using the typical assumptions of large demographic surveys. Our results indicate that the ring substructures in TW Hya are ideal locations to trigger the streaming instability and form new generations of planetesimals.
853. ALMA continuum-subtracted datacubes for 48 QSOs
ID:
ivo://CDS.VizieR/J/A+A/630/A59
Title:
ALMA continuum-subtracted datacubes for 48 QSOs
Short Name:
J/A+A/630/A59
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the stacking analysis of a sample of 48 quasi-stellar objects (QSOs) at 4.5<z<7.1 detected by the Atacama Large Millimetre Array (ALMA) in the [CII] {lambda}158um emission line to investigate the presence and the properties of massive, cold outflows associated with broad wings in the [CII] profile. The high sensitivity reached through this analysis allows us to reveal very broad [CII] wings tracing the presence of outflows with velocities in excess of 1000km/s. We find that the luminosity of the broad [CII] emission increases with LAGN, while it does not significantly depend on the star formation rate of the host galaxy, indicating that the central active galactic nucleus (AGN) is the main driving mechanism of the [CII] outflows in these powerful, distant QSOs. From the stack of the ALMA cubes, we derive an average outflow spatial extent of ~3.5kpc. The average atomic neutral mass outflow rate inferred from the stack of the whole sample is dM_out_/dt~100M_{sun}_/yr, while for the most luminous systems it increases to ~200M_{sun}_/yr. The associated outflow kinetic power is about 0.1% of L_AGN_, while the outflow momentum rate is ~L_AGN_/c or lower, suggesting that these outflows are either driven by radiation pressure onto dusty clouds or, alternatively, are driven by the nuclear wind and energy conserving but with low coupling with the interstellar medium. We discuss the implications of the resulting feedback effect on galaxy evolution in the early Universe.
854. ALMA CO observations of 30 Dor
ID:
ivo://CDS.VizieR/J/ApJ/774/73
Title:
ALMA CO observations of 30 Dor
Short Name:
J/ApJ/774/73
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present Atacama Large (sub)Millimeter Array observations of 30 Doradus - the highest resolution view of molecular gas in an extragalactic star formation region to date (~0.4pcx0.6pc). The 30Dor-10 cloud north of R136 was mapped in ^12^CO 2-1, ^13^CO 2-1, C^18^O 2-1, 1.3mm continuum, the H30{alpha} recombination line, and two H_2_CO 3-2 transitions. Most ^12^CO emission is associated with small filaments and clumps (<~1pc, ~10^3^M_{sun}_ at the current resolution). Some clumps are associated with protostars, including "pillars of creation" photoablated by intense radiation from R136. Emission from molecular clouds is often analyzed by decomposition into approximately beam-sized clumps. Such clumps in 30 Doradus follow similar trends in size, linewidth, and surface density to Milky Way clumps. The 30 Doradus clumps have somewhat larger linewidths for a given size than predicted by Larson's scaling relation, consistent with pressure confinement. They extend to a higher surface density at a given size and linewidth compared to clouds studied at 10 pc resolution. These trends are also true of clumps in Galactic infrared-dark clouds; higher resolution observations of both environments are required. Consistency of clump masses calculated from dust continuum, CO, and the virial theorem reveals that the CO abundance in 30 Doradus clumps is not significantly different from the Large Magellanic Cloud mean, but the dust abundance may be reduced by ~2. There are no strong trends in clump properties with distance from R136; dense clumps are not strongly affected by the external radiation field, but there is a modest trend toward lower dense clump filling fraction deeper in the cloud.
855. ALMA CO observations of the system 4C12.50
ID:
ivo://CDS.VizieR/J/A+A/629/A30
Title:
ALMA CO observations of the system 4C12.50
Short Name:
J/A+A/629/A30
Date:
21 Oct 2021
Publisher:
CDS
Description:
The nearby system 4C12.50, also known as IRAS 13451+1217 and PKS 1345+12, is a merger of gas-rich galaxies with infrared and radio activity. It has a perturbed interstellar medium (ISM) and a dense configuration of gas and dust around the nucleus. The radio emission at small (~100pc) and large (~100kpc) scales, as well as the large X-ray cavity in which the system is embedded, are indicative of a jet that could have affected the ISM. We carried out observations of the CO(1-0), (3-2), and (4-3) lines with the Atacama Large Millimeter Array (ALMA) to determine basic properties (i.e., extent, mass, and excitation) of the cold molecular gas in this system, including its already-known wind. The CO emission reveals the presence of gaseous streams related to the merger, which result in a small (4kpc-wide) disk around the western nucleus. The disk reaches a rotational velocity of 200km/s, and has a mass of 3.8(+/-0.4)10^9^M_{sun}_. It is truncated at a gaseous ridge north of the nucleus that is bright in [OIII]. Regions with high-velocity CO emission are seen at signal-to-noise ratios of between 3 and 5 along filaments that radially extend from the nucleus to the ridge and that are bright in [O iii] and stellar emission. A tentative wind detection is also reported in the nucleus and in the disk. The molecular gas speed could be as high as 2200km/s and the total wind mass could be as high as 1.5(+/-0.1)10^9^M_{sun}_. Energetically, it is possible that the jet, assisted by the radiation pressure of the active nucleus or the stars, accelerated clouds inside an expanding bubble.
856. ALMA cube and GMC catalog of J1023+1952
ID:
ivo://CDS.VizieR/J/A+A/645/A97
Title:
ALMA cube and GMC catalog of J1023+1952
Short Name:
J/A+A/645/A97
Date:
21 Oct 2021
Publisher:
CDS
Description:
Tidal dwarf galaxies (TDGs) are gravitationally bound condensations of gas and stars that formed during galaxy interactions. Here we present multi-configuration ALMA observations of J1023+1952, a TDG in the interacting system Arp 94, where we resolved CO(2-1) emission down to giant molecular clouds (GMCs) at 0.64" ~45pc resolution. We find a remarkably high fraction of extended molecular emission (~80-90%), which is filtered out by the interferometer and likely traces diffuse gas. We detect 111 GMCs that give a similar mass spectrum as those in the Milky Way and other nearby galaxies (a truncated power law with a slope of -1.76+/-0.13). We also study Larson's laws over the available dynamic range of GMC properties (~2dex in mass and ~1dex in size): GMCs follow the size-mass relation of the Milky Way, but their velocity dispersion is higher such that the size-linewidth and virial relations appear super-linear, deviating from the canonical values. The global molecular-to-atomic gas ratio is very high (~1) while the CO(2-1)/CO(1-0) ratio is quite low (~0.5), and both quantities vary from north to south. Star formation predominantly takes place in the south of the TDG, where we observe projected offsets between GMCs and young stellar clusters ranging from ~50pc to ~200pc; the largest offsets correspond to the oldest knots, as seen in other galaxies. In the quiescent north, we find more molecular clouds and a higher molecular-to-atomic gas ratio (~1.5); atomic and diffuse molecular gas also have a higher velocity dispersion there. Overall, the organisation of the molecular interstellar medium in this TDG is quite different from other types of galaxies on large scales, but the properties of GMCs seem fairly similar, pointing to near universality of the star-formation process on small scales.
857. ALMA data cubes for HD 101584
ID:
ivo://CDS.VizieR/J/A+A/623/A153
Title:
ALMA data cubes for HD 101584
Short Name:
J/A+A/623/A153
Date:
21 Oct 2021
Publisher:
CDS
Description:
There is growing evidence that red giant evolution is often affected by an interplay with a nearby companion, in some cases taking the form of a common-envelope evolution. We have performed a study of the characteristics of the circumstellar environment of the binary object HD ,101584, that provides information on a likely evolutionary scenario. We have obtained and analyzed ALMA observations, complemented with observations using APEX, of a large number of molecular lines. An analysis of the spectral energy distribution has also been performed. Emissions from 12 molecular species (not counting isotopologues) have been observed, and most of them mapped with angular resolutions in the range 0.1" to 0.6". Four circumstellar components are identified: i) a central compact source of size ~=0.15", ii) an expanding equatorial density enhancement (a flattened density distribution in the plane of the orbit) of size ~=3", iii) a bipolar high-velocity outflow (~=150km/s), and iv) an hourglass structure. The outflow is directed almost along the line of sight. There is evidence of a second bipolar outflow. The mass of the circumstellar gas is ~=0.5[D/1kpc]^2^M_{sun}_, about half of it lies in the equatorial density enhancement. The dust mass is ~=0.01[D/1kpc]^2^M_{sun}_, and a substantial fraction of this is in the form of large-sized, up to 1mm, grains. The estimated kinetic age of the outflow is ~=770[D/1kpc]yr. The kinetic energy and the scalar momentum of the accelerated gas are estimated to be 7x10^45^[D/1kpc]^2^erg and 10^39^[D/1kpc]^2^g.cm/s, respectively. We provide good evidence that the binary system HD 101584 is in a post-common-envelope-evolution phase, that ended before a stellar merger. Isotope ratios combined with stellar mass estimates suggest that the primary star's evolution was terminated already on the first red giant branch (RGB). Most of the energy required to drive the outflowing gas was probably released when material fell towards the companion.
858. ALMA data cubes for IRC+10216
ID:
ivo://CDS.VizieR/J/A+A/629/A146
Title:
ALMA data cubes for IRC+10216
Short Name:
J/A+A/629/A146
Date:
21 Oct 2021
Publisher:
CDS
Description:
Low-mass evolved stars are major contributors to interstellar medium enrichment as a consequence of the intense mass-loss process these stars experience at the end of their lives. The study of the gas in the envelopes surrounding asymptotic giant branch (AGB)stars through observations in the millimetre wavelength range provides information about the history and nature of these molecular factories. Here we present ALMA observations at subarsecond resolution, complemented with IRAM-30m data, of several lines of SiO, SiS, and CS towards the best-studied AGB circumstellar envelope, IRC+10 216. We aim to characterise their spatial distribution and determine their fractional abundances mainly through radiative transfer and chemical modelling. The three species display extended emission with several enhanced emission shells. CS displays the most extended distribution reaching distances up to ap-proximately 20". SiS and SiO emission have similar sizes of approximately 11", but SiS emission is slightly more compact. We have estimated fractional abundances relative to H_2_, which on average are equal to f(SiO)~10^-7^, f(SiS)~10^-6^, and f(CS)~10^-^6 up to the photo-dissociation region. The observations and analysis presented here show evidence that the circumstellar material displays clear deviations from an homogeneous spherical wind, with clumps and low density shells that may allow UV photons from the interstellar medium (ISM) to penetrate deep into the envelope, shifting the photo-dissociation radius inwards. Our chemical model predicts photo-dissociation radii compatible with those derived from the observations, although it is unable to predict abundance variations from the starting radius of the calculations (~10R_{sun}_), which may reflect the simplicity of the model. We conclude that the spatial distribution of the gas proves the episodic and variable nature of the mass loss mechanism of IRC+10 216, on timescales of hundreds of years
859. ALMA datacubes of 6 nearby galaxies
ID:
ivo://CDS.VizieR/J/A+A/641/A24
Title:
ALMA datacubes of 6 nearby galaxies
Short Name:
J/A+A/641/A24
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigated the influence of the random velocity of molecular gas on star-formation activities of 6 nearby galaxies. The physical properties of a molecular cloud, such as temperature and density, influence star-formation activities in the cloud. Additionally, local and turbulent motions of molecules in a cloud may exert substantial pressure against gravitational collapse and thus prevent or reduce star formation in the cloud. However, the influence of gas motion on star-formation activities remains poorly understood. We used data from the Atacama Large Millimeter/submillimeter Array to obtain ^12^CO(J=1-0) flux and velocity dispersion. We then combined these data with 3.6 and 8 micron midinfrared data from the Spitzer Space Telescope to evaluate the effects of gas motion on star-formation activities in several nearby galaxies. We discovered that relatively high velocity dispersion in molecular clouds corresponded with relatively low star-formation activity. Considering the velocity dispersion as an additional parameter, we derived a modified Kennicutt-Schmidt law with a gas surface density power index 0.84 and velocity dispersion power index -0.61.
860. ALMA data for 5 luminous & ultraluminous IR gal.
ID:
ivo://CDS.VizieR/J/ApJ/882/5
Title:
ALMA data for 5 luminous & ultraluminous IR gal.
Short Name:
J/ApJ/882/5
Date:
21 Oct 2021
Publisher:
CDS
Description:
A new analysis of high-resolution data from the Atacama Large Millimeter/submillimeter Array for five luminous or ultraluminous infrared galaxies gives a slope for the Kennicutt-Schmidt (KS) relation equal to 1.74_-0.07_^+0.09^ for gas surface densities {Sigma}_mol_>10^3^M_{sun}_/pc^2^ and an assumed constant CO-to-H2 conversion factor. The velocity dispersion of the CO line, {sigma}_v_, scales approximately as the inverse square root of {Sigma}_mol_, making the empirical gas scale height determined from H~0.5{sigma}^2^/({pi}G{Sigma}_mol_) nearly constant, 150-190pc, over 1.5 orders of magnitude in {Sigma}_mol_. This constancy of H implies that the average midplane density, which is presumably dominated by CO-emitting gas for these extreme star-forming galaxies, scales linearly with the gas surface density, which in turn implies that the gas dynamical rate (the inverse of the freefall time) varies with {Sigma}_mol_^1/2^, thereby explaining most of the super-linear slope in the KS relation. Consistent with these relations, we also find that the mean efficiency of star formation per freefall time is roughly constant, 5%-7%, and the gas depletion time decreases at high {Sigma}_mol_, reaching only ~16Myr at {Sigma}_mol_~10^4^M_{sun}_/pc^2^. The variation of {sigma}_v_ with {Sigma}_mol_ and the constancy of H are in tension with some feedback-driven models, which predict {sigma}_v_ to be more constant and H to be more variable. However, these results are consistent with simulations in which large-scale gravity drives turbulence through a feedback process that maintains an approximately constant Toomre Q instability parameter.

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