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1741. The Wide-field VLBA Calibrator Survey (WFCS)
ID:
ivo://CDS.VizieR/J/AJ/161/14
Title:
The Wide-field VLBA Calibrator Survey (WFCS)
Short Name:
J/AJ/161/14
Date:
09 Mar 2022
Publisher:
CDS
Description:
This paper presents the results of the largest very long baseline interferometry (VLBI) absolute astrometry campaign to date of 13645 radio source observations with the Very Long Baseline Array. Of these, 7220 have been detected, including 6755 target sources that have never been observed with VLBI before. This makes the present VLBI catalog the largest ever published. The positions of the target sources have been determined with the median uncertainty of 1.7mas, and 15542 images of 7171 sources have been generated. Unlike previous absolute radio astrometry campaigns, observations were made at 4.3 and 7.6GHz simultaneously using a single wide-band receiver. Because of the fine spectral and time resolutions, the field of view was 4'-8'-much greater than the 10"-20" in previous surveys. This made possible the use of input catalogs with low position accuracy and the detection of a compact component in extended sources. Unlike previous absolute astrometry campaigns, both steep- and flat-spectrum sources were observed. The observations were scheduled in the so-called filler mode to fill the gaps between other high-priority programs. This was achieved by the development of the totally automatic scheduling procedure.
1742. The WISH catalogue at 352 MHz
ID:
ivo://CDS.VizieR/VIII/69A
Title:
The WISH catalogue at 352 MHz
Short Name:
VIII/69A
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Westerbork In the Southern Hemishpere (WISH) is a low-frequency (352MHz) radio survey that covers most of the sky between -25 and -15 degrees (1.60sr) at a wavelength of 92cm to a limiting flux density of approximately 18mJy (5sigma). Due to the very low elevation of the observations, the survey has a much lower resolution in declination than in right ascension (54"x54"cosec{delta}). A correlation with the 1.4GHz NVSS (VIII/65) shows that the positional accuracy is less constrained in declination than in right ascension, but there is no significant systematic error. The correlation with the NVSS was also used to construct a sample of faint Ultra Steep Spectrum sources (file uss.dat, table 2 of the paper). This sample is aimed at increasing the number of known high redshift radio galaxies to allow detailed follow-up studies of these massive galaxies and their environments in the early Universe. WISH is a collaboration between the Netherlands Foundation for Research in Astronomy (NFRA/ASTRON) and the Leiden Observatory. Carlos De Breuck, Yuan Tang, Ger de Bruyn, Huub Rottgering, Wil van Breugel, and Roeland Rengelink. For more information, see the WENSS home page at http://www.strw.leidenuniv.nl/wenss/ or contact wenss.people@strw.leidenuniv.nl
1743. The WMAP First Year Source Catalog (WMAP1)
ID:
ivo://CDS.VizieR/J/ApJS/148/97
Title:
The WMAP First Year Source Catalog (WMAP1)
Short Name:
J/ApJS/148/97
Date:
21 Oct 2021
Publisher:
CDS
Description:
The WMAP mission has mapped the full sky to determine the geometry, content, and evolution of the universe. Full-sky maps are made in five microwave frequency bands to separate the temperature anisotropy of the cosmic microwave background (CMB) from foreground emission, including diffuse Galactic emission and Galactic and extragalactic point sources. We define masks that excise regions of high foreground emission, so CMB analyses can be carried out with minimal foreground contamination. We also present maps and spectra of the individual emission components, leading to an improved understanding of Galactic astrophysical processes.
1744. The 64W part of the WRST Survey
ID:
ivo://CDS.VizieR/J/A+AS/73/103
Title:
The 64W part of the WRST Survey
Short Name:
J/A+AS/73/103
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a deep 92cm survey down to 4.5mJy (5{sigma}) carried out with the Westerbork Synthesis Radio Telescope (WSRT) of a field in Lynx, previously observed at three other radio frequencies: 6, 21, and 49cm. The observations, totalising 4*12h were made in the redundancy mode, which makes it possible to achieve a high dynamic range. In total, 384 sources above a 5{sigma} peak flux limit were detected, of which 337 form a complete sample.
1745. The 65W part of the WSRT 21 cm survey in Lynx
ID:
ivo://CDS.VizieR/J/A+AS/71/221
Title:
The 65W part of the WSRT 21 cm survey in Lynx
Short Name:
J/A+AS/71/221
Date:
21 Oct 2021
Publisher:
CDS
Description:
Observations of the field Lynx 3A, obtained at 21cm with 5{sigma} peak flux 85{mu}Jy using the 3-km array of the Westerbork Synthesis Radio Telescope for 16x12h periods during 1984, are reported. Details of the observations and the data reduction are given, and the results are presented in extensive tables and maps. A complete sample of 321 objects within the 0.5{deg} attenuation radius is selected from the 349 objects detected above 85{mu}Jy, and the 1.412GHz source counts down to 100{mu}Jy are found to be in good agreement with VLA surveys of similar depth. The median angular size of sources with total flux density between 350{mu}Jy and 10mJy is shown to be less than 10arcsec.
1746. The XXL Survey. XLI. GMRT XXL-N 610MHz
ID:
ivo://CDS.VizieR/J/A+A/638/A46
Title:
The XXL Survey. XLI. GMRT XXL-N 610MHz
Short Name:
J/A+A/638/A46
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the space density evolution of active galactic nuclei (AGN) using the 610MHz radio survey of the XXL-North field, performed with the Giant Metrewave Radio Telescope (GMRT). The survey covers an area of 30.4deg^2^, with a beamsize of 6.5arcsec. The survey is divided into two parts, one covering an area of 11.9deg^2^ with 1{sigma} rms noise of 200uJy/beam and the other spanning 18.5deg^2^ with rms noise of 45uJy/beam. We extracted the catalog of radio components above 7. The catalog was cross-matched with a multi-wavelength catalog of the XXL-North field (covering about 80% of the radio XXL-North field) using a likelihood ratio method, which determines the counterparts based on their positions and their optical properties. The multi-component sources were matched visually with the aid of a computer code: Multi-Catalog Visual Cross-Matching (MCVCM). A flux density cut above 1mJy selects AGN hosts with a high purity in terms of star formation contamination based on the available source counts. After crossmatching and elimination of observational biases arising from survey incompleteness, the number of remaining sources was 1150. We constructed the rest-frame 1.4GHz radio luminosity functions of these sources using the maximum volume method. This survey allows us to probe luminosities of 23<~log(L1.4GHz[W/Hz])<~28 up to redshifts of z~=2.1. Our results are consistent with the results from the literature in which AGN are comprised of two differently evolving populations, where the high luminosity end of the luminosity functions evolves more strongly than the low-luminosity end.
1747. The Zelenchuk Surveys
ID:
ivo://CDS.VizieR/VIII/49
Title:
The Zelenchuk Surveys
Short Name:
VIII/49
Date:
21 Oct 2021
Publisher:
CDS
Description:
The main catalog contains positions and flux densities for 8511 sources detected in the Zelenchuk 3.9 GHz Survey with declinations between 0 and 14 degrees. The survey was originally published in Amirkhanyan et al. 1989, MIR Publ., Moscow, and contained 8511 sources. The machine version has been cleaned from a few spurious sources by the authors. The angular resolution is (RA x DEC) 70"/cos(decl) x 50'. The survey is 95 percent complete to the limiting flux density 50 mJy, except near the boundaries of the declination zone. A supplementary catalogue of 2946 radio sources observed during Zelenchuk survey at 3.9 GHz in the flux density from 40 to 50 mJy within the declination range 0-14 degrees are presented. ratan is the first results of the deep search survey over a portion of the celestial sphere with the radio telescope RATAN-600 at several cm-wavelengths. The catalogue contains 691 radio sources at 3.9 GHz. Fluxes at the frequencies 3.9, 4.8, 7.5 and 11.2 GHz have been measured for the complete sample of the radio sources from the Zelenchuk survey. The sample contains all sources with S > 200 mJy in the 4-6 degree declination range.
1748. Third catalog of LAT-detected AGNs (3LAC)
ID:
ivo://CDS.VizieR/J/ApJ/810/14
Title:
Third catalog of LAT-detected AGNs (3LAC)
Short Name:
J/ApJ/810/14
Date:
21 Oct 2021
Publisher:
CDS
Description:
The third catalog of active galactic nuclei (AGNs) detected by the Fermi-LAT (3LAC) is presented. It is based on the third Fermi-LAT catalog (3FGL) of sources detected between 100MeV and 300GeV with a Test Statistic greater than 25, between 2008 August 4 and 2012 July 31. The 3LAC includes 1591 AGNs located at high Galactic latitudes (|b|>10{deg}), a 71% increase over the second catalog based on 2 years of data. There are 28 duplicate associations, thus 1563 of the 2192 high-latitude gamma-ray sources of the 3FGL catalog are AGNs. Most of them (98%) are blazars. About half of the newly detected blazars are of unknown type, i.e., they lack spectroscopic information of sufficient quality to determine the strength of their emission lines. Based on their gamma-ray spectral properties, these sources are evenly split between flat-spectrum radio quasars (FSRQs) and BL Lacs. The most abundant detected BL Lacs are of the high-synchrotron-peaked (HSP) type. About 50% of the BL Lacs have no measured redshifts. A few new rare outliers (HSP-FSRQs and high-luminosity HSP BL Lacs) are reported. The general properties of the 3LAC sample confirm previous findings from earlier catalogs. The fraction of 3LAC blazars in the total population of blazars listed in BZCAT remains non-negligible even at the faint ends of the BZCAT-blazar radio, optical, and X-ray flux distributions, which hints that even the faintest known blazars could eventually shine in gamma-rays at LAT-detection levels. The energy-flux distributions of the different blazar populations are in good agreement with extrapolation from earlier catalogs.
1749. Third VLBA calibrator survey: VCS3
ID:
ivo://CDS.VizieR/J/AJ/129/1163
Title:
Third VLBA calibrator survey: VCS3
Short Name:
J/AJ/129/1163
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the third extension to the Very Long Baseline Array (VLBA) Calibrator Survey, containing 360 new sources not previously observed with Very Long Baseline Interferometry (VLBI). The survey, based on three 24 hour VLBA observing sessions, fills the areas on the sky above declination -45{deg} where the calibrator density is less than one source within a 4{deg} radius disk at any given direction. The positions were derived from astrometric analysis of the group delays determined at 2.3 and 8.6GHz frequency bands using the CALC/SOLVE software package. The VCS3 catalog of source positions, plots of correlated flux density versus length of projected baseline, and contour plots and FITS files of naturally weighted CLEAN images, as well as calibrated visibility function files, are available electronically from the Goddard Geodetic VLBI Group.
1750. THOR DR2 source list
ID:
ivo://CDS.VizieR/J/A+A/634/A83
Title:
THOR DR2 source list
Short Name:
J/A+A/634/A83
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Galactic plane has been observed extensively by a large number of Galactic plane surveys from infrared to radio wavelengths at an angular resolution below 40". However, a 21cm line and continuum survey with comparable spatial resolution is lacking. The first half of THOR data (l=14.0{deg}-37.9{deg}, and l=47.1{deg}-51.2{deg}, |b|<=1.25{deg}) has been published in our data release 1 paper. With this data release 2 paper, we publish all the remaining spectral line data and Stokes I continuum data with high angular resolution (10"-40"), including a new HI dataset for the whole THOR survey region (l=14.0{deg}-67.4{deg} and |b|<=1.25{deg}). As we published the results of OH lines and continuum emission elsewhere, we concentrate on the HI analysis in this paper With the Karl G. Jansky Very Large Array (VLA) in C-configuration, we observed a large portion of the first Galactic quadrant, achieving an angular resolution of 40". At L Band, the WIDAR correlator at the VLA was set to cover the 21cm HI line, four OH transitions, a series of Hn{alpha} radio recombination lines (RRLs; n=151 to 186), and eight 128MHz-wide continuum spectral windows (SPWs), simultaneously. We publish all OH and RRL data from the C-configuration observations, and a new HI dataset combining VLA C+D+GBT (VLA D-configuration and GBT data are from the VLA Galactic Plane Survey) for the whole survey. The HI emission shows clear filamentary substructures at negative velocities with low velocity crowding. The emission at positive velocities is more smeared-out, likely due to higher spatial and velocity crowding of structures at the positive velocities. Compared to the spiral arm model of the Milky Way, the atomic gas follows the Sagittarius and Perseus Arm well, but with significant material in the inter-arm regions. With the C-configuration-only HI+continuum data, we produced a HI optical depth map of the THOR areal coverage from 228 absorption spectra with the nearest-neighbor method. With this map, we corrected the HI emission for optical depth, and the derived column density is 38% higher than the column density with optically thin assumption. The total HI mass with optical depth correction in the survey region is 4.7x10^8^M_{sun}_, 31% more than the mass derived assuming the emission is optically thin. If we applied this 31% correction to the whole Milky Way, the total atomic gas mass would be 9.4-10.5x10^9^M_{sun}_. Comparing the HI with existing CO data, we find a significant increase in the atomic-to-molecular gas ratio from the spiral arms to the inter-arm regions. The high-sensitivity and resolution THOR HI dataset provides an important new window on the physical and kinematic properties of gas in the inner Galaxy. Although the optical depth we derive is a lower limit, our study shows that the optical depth correction is significant for Hi column density and mass estimation. Together with the OH, RRL and continuum emission from the THOR survey, these new HI data provide the basis for high-angular-resolution studies of the interstellar medium (ISM) in different phases.