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VLA Low-Frequency Sky Survey Redux Source Catalog
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", 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", and an average map rms noise level of sigma ~ 0.1 Jy beam<sup>-1</sup>. 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 <a href="http://www.cv.nrao.edu/vlss/CATALOG/">http://www.cv.nrao.edu/vlss/CATALOG/</a>. 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's implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .
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NRAO VLA Sky Survey Catalog
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This table contains the National Radio Astronomy Observatory (NRAO) Very Large Array (VLA) Sky Survey, the so-called NVSS Catalog. The NVSS Catalog covers the sky north of the J2000.0 Declination of -40 degrees (82% of the celestial sphere) at 1.4 GHz. The principal data products of the NVSS were (1) a set of 2326 4 degree by 4 degree continuum "cubes" with three planes containing Stokes I, Q, and U images, plus (2) a catalog of almost 2 million discrete sources stronger than a flux density S of about 2.5 mJy. The images all have 45 arcsecond FWHM angular resolution and nearly uniform sensitivity. Their rms brightness fluctuations are approximately 0.45 mJy/beam = 0.14 K (Stokes I) and approximately 0.29 mJy/beam = 0.09 K (Stokes Q and U). The rms uncertainties in right ascension and declination vary from <= ~1 arcsecond for the 400,000 sources stronger than 15 mJy to 7 arcseconds at the survey limit. The NVSS was made as a service to the astronomical community. All data products, user software, and updates were released via the World-Wide Web as soon as they were produced and verified. For more complete information on the NVSS, please refer to the NVSS website at http://www.cv.nrao.edu/nvss/ This table was created by the HEASARC in October 2002 based on the file ftp://ftp.cv.nrao.edu/nvss/CATALOG/NVSSCatalog.text.gz provided by the NVSS Catalog's authors. It was updated by the HEASARC in June 2009 to fix a problem with the original ingest in which the leading digit of some flux fields was lost. This is a service provided by NASA HEASARC .
VLA ELAIS N1, N2, N3 Fields 20-cm Source Catalog
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The authors have used the Very Large Array (VLA) in C configuration to carry out a sensitive 20-cm radio survey of regions of the sky that have been surveyed in the far-infrared (FIR) over the wavelength range 5 -200 microns (µm) with ISO (Infrared Space Observatory) as part of the European Large-Area ISO Survey (ELAIS). As usual in surveys based on a relatively small number of overlapping VLA pointings, the flux limit varies over the area surveyed: from a 5-sigma limit of 0.135 mJy over an area of 0.12 deg2 to 1.15 mJy or better over the whole region covered of 4.22 deg2. In their paper, the authors present the complete radio catalog of 867 sources, 428 of which form a complete sample in the flux range 0.2 - 1.0 mJy. These regions of the sky have previously been surveyed to shallower flux limits at 20 cm with the VLA as part of the VLA D-configuration NVSS (full width at half-maximum, FWHM = 45arcseconds) and VLA-B configuration FIRST (FWHM = 5 arcseconds) surveys. This whole survey has a nominal 5-sigma flux limit a factor of 2 below that of the NVSS; 3.4 deg2 of the survey reaches the nominal flux limit of the FIRST survey and 1.5 deg2 reaches 0.25 mJy, a factor of 4 below the nominal FIRST survey limit. In addition, this survey is at a resolution intermediate between the two surveys and thus is well suited for a comparison of the reliability and resolution-dependent surface brightness effects that affect interferometric radio surveys. The authors have carried out a detailed comparison of their survey and these two independent surveys in order to assess the reliability and completeness of each. Considering the whole sample, they found that to the 5-sigma nominal limits of 2.3 and 1.0 mJy, respectively, the NVSS and FIRST surveys have a completeness of 96+2-3 and 89+2-3 % and a reliability of 99+1-2 and 94+2-2 %. The radio observations were obtained of three ISO ELAIS survey regions in the Northern celestial hemisphere (N1 1610+5430, N2 1636+4115 and N3 1429+3306) (see Table 1 of the reference paper for the details of the fields and the individual pointings). The observations are made with the Very Large Array (VLA) radio telescope at 1.4 GHz (20 cm) in the VLA C configuration (maximum baseline 3.4 km) with an angular resolution (FWHM) of ~15 arcseconds. The aim of these VLA observations was to obtain uniform coverage of the ELAIS regions with an rms noise limit of ~50 microJansky (µJy). This table contains the 921 components of 867 total sources detected at a level of >= 5 sigma (44 of which are multiple component sources as defined in Section 4.3 of the reference paper) over a total area of 4.222 deg2. There are also entries describing the properties of the total sources for the 44 multi-component sources (for which the positions have been computed as the flux-weighted average positions of their components), and thus this catalog contains 965 (921 + 44) entries. To filter out the latter, component_id values != 'T' should be selected when searching this table. This table was originally ingested by the HEASARC in August 2012, based on CDS Catalog J/MNRAS/302/222 file table3.dat. It was last updated in September 2013 to remove a duplicate entry for the source ELAISR J142743+331323. This is a service provided by NASA HEASARC .
VLA SDSS Stripe 82 Survey 1.4-GHz Source Catalog
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This table contains results from a high-resolution radio survey of the Sloan Digital Sky Survey (SDSS) Southern Equatorial Stripe, also known as Stripe 82. This 1.4-GHz survey was conducted with the Very Large Array (VLA) 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 arcseconds and achieves a median rms noise of 52 µJy/beam (µJy/beam) over 92 deg2. This is the deepest 1.4-GHz survey to achieve this large of an area, filling a gap in the phase space between small, deep and large, shallow surveys. It also serves as a pilot project for a larger high-resolution survey with the Expanded Very Large Array (EVLA). The authors discuss the technical design of the survey and details of the observations, and outline their method for data reduction, in the reference paper. They present a catalog of 17,969 isolated radio components, for an overall source density of ~195 sources deg-2. The astrometric accuracy of the data is excellent, with an internal check utilizing multiply observed sources yielding an rms scatter of 0.19 arcseconds in both Right Ascension and Declination. A comparison to the SDSS DR7 Quasar Catalog further confirms that the astrometry is well-tied to the optical reference frame, with mean offsets of 0.02" +/- 0.01" in Right Ascension, and 0.01" +/- 0.02" in Declination. A check of their photometry reveals a small, negative CLEAN-like bias on the level of 35 uJy. The authors report on the catalog completeness, finding that 97% of FIRST-detected quasars are recovered in the new Stripe 82 radio catalog, while faint, extended sources are more likely to be resolved out by the resolution bias. In their paper, they conclude with a discussion of the optical counterparts to the catalog sources, including 76 newly detected radio quasars. The full catalog as well as a search page and cutout server are available online at http://third.ucllnl.org/cgi-bin/stripe82cutout. The SDSS Stripe 82 observations were made with the National Radio Astronomy Observatory's (NRAO's) VLA. The data were collected over two VLA cycles, 2007-2008 and 2008-2009. The majority of the observations were taken in the A configuration, but the authors also obtained B-configuration coverage of the area in order to improve the sampling of the Fourier (U-V) plane and to increase sensitivity to the extended structure. Area 1 (delineated in black in Figure 1(a) of the paper) was covered in the A and B configurations in 2007-2008, and Area 2 (delineated in purple in Figure 1(a) of the paper) in the A and B configurations in 2008-2009. Area 1 is made up of 275 pointings, and Area 2 has 374, coming to 649 fields, and 92 deg2 covered in total. This table was created by the HEASARC in August 2013 based on a complete machine-readable version of Table 1 from the reference paper which was kindly provided by the first author. This is a service provided by NASA HEASARC .
VLA 74-MHz Deep High-Resolution Survey Source Catalog
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This table contains some of the results from a 74-MHz survey of a 165 deg2 region located near the North Galactic Pole (NGP). This survey has an unprecedented combination of both spatial resolution (25" FWHM) and sensitivity (1-sigma as low as 24mJy/beam). The authors detect 949 sources at the 5-sigma level in this region, enough to begin exploring the nature of the 74-MHz source population. In their paper, they present differential source counts, spectral index measurements, and the size distribution as determined from counterparts in the high-resolution FIRST 1.4-GHz survey. They find a trend of steeper spectral indices for the brighter sources. Further, there is a clear correlation between spectral index and median source size, with the flat-spectrum sources being much smaller on average. Ultra-steep spectrum objects (power-law index alpha <= -1.2, where S_nu ~ nualpha) are identified. These sources are excellent candidates for high-redshift radio galaxies. The data used to produce this survey come from observations taken on 1998 March 7 intended to map two normal galaxies at 74 MHz (NGC 4565 and NGC 4631). These two pointings were separated by 6.4 degrees, roughly the radius of the primary beam at 74 MHz, allowing them to be ideally combined to produce a single deep image roughly 17 x 10 degrees in size. The combination of VLA A-configuration resolution (25 arcsec), favorable ionospheric conditions, and pointings in directions near the NGP, where the background temperature is low, produced the deepest observation ever obtained below 100 MHz. The same algorithm that was used in the 1.4-GHz NVSS was used to identify and characterize sources in this 74-MHz survey. The source detection algorithm had a threshold such that sources must have both a peak and integrated flux density level of at least 5 times the local rms noise level. Since the rms noise level varied from 24 mJy/beam to 80 mJy mJy/beam at the chosen field edge, the absolute level of the source-detection threshold of 5-sigma likewise varied over the image. This table was created by the HEASARC in August 2010 based on CDS catalog J/ApJS/150/417/ file table2.dat. This is a service provided by NASA HEASARC .
VLA-VIRMOS Deep Field 20-cm Source Catalog
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The authors of this table conducted a deep survey (rms noise ~ 17 microJansky or uJy) with the Very Large Array (VLA) at 1.4 GHz, with a resolution of 6 arcseconds, of a 1 deg2 region included in the VIRMOS VLT Deep Survey that is centered at RA and Dec (J2000.0) of 02 26 00, -04 30 00, hereafter the VLA-VIRMOS Deep Field, or VLA-VDF. In the same field, they already had multiband photometry down to IAB = 25, and spectroscopic observations were to be obtained during the VIRMOS VLT survey. The homogeneous sensitivity over the whole field allowed them to derive a complete sample of 1054 radio sources (5-sigma limit) down to a limit of 0.08 mJy. In their paper, the authors 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 catalog of radio sources. To estimate the effect of the resolution bias on their observations, they have modeled the effective angular-size distribution of the sources in their sample and they have used this distribution to simulate a sample of radio sources. Finally, they present the radio count distribution down to 0.08 mJy derived from the catalog. Their counts are in good agreement with the best fit derived from earlier surveys, and are about 50% higher than the counts in the Hubble Deep Field (HDF). The radio count distribution clearly shows, with extremely good statistics, the change in the slope for the sub-mJy radio sources. 19 of the 1054 radio sources were fitted with multiple components. In such cases, the authors list in the catalog an entry for each of the components, identified with a trailing letter (A, B, C or D) in the source name, and an entry for the whole source, identified with a trailing T in the source name. In these cases the total flux was calculated using the task TVSTAT, which allows the integration of the map values over irregular areas, and the sizes are the largest angular sizes. Thus, this catalog contains 1103 entries on 1054 sources, including 49 entries on individual components of composite sources. This table was created by the HEASARC in February 2012 based on CDS Catalog J/A+A/403/857 file catalog.dat. This is a service provided by NASA HEASARC .
WISE All-Sky Source Catalog
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NASA's Wide-field Infrared Survey Explorer (WISE; Wright et al. 2010) mapped the sky at 3.4, 4.6, 12, and 22 μm (W1, W2, W3, W4) in 2010 with an angular resolution of 6.1", 6.4", 6.5", & 12.0" in the four bands. WISE achieved 5σ point source sensitivities better than 0.08, 0.11, 1 and 6 mJy in unconfused regions on the ecliptic in the four bands. Sensitivity improves toward the ecliptic poles due to denser coverage and lower zodiacal background.The All-Sky Release includes all data taken during the WISE full cryogenic mission phase, 7 January 2010 to 6 August 2010, that were processed with improved calibrations and reduction algorithms. Release data products include an Atlas of 18,240 match-filtered, calibrated and coadded image sets, a Source Catalog containing positional and photometric information for over 563 million objects detected on the WISE images, and an Explanatory Supplement that is a guide to the format, content, characteristics and cautionary notes for the WISE All-Sky Release products.
WISE All-Sky Single Exposure (L1b) Source Table
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NASA's Wide-field Infrared Survey Explorer (WISE; Wright et al. 2010) mapped the sky at 3.4, 4.6, 12, and 22 μm (W1, W2, W3, W4) in 2010 with an angular resolution of 6.1", 6.4", 6.5", & 12.0" in the four bands. WISE achieved 5σ point source sensitivities better than 0.08, 0.11, 1 and 6 mJy in unconfused regions on the ecliptic in the four bands. Sensitivity improves toward the ecliptic poles due to denser coverage and lower zodiacal background.The All-Sky Release includes all data taken during the WISE full cryogenic mission phase, 7 January 2010 to 6 August 2010, that were processed with improved calibrations and reduction algorithms. Release data products include an Atlas of 18,240 match-filtered, calibrated and coadded image sets, a Source Catalog containing positional and photometric information for over 563 million objects detected on the WISE images, and an Explanatory Supplement that is a guide to the format, content, characteristics and cautionary notes for the WISE All-Sky Release products.The WISE All-Sky Data Release Single-exposure Source Working Database contains positions and brightness information, uncertainties, time of observation and assorted quality flags for 9,479,433,101 "sources" detected on the individual WISE 7.7s (W1 and W2) and 8.8s (W3 and W4) Single-exposure images. Because WISE scanned every point on the sky multiple times, the Single-exposure Database contains multiple, independent measurements of objects on the sky.Entries in the Single-exposure Source Table include detections of real astrophysical objects, as well as spurious detections of low SNR noise excursions, transient events such as hot pixels, charged particle strikes and satellite streaks, and image artifacts light from bright sources including the moon. Many of the unreliable detections are flagged in the Single-exposure Table, but they have not been filtered out as they were for the Source Catalog. Therefore, the Table must be used with caution. Users are strongly encouraged to read the Cautionary Notes before using the Table.
VLA M 31 325-MHz Source Catalog
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This table contains some of the results from a 325-MHz radio survey of M 31, conducted with the A configuration of the Very Large Array. The survey covered an area of 7.6 square degrees, and a total of 405 radio sources between <~ 6" and 170" in extent were mapped with a resolution of 6" and a 1-sigma sensitivity of ~ 0.6mJy/beam. For each source, its morphological class, major axis thetaM, minor axis thetam, position angle thetaPA, peak flux I, integrated flux density S, spectral index alpha, and spectral curvature parameter {phi were calculated. A comparison of the flux and radial distribution - both in the plane of the sky and in the plane of M 31 - of these sources with those of the XMM-Newton Large-Scale Structure Survey and the Westerbork Northern Sky Survey revealed that a vast majority of sources detected are background radio galaxies. As a result of this analysis, the authors expect that only a few sources are intrinsic to M 31. This study is based on a 5 hr (4 hr on-source) observation of M 31 conducted on 2000 December 15 with the VLA in A configuration. The procedures used to generate the source list and the source properties (essentially making use of the MIRIAD task SFIND) are discussed in Sections 2.2.2 and 2.3 of the reference paper, respectively. This table was created by the HEASARC in September 2014 based on CDS Catalog J/ApJS/155/89 file table3.dat, the GLG (Gelfand, Lazio, Gaensler) source list. This is a service provided by NASA HEASARC .
WISE All-Sky Single Exposure (L1b) Frame Metadata Table
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NASA's Wide-field Infrared Survey Explorer (WISE; Wright et al. 2010) mapped the sky at 3.4, 4.6, 12, and 22 μm (W1, W2, W3, W4) in 2010 with an angular resolution of 6.1", 6.4", 6.5", & 12.0" in the four bands. WISE achieved 5σ point source sensitivities better than 0.08, 0.11, 1 and 6 mJy in unconfused regions on the ecliptic in the four bands. Sensitivity improves toward the ecliptic poles due to denser coverage and lower zodiacal background.The All-Sky Release includes all data taken during the WISE full cryogenic mission phase, 7 January 2010 to 6 August 2010, that were processed with improved calibrations and reduction algorithms. Release data products include an Atlas of 18,240 match-filtered, calibrated and coadded image sets, a Source Catalog containing positional and photometric information for over 563 million objects detected on the WISE images, and an Explanatory Supplement that is a guide to the format, content, characteristics and cautionary notes for the WISE All-Sky Release products.The WISE All-Sky Data Release Single-exposure Source Working Database contains positions and brightness information, uncertainties, time of observation and assorted quality flags for 9,479,433,101 "sources" detected on the individual WISE 7.7s (W1 and W2) and 8.8s (W3 and W4) Single-exposure images. Because WISE scanned every point on the sky multiple times, the Single-exposure Database contains multiple, independent measurements of objects on the sky.Entries in the Single-exposure Source Table include detections of real astrophysical objects, as well as spurious detections of low SNR noise excursions, transient events such as hot pixels, charged particle strikes and satellite streaks, and image artifacts light from bright sources including the moon. Many of the unreliable detections are flagged in the Single-exposure Table, but they have not been filtered out as they were for the Source Catalog. Therefore, the Table must be used with caution. Users are strongly encouraged to read the Cautionary Notes before using the Table.
VLA FIRST ConeSearch
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All MAST catalog holdings are available via a ConeSearch endpoint. The Very Large Array (VLA) FIRST -- Faint Images of the Radio Sky at Twenty-cm -- is a project designed to produce the radio equivalent of the Palomar Observatory Sky Survey over 10,000 square degrees of the North and South Galactic Caps. Using the NRAO Very Large Array (VLA) and an automated mapping pipeline, we produce images with 1.8" pixels, a typical rms of 0.15 mJy, and a resolution of 5". At the 1 mJy source detection threshold, there are ~90 sources per square degree, ~35% of which have resolved structure on scales from 2-30". 30% of the sources have counterparts in the Sloan Digital Sky Survey. The VLA FIRST catalog at MAST was published December 17, 2014. More information is available at http://sundog.stsci.eduAll available missions are listed at http://archive.stsci.edu/vo/mast_services.html.
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