- ID:
- ivo://CDS.VizieR/J/ApJS/171/61
- Title:
- All-Sky Survey of Flat-Spectrum Radio Sources
- Short Name:
- J/ApJS/171/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have assembled an 8.4GHz survey of bright, flat-spectrum ({alpha}>-0.5) radio sources with nearly uniform extragalactic (|b|>10{deg}) coverage for sources brighter than S_4.8GHz_=65mJy. The catalog is assembled from existing observations (especially CLASS and the Wright et al., Cat VIII/38, PMN-CA survey), augmented by reprocessing of archival VLA and ATCA data and by new observations to fill in coverage gaps. We refer to this program as CRATES, the Combined Radio All-Sky Targeted Eight GHz Survey. The resulting catalog provides precise positions, subarcsecond structures, and spectral indices for some 11000 sources. We describe the morphology and spectral index distribution of the sample and comment on the survey's power to select several classes of interesting sources, especially high-energy blazars. Comparison of CRATES with other high-frequency surveys also provides unique opportunities for identification of high-power radio sources.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/473/4937
- Title:
- AllWISE ctp to ROSAT/2RXS & XMMSLEW2 catalogs
- Short Name:
- J/MNRAS/473/4937
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We release the AllWISE counterparts and Gaia matches to 106573 and 17665 X-ray sources detected in the ROSAT 2RXS and XMMSL2 surveys with |b|>15{deg}. These are the brightest X-ray sources in the sky, but their position uncertainties and the sparse multi-wavelength coverage until now rendered the identification of their counterparts a demanding task with uncertain results. New all-sky multi-wavelength surveys of sufficient depth, like AllWISE and Gaia, and a new Bayesian statistics based algorithm, NWAY, allow us, for the first time, to provide reliable counterpart associations. NWAY extends previous distance and sky density based association methods and, using one or more priors (e.g. colours, magnitudes), weights the probability that sources from two or more catalogues are simultaneously associated on the basis of their observable characteristics. Here, counterparts have been determined using a Wide-field Infrared Survey Explorer (WISE) colour-magnitude prior. A reference sample of 4524 XMM/Chandra and Swift X-ray sources demonstrates a reliability of 94.7 per cent (2RXS) and 97.4 per cent (XMMSL2). Combining our results with Chandra-COSMOS data, we propose a new separation between stars and AGN in the X-ray/WISE flux-magnitude plane, valid over six orders of magnitude. We also release the NWAY code and its user manual. NWAY was extensively tested with XMM-COSMOS data. Using two different sets of priors, we find an agreement of 96 per cent and 99 per cent with published Likelihood Ratio methods. Our results were achieved faster and without any follow-up visual inspection. With the advent of deep and wide area surveys in X-rays (e.g. SRG/eROSITA, Athena/WFI) and radio (ASKAP/EMU, LOFAR, APERTIF, etc.) NWAY will provide a powerful and reliable counterpart identification tool. See for all the options the Nway manual at https://github.com/JohannesBuchner/nway/raw/master/doc/nway-manual.pdf
- ID:
- ivo://CDS.VizieR/J/ApJ/832/187
- Title:
- ALMA and VLA radio continuum obs. of NGC 6334I
- Short Name:
- J/ApJ/832/187
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Very Large Array and Atacama Large Millimeter/submillimeter Array imaging of the deeply embedded protostellar cluster NGC 6334I from 5cm to 1.3mm at angular resolutions as fine as 0.17" (220au). The dominant hot core MM1 is resolved into seven components at 1.3mm, clustered within a radius of 1000au. Four of the components have brightness temperatures >200K, radii ~300au, minimum luminosities ~10^4^L_{sun}_, and must be centrally heated. We term this new phenomenon a "hot multi-core." Two of these objects also exhibit compact free-free emission at longer wavelengths, consistent with a hypercompact HII region (MM1B) and a jet (MM1D). The spatial kinematics of the water maser emission centered on MM1D are consistent with it being the origin of the high-velocity bipolar molecular outflow seen in CO. The close proximity of MM1B and MM1D (440au) suggests a proto-binary or a transient bound system. Several components of MM1 exhibit steep millimeter spectral energy distributions indicative of either unusual dust spectral properties or time variability. In addition to resolving MM1 and the other hot core (MM2) into multiple components, we detect five new millimeter and two new centimeter sources. Water masers are detected for the first time toward MM4A, confirming its membership in the protocluster. With a 1.3mm brightness temperature of 97K coupled with a lack of thermal molecular line emission, MM4A appears to be a highly optically thick 240L_{sun}_ dust core, possibly tracing a transient stage of massive protostellar evolution. The nature of the strongest water maser source CM2 remains unclear due to its combination of non-thermal radio continuum and lack of dust emission.
- 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.
- 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.
- 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.
