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2241. VLA 1.4GHz survey of ECDF-S (DR2)
ID:
ivo://CDS.VizieR/J/ApJS/205/13
Title:
VLA 1.4GHz survey of ECDF-S (DR2)
Short Name:
J/ApJS/205/13
Date:
21 Oct 2021
Publisher:
CDS
Description:
Deep radio observations at 1.4GHz for the Extended Chandra Deep Field South were performed in 2007 June through September and presented in a first data release. The survey was made using six separate pointings of the Very Large Array with over 40hr of observation per pointing. In the current paper, we improve on the data reduction to produce a second data release (DR2) mosaic image. This DR2 image covers an area of about a third of a square degree, reaches a best rms sensitivity of 6uJy, and has a typical sensitivity of 7.4uJy per 2.8" by 1.6" beam. We also present a more comprehensive catalog, including sources down to peak flux densities of five or more times the local rms noise along with information on source sizes and relevant pointing data. We discuss in some detail the consideration of whether sources are resolved under the complication of a radio image created as a mosaic of separate pointings each suffering some degree of bandwidth smearing, and the accurate evaluation of the flux densities of such sources. Finally, the radio morphologies and optical/near-IR counterpart identifications are used to identify 17 likely multiple-component sources and arrive at a catalog of 883 radio sources, which is roughly double the number of sources contained in the first data release.
2242. VLA imaging of IRAS 1 Jy ULIRG sample
ID:
ivo://CDS.VizieR/J/A+A/409/115
Title:
VLA imaging of IRAS 1 Jy ULIRG sample
Short Name:
J/A+A/409/115
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper presents the results of a high resolution radio imaging survey of 83 of the 118 ultraluminous infrared galaxies (ULIRGs) in the IRAS 1Jy ULIRG sample (Kim & Sanders, 1998ApJS..119...41K, Veilleux et al., 2002, Cat. <J/ApJS/143/315>). We have observed these ULIRGs at 15-GHz with the Very Large Array (VLA). We find that ~75% of Seyferts (both type 1 and 2) and LINERs have radio nuclei which are compact at our 150mas resolution. The detection rate of HII nuclei is significantly lower (32%); the detections among these are preferentially HII+LINER/Seyfert composite nuclei. Among ULIRGs with multiple optical or near-IR nuclei our observations detected only one (or no) nucleus; in these the radio detection is typically towards the brightest near-IR nucleus. The compactness of the radio sources, the higher detection rates in AGN-type nuclei than HII nuclei, the preferential detection of nuclei with unresolved point sources in the near-IR, the low soft X-ray to nuclear radio luminosity ratio (arguing against thermal emission powering the radio nuclei), and the lack of correlation between radio power and H{alpha} luminosity, all support an origin of the detected radio nuclei in AGN related activity. This result is especially interesting for LINER ULIRGs for which signatures of AGNs have often been ambiguous in other wavebands. Such a high incidence of AGN would provide, for the first time, a large sample in which to study the interplay between AGN, starbursts, and galaxy mergers.
2243. VLA Low-frequency Sky Survey
ID:
ivo://nasa.heasarc/skyview/vlss
Title:
VLA Low-frequency Sky Survey
Short Name:
VLSS
Date:
07 Mar 2025
Publisher:
NASA/GSFC HEASARC
Description:
The VLA Low-Frequency Sky Survey (VLSS) is a 74 MHz continuum survey covering the entire sky north of -30 degrees declination. Using the VLA in BnA and B-configurations, it will map the entire survey region at a resolution of 80" and with an average rms noise of 0.1 Jy/beam. <p> This version include the data from the VLSS redux which increased the coverage region slightly and substantially improved the data reduction. Details are in the Lane et al. (2012) reference. Provenance: <b>VLSS Team: </b>R.A. Perley, J.J. Condon, W.D. Cotton (NRAO); A.S. Cohen, W.M. Lane (NRC/NRL), N.E. Kassim, T.J.W. Lazio (NRL), W.C. Erickson (UMd). This is a service of NASA HEASARC.
2244. VLA 352MHz image of the Bootes field. I.
ID:
ivo://CDS.VizieR/J/MNRAS/450/1477
Title:
VLA 352MHz image of the Bootes field. I.
Short Name:
J/MNRAS/450/1477
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a 324.5MHz image of the NOAO Bootes field that was made using Very Large Array (VLA) P-band observations. The image has a resolution of 5.6"x5.1", a radius of 2.05 degrees and a central noise of ~0.2mJy/beam. Both the resolution and noise of the image are an order of magnitude better than what was previously available at this frequency and will serve as a valuable addition to the already extensive multiwavelength data that are available for this field. The final source catalogue contains 1370 sources and has a median 325 to 1400MHz spectral index of -0.72. Using a radio colour-colour diagram of the unresolved sources in our catalogue, we identify 33 megahertz peaked-spectrum (MPS) sources. Based on the turnover frequency linear size relation for the gigahertz peaked-spectrum (GPS) and compact steep-spectrum (CSS) sources, we expect that the MPS sources that are compact on scales of tens of milliarcseconds should be young radio loud active galactic nuclei at high (z>2) redshifts. Of the 33 MPS sources, we were able to determine redshifts for 24, with an average redshift of 1.3. Given that five of the sources are at z>2, that the four faint sources for which we could not find redshifts are likely at even higher redshifts and that we could only select sources that are compact on a scale of ~5", there is encouraging evidence that the MPS method can be used to search for high-redshift sources.
2245. VLA rotation measures in the Galactic plane
ID:
ivo://CDS.VizieR/J/ApJ/728/97
Title:
VLA rotation measures in the Galactic plane
Short Name:
J/ApJ/728/97
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have determined 194 Faraday rotation measures (RMs) of polarized extragalactic radio sources using new, multi-channel polarization observations at frequencies around 1.4GHz from the Very Large Array in the Galactic plane at 17{deg}<=l<=63{deg} and 205{deg}<=l<=253{deg}. This catalog fills in gaps in the RM coverage of the Galactic plane between the Canadian Galactic Plane Survey (CGPS; Taylor et al. 2003, Cat. VI/128; Brown et al. 2003, Cat. J/ApJS/145/213) and Southern Galactic Plane Survey (SGPS; Haverkorn et al. 2006ApJS..167..230H; Brown et al. 2007, Cat. J/ApJ/663/258).
2246. VLASS QL Ep.1 Catalog, CIRADA version
ID:
ivo://CDS.VizieR/J/ApJS/255/30
Title:
VLASS QL Ep.1 Catalog, CIRADA version
Short Name:
J/ApJS/255/30
Date:
09 Feb 2022 14:56:38
Publisher:
CDS
Description:
The Very Large Array Sky Survey (VLASS) is observing the entire sky north of -40{deg} in the S-band (2-4GHz), with the highest angular resolution (2.5") of any all-sky radio continuum survey to date. VLASS will cover its entire footprint over three distinct epochs, the first of which has now been observed in full. Based on Quick Look images from this first epoch, we have created a catalog of 1.9x10^6 reliably detected radio components. Due to the limitations of the Quick Look images, component flux densities are underestimated by ~15% at S>3mJy/beam and are often unreliable for fainter components. We use this catalog to perform statistical analyses of the 3GHz radio sky. Comparisons with the Faint Images of the Radio Sky at Twenty cm survey (FIRST) show the typical 1.4-3GHz spectral index to be -0.71. The radio color-color distribution of point and extended components is explored by matching with FIRST and the LOFAR Two Meter Sky Survey. We present the VLASS source counts, dN/dS, which are found to be consistent with previous observations at 1.4 and 3GHz. Resolution improvements over FIRST result in excess power in the VLASS two-point correlation function at angular scales <7", and in 18% of active galactic nuclei associated with a single FIRST component being split into multi-component sources by VLASS.
2247. VLA survey of CDF-S. II.
ID:
ivo://CDS.VizieR/J/ApJS/179/95
Title:
VLA survey of CDF-S. II.
Short Name:
J/ApJS/179/95
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the optical and infrared identifications of the 266 radio sources detected at 20cm with the Very Large Array in the Chandra Deep Field-South. Using deep i-band Advanced Camera for Surveys, R-band Wide Field Imager, K-band SOFI NTT, K-band ISAAC VLT and Spitzer imaging data, we are able to find reliable counterparts for 254 (~95%) VLA sources. Twelve radio sources remain unidentified, and three of them are "empty fields". Using literature and our own data we are able to assign redshifts to 186 (~70%) radio sources: 108 are spectroscopic redshifts and 78 are reliable photometric redshifts. Based on the rest-frame colors and morphological distributions of the host galaxies, we find evidences for a change in the submillijansky radio source population: (1) above ~0.08mJy early-type galaxies are dominating and (2) at flux densities below ~0.08mJy, starburst galaxies become dominant.
2248. VLA survey of CDF-S. III.
ID:
ivo://CDS.VizieR/J/ApJ/698/740
Title:
VLA survey of CDF-S. III.
Short Name:
J/ApJ/698/740
Date:
21 Oct 2021
Publisher:
CDS
Description:
We discuss the X-ray properties of the radio sources detected in a deep 1.4 and 5GHz VLA Radio survey of the Extended Chandra Deep Field-South (E-CDFS). Among the 266 radio sources detected, we find 89 sources (1/3 of the total) with X-ray counterparts in the catalog of the 1Ms exposure of the central 0.08deg^2^ or in the catalog of the 250ks exposure of the 0.3deg^2^ E-CDFS field. For 76 (85%) of these sources, we have spectroscopic or photometric redshifts, and therefore we are able to derive their intrinsic properties from X-ray spectral analysis, namely intrinsic absorption and total X-ray luminosities. We find that the population of submillijansky radio sources with X-ray counterparts is composed of a mix of roughly 1/3 star-forming galaxies and 2/3 active galactic nuclei (AGNs).
2249. VLA Survey of SDSS Stripe 82
ID:
ivo://nasa.heasarc/skyview/stripe82vla
Title:
VLA Survey of SDSS Stripe 82
Short Name:
Stripe82VLA
Date:
07 Mar 2025
Publisher:
NASA/GSFC HEASARC
Description:
This survey is a deep, high resolution radio survey of a relatively small region that has particularly deep coverage in the Sloan Digital Sky Survey. As described in the reference abstract: This is a high-resolution radio survey of the Sloan Digital Sky Survey (SDSS) Southern Equatorial Stripe, a.k.a., Stripe 82. This 1.4 GHz survey was conducted from 2007 to 2009 with the Very Large Array primarily in the A-configuration, with supplemental B-configuration data to increase sensitivity to extended structure. The survey has an angular resolution of 1.8" and achieves a median rms noise of 53 microJy/beam over 92 square degrees. This is the deepest 1.4 GHz survey to achieve this large of an area filling in the phase space between small&amp;deep and large&amp;shallow surveys. <p> The astrometric accuracy of the data is excellent with errors in observed sources of 0.10" in both RA and declination. A comparison with the SDSS DR7 Quasar Catalog confirms that the astrometry is well tied to the optical reference frame with mean offsets of 0.02+/-0.01" in RA and 0.01+/-0.02 in declination. Provenance: TBD. This is a service of NASA HEASARC.
2250. VLA-VIRMOS Deep Field
ID:
ivo://CDS.VizieR/J/A+A/403/857
Title:
VLA-VIRMOS Deep Field
Short Name:
J/A+A/403/857
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have conducted a deep survey (rms noise ~=17{mu}Jy) with the Very Large Array (VLA) at 1.4GHz, with a resolution of 6arcsec, of a 1{deg}^2^ region included in the VIRMOS VLT Deep Survey. In the same field we already have multiband photometry down to I_AB_=25, and spectroscopic observations will be obtained during the VIRMOS VLT survey. The homogeneous sensitivity over the whole field has allowed to derive a complete sample of 1054 radio sources (5{sigma} limit). We give a detailed description of the data reduction and of the analysis of the radio observations, with particular care to the effects of clean bias and bandwidth smearing, and of the methods used to obtain the catalogue of radio sources. To estimate the effect of the resolution bias on our observations we have modelled the effective angular-size distribution of the sources in our sample and we have used this distribution to simulate a sample of radio sources. Finally we present the radio count distribution down to 0.08mJy derived from the catalogue. Our counts are in good agreement with the best fit derived from earlier surveys, and are about 50% higher than the counts in the HDF. The radio count distribution clearly shows, with extremely good statistics, the change in the slope for the sub-mJy radio sources.

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