- 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.
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- 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.
- 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.
- 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
- ID:
- ivo://CDS.VizieR/J/A+A/605/A116
- Title:
- ALMA FITS cubes of CO(1-0) and CO(2-1)
- Short Name:
- J/A+A/605/A116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our goal is to characterize the intermediate age, detached shell carbon star U Antliae morphologically and physically in order to study the mass-loss evolution after a possible thermal pulse. High spatial resolution ALMA observations of unprecedented quality in thermal CO lines allow us to derive first critical spatial and temporal scales and constrain modeling effects to estimate mass-loss rates for both the present day as well as the ejection period of the detached shell. The detached shell is remarkably thin, overall spherically symmetric, and shows a barely resolved filamentary substructure possibly caused by instabilities in the interaction zone of winds with different outflow velocities. The expansion age of the detached shell is of the order of 2700 years and its overall width indicates a high expansion-velocity and high mass-loss period of only a few hundred years at an average mass-loss rate of ~10^-5^M_{sun}_/yr. The post-high-mass-loss-rate-epoch evolution of U Ant shows a significant decline to a substantially lower gas expansion velocity and a mass-loss rate amounting to 4x10^-8^M_{sun}_/yr, at present being consistent with evolutionary changes as predicted for the period between thermal pulses.
- ID:
- ivo://CDS.VizieR/J/A+A/597/A41
- Title:
- ALMA Frontier Fields Survey. I.
- Short Name:
- J/A+A/597/A41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Dusty star-forming galaxies are among the most prodigious systems at high redshift (z>1), characterized by high star-formation rates and huge dust reservoirs. The bright end of this population has been well characterized in recent years, but considerable uncertainties remain for fainter dusty star-forming galaxies, which are responsible for the bulk of star formation at high redshift and thus play a key role in galaxy growth and evolution. In this first paper of our series, we describe our methods for finding high redshift faint dusty galaxies using millimeter observations with ALMA. We obtained ALMA 1.1mm mosaic images for three strong-lensing galaxy clusters from the Frontier Fields Survey, which constitute some of the best studied gravitational lenses to date. The ~2'x2' mosaics overlap with the deep HST WFC3/IR footprints and encompass the high magnification regions of each cluster for maximum intrinsic source sensitivity. The combination of extremely high ALMA sensitivity and the magnification power of these clusters allows us to systematically probe the sub-mJy population of dusty star-forming galaxies over a large surveyed area. We present a description of the reduction and analysis of the ALMA continuum observations for the galaxy clusters Abell 2744 (z=0.308), MACS J0416.1-2403 (z=0.396) and MACS J1149.5+2223 (z=0.543), for which we reach observed rms sensitivities of 55, 59 and 71uJy/beam respectively. We detect 12 dusty star-forming galaxies at S/N>=5.0 across the three clusters, all of them presenting coincidence with near-infrared detected counterparts in the HST images. None of the sources fall close to the lensing caustics, thus they are not strongly lensed. The observed 1.1mm flux densities for the total sample of galaxies range from 0.41 to 2.82mJy, with observed effective radii spanning <~0.05" to 0.37"+/-0.21". The lensing-corrected sizes of the detected sources appear to be in the same range as those measured in brighter samples, albeit with possibly larger dispersion.
- ID:
- ivo://CDS.VizieR/J/A+A/633/A160
- Title:
- ALMA Frontier Fields Survey. V.
- Short Name:
- J/A+A/633/A160
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hubble Frontier Fields offer an exceptionally deep window into the high-redshift universe, covering a substantially larger area than the Hubble Ultra-Deep field at low magnification and probing 1-2mags deeper in exceptional high-magnification regions. This unique parameter space, coupled with the exceptional multi-wavelength ancillary data, can facilitate for useful insights into distant galaxy populations. We aim to leverage Atacama Large Millimetre Array (ALMA) band 6 (~263GHz) mosaics in the central portions of five Frontier Fields to characterize the infrared (IR) properties of 1582 ultraviolet (UV)-selected Lyman-Break Galaxies (LBGs) at redshifts of z~2-8. We investigated individual and stacked fluxes and IR excess (IRX) values of the LBG sample as functions of stellar mass (M_star), redshift, UV luminosity and slope {beta}, and lensing magnification. LBG samples were derived from color-selection and photometric redshift estimation with Hubble Space Telescope photometry. Spectral energy distributions (SED)-templates were fit to obtain luminosities, stellar masses, and star formation rates for the LBG candidates. We obtained individual IR flux and IRX estimates, as well as stacked averages, using both ALMA images and u-v visibilities. Two (2) LBG candidates were individually detected above a significance of 4.1-sigma, while stacked samples of the remaining LBG candidates yielded no significant detections. We investigated our detections and upper limits in the context of the IRX-M_star and IRX-{beta} relations, probing at least one dex lower in stellar mass than past studies have done. Our upper limits exclude substantial portions of parameter space and they are sufficiently deep in a handful of cases to create mild tension with the typically assumed attenuation and consensus relations. We observe a clear and smooth trend between M* and {beta}, which extends to low masses and blue (low) {beta} values, consistent with expectations from previous works.
- ID:
- ivo://CDS.VizieR/J/A+A/641/A97
- Title:
- ALMA Magellanic Bridge A molecular clouds
- Short Name:
- J/A+A/641/A97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Magellanic Bridge is a tidal feature located between both Magellanic Clouds, containing young stars formed in situ. Its proximity allows high-resolution studies of molecular gas, dust and star formation in a tidal, low metallicity environment. Our goal is to characterize gas and dust emission in Magellanic Bridge A, the source with the highest 870um excess of emission found in single dish surveys. Using the ALMA telescope including the Morita Array, we mapped with sub-parsec resolution a 3arcmin, field of view centered on the Magellanic Bridge A molecular cloud, in 1.3mm continuum emission and ^12^CO(2-1 line emission. This region was also mapped in continuum at 870um and in ^12^CO(2-1) line emission at ~6pc resolution with the APEX telescope. To study its dust properties, we also use archival Herschel and Spitzer data. We combine the ALMA and APEX ^12^CO(2-1) line cubes to study the molecular gas emission. Magallanic Bridge A breaks up into two distinct molecular clouds in dust and ^12^CO(2-1) emission, which we call North and South. Dust emission in the North source, according to our best parameters from fitting the far-infrared fluxes, is ~3K colder than in the South source in correspondence to its less developed star formation. Both dust sources present large submillimeter excesses in LABOCA data: according to our best fits the excess over the modified blackbody (MBB) fit to the Spitzer/Herschel continuum is E(870um)~7 and E(870um)~3 for the North and South sources respectively. Nonetheless, we do not detect the corresponding 1.3mm continuum with ALMA. Our limits are compatible with the extrapolation of the MBB fits and therefore we cannot independently confirm the excess at this longer wavelength. The ^12^CO(2-1) emission is concentrated in two parsec-sized clouds with virial masses around 400 and 700M_{sun}_ each. Their bulk volume densities are n(H_2_)~0.7-2.6x10^3^cm^-3^, larger than typical bulk densities of Galactic molecular clouds. The ^12^CO luminosity to H_2_ mass conversion factor {alpha}_CO_ is 6.5 and 15.3M_{sun}_/(K.(km/s)pc^2^) for the North and South clouds, calculated using their respective virial masses and ^12^CO(2-1) luminosities. Gas mass estimates from our MBB fits to dust emission yields masses M~1.3x10^3^M_{sun}_ and 2.9x10^3^M_{sun}_ for North and South respectively, a factor of ~4 larger than the virial masses we infer from ^12^CO.
- ID:
- ivo://CDS.VizieR/J/A+A/615/A94
- Title:
- ALMA massive protocluster gas clumps maps
- Short Name:
- J/A+A/615/A94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Fragmentation of massive dense molecular clouds is the starting point in the formation of rich clusters and massive stars. Theory and numerical simulations indicate that the population of the fragments (number, mass, diameter, separation) resulting from the gravitational collapse of such clumps is probably regulated by the balance between the magnetic field and the other competitors of self-gravity, in particular turbulence and protostellar feedback. We have observed 11 massive, dense and young star-forming clumps with the Atacama Large Millimeter Array (ALMA) in the thermal dust continuum emission at 1mm with an angular resolution of 0.25 arcseconds with the aim of determining their population of fragments.
- ID:
- ivo://CDS.VizieR/J/ApJS/256/30
- Title:
- ALMA 1.33mm images of 10 FU Orionis-type stars
- Short Name:
- J/ApJS/256/30
- Date:
- 03 Mar 2022
- Publisher:
- CDS
- Description:
- The FU Orionis-type objects (FUors) are low-mass pre-main-sequence stars undergoing a temporary but significant increase of mass accretion rate from the circumstellar disk onto the protostar. It is not yet clear what triggers the accretion bursts and whether the disks of FUors are in any way different from the disks of nonbursting young stellar objects. Motivated by this, we conducted a 1.3mm continuum survey of 10 FUors and FUor-like objects with ALMA, using both the 7m array and the 12m array in two different configurations to recover emission at the widest possible range of spatial scales. We detected all targeted sources and several nearby objects as well. To constrain the disk structure, we fit the data with models of increasing complexity from 2D Gaussian to radiative transfer, enabling comparison with other samples modeled in a similar way. The radiative transfer modeling gives disk masses that are significantly larger than what is obtained from the measured millimeter fluxes assuming optically thin emission, suggesting that the FUor disks are optically thick at this wavelength. In comparison with samples of regular class II and class I objects, the disks of FUors are typically a factor of 2.9-4.4 more massive and a factor of 1.5-4.7 smaller in size. A significant fraction of them (65%-70%) may be gravitationally unstable.