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17061. VLA Goulds Belt Survey Serpens Region Source Catalog
ID:
ivo://nasa.heasarc/vlagbsser
Title:
VLA Goulds Belt Survey Serpens Region Source Catalog
Short Name:
VLAGBSSER
Date:
18 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
This table contains results from a deep (~17 µJy) radio continuum observations of the Serpens molecular cloud, the Serpens south cluster, and the W40 region that were obtained using the Jansky Very Large Array (JVLA) in its A configuration. The authors detected a total of 146 sources, 29 of which are young stellar objects (YSOs), 2 of which are BV stars, and 5 more of which are associated with phenomena related to YSOs. Based on their radio variability and spectral index, the authors propose that about 16 of the remaining 110 unclassified sources are also YSOs. For approximately 65% of the known YSOs detected here as radio sources, the emission is most likely non-thermal and related to stellar coronal activity. As also recently observed in Ophiuchus, this sample of YSOs with X-ray counterparts lies below the fiducial Guedel & Benz (1993, ApJ, 405, L63) relation. In the reference paper, the authors analyze the proper motions of nine sources in the W40 region, thus allowing them to better constrain the membership of the radio sources in the region. The Serpens molecular cloud and the Serpens South cluster were observed in the same observing sessions on three different epochs (2011 June 17, July 19, and September 12 UT), using 25 and 4 pointings, respectively, with the JVLA at 4.5 and 4.5GHz. The W40 region, on the other hand, was only observed on two epochs (2011 June 17 and July 16), using 13 pointings. The details of the observations are listed in Table 1 of the reference paper. The authors adopted the same criteria as Dzib et al. (2013, ApJ, 775, 63) to consider a detection as firm. For new sources, i.e., those without reported counterparts in the literature, they considered 5-sigma detections, where sigma is the rms noise of the area around the source. For known sources with counterparts in the literature, on the other hand, they included 4-sigma detections. According to these criteria, they detected 94 sources in the Serpens molecular cloud, 41 in the W40 region, and 8 in the Serpens South cluster, for a total of 143 detections. Out of the 143 sources, 69 are new detections (see Section 3.2 of the reference paper). GBS-VLA source positions were compared with source positions from X-ray, optical, near-IR, mid-IR, and radio catalogs. GBS-VLA sources were considered to have a counterpart at another wavelength when the positional coincidences were better than the combined uncertainties of the two data sets. These were about 1 arcsecond for the IR catalogs. For the X-ray and radio catalogs it depended on the instrument and its configuration. The search was done in SIMBAD and included all the major catalogs. The authors also accessed the lists with all YSOs in the c2d-GB clouds compiled by Dunham et al.(2013, AJ, 145, 94) and L.E. Allen et al. (2015, in preparation). In total, 354 c2d-GB sources lie inside the regions observed by the present survey. In order to find their radio counterparts, the authors imaged regions of 64 pixels in each dimension, centered in the c2d-GB positions, and combining accordingly with each region, the three or two epochs. For this search, they only used the field whose phase center was closest to the source. Three additional radio sources were found in Serpens South in this pursuit, increasing the number of the radio detections to 146. This table was created by the HEASARC in October 2015 based on electronic versions of Tables 2, 3 and 6 from the reference paper, which were obtained from the CDS (Catalog J/ApJ/805/9 files table2.dat, table3.dat and table6.dat). This is a service provided by NASA HEASARC .
17062. VLA Goulds Belt Survey Taurus-Auriga Complex Source Catalog
ID:
ivo://nasa.heasarc/vlagbstau
Title:
VLA Goulds Belt Survey Taurus-Auriga Complex Source Catalog
Short Name:
VLAGBSTAU
Date:
18 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
This table contains results from a multi-epoch radio study of the Taurus-Auriga complex made with the Karl G. Jansky Very Large Array (JVLA) at frequencies of 4.5 GHz and 7.5 GHz. A total of 610 sources were detected, 59 of which are related to young stellar objects (YSOs) and 18 to field stars. The properties of 56% of the young stars are compatible with non-thermal radio emission. The authors also show that the radio emission of more evolved YSOs tends to be more non-thermal in origin and, in general, that their radio properties are compatible with those found in other star-forming regions. By comparing their results with previously reported X-ray observations, the authors noticed that YSOs in Taurus-Auriga follow a Guedel-Benz relation with a scaling factor, kappa, of 0.03, as they previously suggested for other regions of star formation. In general, YSOs in Taurus-Auriga and in all the previous studied regions seem to follow this relation with a dispersion of ~1 dex. Finally, the authors propose that most of the remaining sources are related with extragalactic objects but provide a list of 46 unidentified radio sources whose radio properties are compatible with a YSO nature (identified in this implementation of their catalog by values for the parameter radio_yso_flag of 'Y'). The observations were obtained with the JVLA of the National Radio Astronomy Observatory (NRAO) in its B and BnA configuration. Two frequency sub-bands, each 1 GHz wide, and centered at 4.5 and 7.5 GHz, respectively, were recorded simultaneously. The observations were obtained in three different time periods (February 25/26/28 to March 6, April 12/17/20/25, and April 30 to May 1/5/14/22, all in 2011) typically separated from one another by a month: see Table 1 of the reference paper for more details. For their study, the authors observed 127 different target fields distributed across the cloud complex (Figure 1 of the reference paper). The fields were chosen to cover previously known YSOs. In 33 of those fields, the authors could observe more than one YSO target, while in the remaining 94 fields, only one YSO was targeted. In most cases, the infrared evolutionary class (i.e., Classes I, II, or III) or T Tauri evolutionary status (classical or weak line) of the targeted sources was known from the literature. The final images covered circular areas of 8.8 and 14.3 arcminutes in diameter, for the 7.5 and 4.5 GHz sub-bands, respectively, and were corrected for the effects of the position-dependent primary beam response. The noise levels reached for each individual observation was about ~40 µJy and ~30 µJy, at 4.5 GHz and7.5 GHz, respectively. The visibilities of the three, or two, observations obtained for each field were concatenated to produce a new image with a lower noise level (of about ~25 µJy at 4.5 GHz and ~18 µJy at 7.5 GHz). The angular resolution of ~1 arcsecond (see the synthesized beam sizes in Table 1 of the reference paper) allows an uncertainty in position of ~0.1 arcseconds or better. In the observed area, there are a total of 196 known YSOs.The first step was the identification of radio sources in the observed fields. The authors follow the procedure and criteria presented by Dzib et al. (2013, ApJ, 775, 63) who consider a detection as firm if the sources have a flux larger than 4 times the noise level and there is a counterpart known at another wavelength, else they require a flux which is 5 times the noise level. The identification was done using the images corresponding to the concatenation of the observed epochs, which provides the highest sensitivity. From this, a total of 609 sources were detected. Of these sources, 215 were only detected in the 4.5 GHz sub-band, while six were only detected in the 7.5 GHz sub-band. The remaining 388 sources were detected in both sub-bands. The authors searched the literature for previous radio detections, and for counterparts at X-ray, optical, near-infrared, and mid-infrared wavelengths. The search was done using SIMBAD, and accessed all the major catalogs. They considered a radio source to be associated with a counterpart at another wavelength if the separation between the two was below the combined uncertainties of the two data sets. This was about 1.0 arcsecond for the optical and infrared catalogs, but could be significantly larger for some of the radio catalogs (for instance, the NVSS has a positional uncertainty of about 5 arcseconds). They found that only 120 of the sources detected here had previously been reported at radio wavelengths, while the other 491 are new radio detections. On the other hand, the authors found a total of 270 counterparts at other wavelengths. In the literature, 18 are classified as field stars, 49 as extragalactic, 1 is classified as either a star or an extragalactic source in different surveys, 49 are classified as YSOs, 11 are classified as either YSO and extragalactic, and the remaining 143 sources are unclassified. Note that 56 sources were previously known at radio wavelengths but do not have known counterparts at other frequencies. As a consequence, the number of sources that were previously known (at any frequency) is 327, while 284 of the sources in this sample are reported here for the first time. This table was created by the HEASARC in July 2015 based on electronic versions of Tables 1, 4 and 5 from the reference paper, which were obtained from the ApJ web site. This is a service provided by NASA HEASARC .
17063. VLA Hubble Deep Field 20-cm Source Catalog
ID:
ivo://nasa.heasarc/vlahdf20cm
Title:
VLA Hubble Deep Field 20-cm Source Catalog
Short Name:
VLAHDF20CM
Date:
18 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
The authors have conducted a deep radio survey with the Very Large Array (VLA) at 1.4 GHz of a region containing the Hubble Deep Field (HDF). This survey overlaps previous observations at 8.5 GHz allowing them to investigate the radio spectral properties of microJansky sources to flux densities greater than 40 µJy (µJy) at 1.4 GHz and greater than 8 uJy at 8.5 GHz. A total of 371 sources have been catalogued at 1.4 GHz as part of a complete sample within 20 arcminutes of the HDF. The differential source count for this region is only marginally sub-Euclidean and is given by n(S) = (8.3 +/- 0.4) S^(-2.4 +/- 0.1) sr<sup>-1</sup> Jy<sup>-1</sup>. Above about 100 uJy the radio source count is systematically lower in the HDF as compared to other fields. The authors conclude that there is clustering in this radio sample on size scales of 1 to 40 arcminutes. The 1.4 GHz-selected sample shows that the radio spectral indices are preferentially steep (mean spectral index of 0.85) and that the sources are moderately extended with average angular size Theta = 1.8". Optical identification with disk-type systems at z ~ 0.1 - 1 suggests that synchrotron emission, produced by supernovae remnants, is powering the radio emission in the majority of sources. In 1996 November, the authors observed a field centered on the Hubble Deep Field (RA, Dec (J2000.0) = (12<sup>h</sup> 36<sup>m</sup> 49.4<sup>s</sup>, 62<sup>o</sup> 12' 58.00") for a total of 50 hours at 20 cm in the A configuration of the VLA. They reached an rms noise level near the center of the field of 7.5 uJy. They adopted 40 uJy as the formal completeness limit over the entire 1 degree field in their untapered naturally weighted 2 arcseconds image. The authors identified 314 sources within 20 arcminutes of the field center (20% power contour). They found 57 additional sources within this same region (presumably resolved at 2" resolution) in lower resolution (3.5 and 6") tapered images above completeness levels of 50 uJy at 3.5" resolution and 75 uJy at 6" resolution, making a grand total of 371 radio sources detected at 1.4 GHz within 20 arcminutes of the phase center of the field. This table was created by the HEASARC in June 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/533/611">CDS Catalog J/ApJ/533/611</a> file table2.dat. This is a service provided by NASA HEASARC .
17064. VLA Images of Extragalactic Objects
ID:
ivo://CDS.VizieR/J/ApJS/124/285
Title:
VLA Images of Extragalactic Objects
Short Name:
J/ApJS/124/285
Date:
21 Oct 2021
Publisher:
CDS
Description:
Maps of 212 extragalactic radio sources at 4.9 GHz are shown in Stokes I along with linear polarization vectors. The objects have a declination range of 0 degrees to -35 degrees and were chosen from the Hewitt & Burbidge quasar catalog with a spectral index less than -0.5 and the NVSS survey with a minimum 1.4 GHz flux density greater than 300 mJy. The observations were made with the Very Large Array in its B configuration, and the images have a typical resolution of 2 arcseconds. One hundred ninety-five objects were resolved; 108 of the sources are quasars, and another 51 have been identified as galaxies.
17065. 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.
17066. VLA imaging of obscured WISE+NVSS QSOs
ID:
ivo://CDS.VizieR/J/ApJ/896/18
Title:
VLA imaging of obscured WISE+NVSS QSOs
Short Name:
J/ApJ/896/18
Date:
07 Mar 2022 07:27:35
Publisher:
CDS
Description:
We present new subarcsecond-resolution Karl G. Jansky Very Large Array (VLA) imaging at 10GHz of 155 ultraluminous (Lbol~10^11.7^-10^14.2^L_{sun}_) and heavily obscured quasars with redshifts z~0.4-3. The sample was selected to have extremely red mid-infrared-optical color ratios based on data from the Wide-Field Infrared Survey Explorer (WISE) along with a detection of bright, unresolved radio emission from the NRAO VLA Sky Survey (NVSS) or Faint Images of the Radio Sky at Twenty cm Survey. Our high-resolution VLA observations have revealed that the majority of the sources in our sample (93 out of 155) are compact on angular scales <0.2 (<=1.7kpc at z~2). The radio luminosities, linear extents, and lobe pressures of our sources are similar to young radio active galactic nuclei (e.g., gigahertz-peaked spectrum [GPS] and compact steep-spectrum [CSS] sources), but their space density is considerably lower. Application of a simple adiabatic lobe expansion model suggests relatively young dynamical ages (~10^4-7yr^), relatively high ambient ISM densities (~1-10^4^cm^-3^), and modest lobe expansion speeds (~30-10000km/s). Thus, we find our sources to be consistent with a population of newly triggered, young jets caught in a unique evolutionary stage in which they still reside within the dense gas reservoirs of their hosts. Based on their radio luminosity function and dynamical ages, we estimate that only ~20% of classical large-scale FR I/II radio galaxies could have evolved directly from these objects. We speculate that the WISE-NVSS sources might first become GPS or CSS sources, of which some might ultimately evolve into larger radio galaxies.
17067. VLA Lockman Hole 3-GHz Radio Source Catalog
ID:
ivo://nasa.heasarc/vlalhn3ghz
Title:
VLA Lockman Hole 3-GHz Radio Source Catalog
Short Name:
VLALHN3GHZ
Date:
18 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
This table is from the second of two papers describing the observations and source catalogs derived from sensitive 3-GHz images of the Lockman Hole North using the Karl G. Jansky Very Large Array (VLA). In their paper, the authors describe the reduction and cataloguing process, which yielded an image with 8-arcsecond resolution and instrumental noise of sigma&lt;sub&gt;n&lt;/sub&gt; = 1.01 &micro;Jy/beam (&micro;Jy/beam) rms (before primary beam corrections) and a catalog of 558 sources detected above 5 * sigma&lt;sub&gt;n&lt;/sub&gt;. The authors also include details of how they estimate source spectral indices across the 2-GHz VLA bandwidth, finding a median index of -0.76 +/- 0.04. Stacking of source spectra reveals a flattening of spectral index with decreasing flux density. In the reference paper, the authors present a source count derived from the catalog. They show a traditional count estimate compared with a completely independent estimate made via a P(D) confusion analysis, and find very good agreement. Cross-matches of the catalog with X-ray, optical, infrared, radio, and redshift catalogs are also presented. The X-ray, optical and infrared data, as well as AGN selection criteria allow them to classify 10% as radio-loud AGN, 28% as radio-quiet AGN, and 58% as star-forming galaxies, with only 4% unclassified. Observations were made with the VLA in the C configuration at S band, with a frequency range of 2 to 4GHz, with a total of roughly 50 hours of on-source time in 2012. The HEASARC has converted the radio and IR flux density units from those given in the original table (&micro;Jy and &micro;Jy/beam) to its standard units for radio flux densities (mJy and mJy/beam). This table was created by the HEASARC in April 2017 based on &lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/462/2934"&gt;CDS Catalog J/MNRAS/462/2934&lt;/a&gt; files cat3ghz.dat and catcrx.dat. This is a service provided by NASA HEASARC .
17068. VLA Lockman Hole 1400-MHz Radio Source Catalog
ID:
ivo://nasa.heasarc/vlalh1400m
Title:
VLA Lockman Hole 1400-MHz Radio Source Catalog
Short Name:
VLALH1400M
Date:
18 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
In the run-up to routine observations with the upcoming generation of radio facilities, the nature of the sub-mJy radio population has been hotly debated. In this paper, the authors describe multi-frequency data designed to probe the emission mechanism that dominates in these faint radio sources. Their analysis is based on observations of the Lockman Hole (LH) using the Giant Metrewave Radio Telescope (GMRT) near Pune, India - the deepest 610-MHz imaging yet reported - together with 1.4-GHz imaging from the Very Large Array (VLA), which are well matched in resolution and sensitivity to the GMRT data: sigma&lt;sub&gt;610MHz&lt;/sub&gt; ~ 15 &micro;Jy/beam (&micro;Jy/beam), sigma}&lt;sub&gt;1.4GHz&lt;/sub&gt; ~ 6 &micro;Jy/beam, and full width at half-maximum (FWHM) ~ 5 arcseconds. The GMRT and VLA data are cross-matched to obtain the radio spectral indices for the faint radio emitters. During six 12-hr sessions in 2006 February and July, the authors obtained data at 610 MHz for three pointings (FWHM ~ 43 arcminutes) in the LH (see Table 1 of the reference paper for full details), separated by 11 arcminutes (the LOCKMAN-E, LOCK-3 and LHEX-4 fields), typically with 28 of the 30 antennas that comprise the GMRT. The total integration time in each field, after overheads, was 16 hr. The final image had a noise level in the central 100 arcmin&lt;sup&gt;2&lt;/sup&gt; of 14.7 &micro;Jy/beam, the deepest map reported at 610 MHz as of the date of publication, despite the modest integration time. New and archival data were obtained at the same three positions using the National Radio Astronomy Observatory&#39;s VLA, largely in its B configuration. This table contains 1450 sources found in the LH field at 1400 MHz by the VLA. For 17 of the sources which have multiple components, the 29 individual components are listed as well. Thus, the final table contains 1479 (1450 + 29) entries. Source extraction was based on criteria of peak brightness &gt; 5 times the local rms and integrated flux density &gt; 3 times the local rms. This table was created by the HEASARC in February 2012 based on &lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/397/281"&gt;CDS Catalog J/MNRAS/397/281&lt;/a&gt; file table4.dat. This is a service provided by NASA HEASARC .
17069. VLA Low-Frequency Sky Survey Redux Source Catalog
ID:
ivo://nasa.heasarc/vlssr
Title:
VLA Low-Frequency Sky Survey Redux Source Catalog
Short Name:
VLSSR
Date:
18 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
The Very Large Array (VLA) Low-Frequency Sky Survey (VLSS: see Cohen et al. 2007, AJ, 134, 1245) covers 95% of the 3 pi sr of sky area above -30 degrees Declination at most RAs (complete above -10 degrees Declination, while in some areas data are available down to Declinations of -36 degrees) at a frequency of 74 MHz, a resolution of 80&quot;, and an average rms map sensitivity of sigma ~ 0.130 Jy/beam. The survey was intended to serve as a low-frequency counterpart to the National Radio Astronomy Observatory (NRAO)-VLA Sky Survey (NVSS) at 1400 MHz, allowing spectral information to be compiled for statistical samples of sources. It also provides a low-frequency sky model. In their 2012 and 2014 reference papers, the authors present the details of improvements to data processing and analysis which were used for a re-reduction of the VLSS data, which they dub the VLSS redux or VLSSr. They used the VLSS catalogue as a sky model to correct the ionospheric distortions in the data and create a new set of sky maps and corresponding catalog at 73.8 MHz. The VLSS Redux (VLSSr) has a resolution of 75&quot;, and an average map rms noise level of sigma ~ 0.1 Jy beam&lt;sup&gt;-1&lt;/sup&gt;. The clean bias is 0.66 x sigma and the theoretical largest angular size is 36 arcminutes. Six previously unimaged fields are included in the VLSSr, which has an unbroken sky coverage over 9.3 steradian above an irregular southern boundary. The final catalog includes 92,965 sources (in the abstract of Lane et al. (2014) it states 92.964 sources). The VLSSr improves upon the original VLSS in a number of areas including imaging of large sources, image sensitivity, and clean bias; however the most critical improvement is the replacement of an inaccurate primary beam correction which caused source flux errors which vary as a function of radius to the nearest pointing center in the VLSS. This table was initially created by the HEASARC in December 2012, based on the FITS file CATALOG.FIT obtained from the NRAO website at &lt;a href="http://www.cv.nrao.edu/vlss/CATALOG/"&gt;http://www.cv.nrao.edu/vlss/CATALOG/&lt;/a&gt;. It was updated in July 2014 with the the table data from the latest file on the NRAO website (which was marked as last modified on 26 August 2013). Some of the values for the name parameter in the HEASARC&#39;s implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .
17070. VLA M 31 1.4-GHz Source Catalog
ID:
ivo://nasa.heasarc/vlam311p4g
Title:
VLA M 31 1.4-GHz Source Catalog
Short Name:
VLAM311P4G
Date:
18 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
This table contains the Data Release 2 of the Point Source Catalog created from a series of previously constructed radio-continuum images of M 31 at a wavelength lambda of 20 cm (frequency nu = 1.4 GHz) from archived VLA observations. In total, the authors identify a collection of 916 unique discrete radio sources across the field of M 31. Comparing these detected sources with those listed by Gelfand et al. (2004, ApJS, 155, 89, HEASARC table VLAM31325M) at lambda = 92 cm (325 MHz), the spectral index of 98 sources has been derived. The majority (73%) of these sources exhibit a spectral index of alpha &lt; -0.6, indicating that their emission is predominantly non-thermal in nature, which is typical for background objects and Supernova Remnants (SNRs). This table contains the integrated flux densities for 1,131 detections of 916 unique sources detected at 1.4 GHz in 28 VLA observations. Of these 916 unique sources, 109 were detected in at least two separate images. For such sources, the authors list a group identifier, a group count, and an average flux and error. Sources were cross referenced with the Gelfand et al. (2004) catalog of sources detected at 92 cm. For matched sources, the flux density at this wavelength and the derived spectral index between 20 and 92 cm are listed. This table was created by the HEASARC in May 2015 based on &lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/Other/Ser/189.15"&gt;CDS Catalog J/Other/Ser/189.15&lt;/a&gt; file m31radio.dat. This is a service provided by NASA HEASARC .

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