VLA Goulds Belt Survey Perseus Region Source Catalog
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This table contains a source catalog from multi-epoch, large-scale (~2,000 arcmin
2), fairly deep (~16 microJansky or uJy), high-resolution (~1") radio observations of the Perseus star-forming complex that were obtained with the Karl G. Jansky Very Large Array (VLA) at frequencies of 4.5 and 7.5 GHz. These observations were mainly focused on the clouds NGC 1333 and IC 348, although the authors also observed several fields in other parts of the Perseus complex. They detect a total of 206 sources, 42 of which are associated with young stellar objects (YSOs). The radio properties of about 60% of the YSOs are compatible with a non-thermal radio emission origin. Based on their sample, the authors find a fairly clear relation between the prevalence of non-thermal radio emission and the evolutionary status of the YSOs. By comparing their results with previously reported X-ray observations, they show that YSOs in Perseus follow a Gudel-Benz relation with a value of the kappa parameter (L
X/L
rad = kappa x 10
(15.5 +/- 1) [Hz]) of 0.03, consistent with other regions of star formation. The authors argue that most of the sources detected in their observations that are not associated with known YSOs are extragalactic, but provide a list in the reference paper Of 20 unidentified radio sources whose radio properties are consistent with them being YSO candidates. Finally, they also detect five sources with extended emission features that can clearly be associated with radio galaxies. The observations were collected with the VLA of the National Radio Astronomy Observatory in B and BnA configurations. 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 observing sessions, on 2011 March 06/13, April 14/25, and May 01/02/10/19/22, typically separated from one another by a month. This dual-frequency, multi-epoch strategy was chosen to enable the characterization of the spectral index and variability of the detected sources, as well as to help with the identification of the emission mechanisms. The locations of the VLA observations are shown in Figure 1 of the reference paper. Other details of the observations are given in Table 1 of the reference paper. The approximate positions of the two main fields observed are:
RA (ICRS) DE Designation(s)
03 28 55 +31 22.2 Ced 16 = NGC 1333 03 44 34 +32 09.8 NAME omi Per Cloud = IC 348
This HEASARC table contains the contents of Table 2 (74 radio sources detected in NGC 1333), Table 3 (91 radio sources detected in IC 348) and Table 4 (41 radio sources detected in single fields in Perseus) from the reference paper, totaling 206 radio sources. This table was created by the HEASARC in February 2018 based on an ASCII version of Table 2 from the reference paper that was obtained from the ApJ website and on the CDS catalog J/ApJ/818/116 files table3.dat and table4.dat that contains Tables 3 and 4 from the reference paper. This is a service provided by NASA HEASARC .
VLA Goulds Belt Survey Orion Complex Source Catalog
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This table contains results from a high-sensitivity (60 µJy), large-scale (2.26 deg2) survey obtained with the Karl G. Jansky Very Large Array (JVLA) as part of the Gould's Belt Survey (GBS) program. The authors detected 374 and 354 sources at 4.5 and 7.5 GHz, respectively. Of these, 148 are associated with previously known young stellar objects (YSOs). Another 86 sources previously unclassified at either optical or infrared wavelengths exhibit radio properties that are consistent with those of young stars. The overall properties of these sources at radio wavelengths such as their variability and radio to X-ray luminosity relation are consistent with previous results from the GBS. These detections provide target lists for follow-up Very Long Baseline Array radio observations to determine their distances, as YSOs are located in regions of high nebulosity and extinction, making it difficult to measure their optical parallaxes. The observations were obtained with the JVLA of the National Radio Astronomy Observatory (NRAO) in its A configuration. The observations of the 210 fields in the Orion Molecular Clouds A and B were obtained in three different epochs (2011 June 25 to July 4, July 23 to 30, and August 25 to 29, as described in Table 1 of the reference paper) typically separated from one another by a month. The 210 individual fields have been split into 7 maps, with 30 fields being observed per map, as follows: 12 in the lambda Ori region, 3 in L1622, 27 are shared between NGC 2068 and NGC 2071, 14 are shared between NGC 2023 and NGC 2024, 11 in the sigma Ori region, 109 in the Orion Nebula Cluster (ONC), 16 in L1641-N, 8 in L1641-C, and 10 in L1641-S (see Figures 1 to 7 in the reference paper). Two frequency sub-bands, each 1-GHz wide, and centered at 4.5 and 7.5 GHz, respectively, were recorded simultaneously. The authors achieved a nearly uniform rms noise of 60 µJy beam-1 at both frequencies in all the regions. The only exception to this is in the Trapezium region due to nebular emission; there the noise was 200 µJy beam-1 after excluding baselines smaller than 150 kilo-lambda during imaging to remove extended emission. Sources were identified through a visual inspection of the individual fields at 4.5 GHz during the cleaning and imaging process since an automated source identification was deemed to be not sufficiently advanced and produced results that were too unreliable. In particularly clustered regions such as the Trapezium and NGC 2024, in addition to standard imaging, data from all three epochs were combined into a single image for source identification purposes only to improve statistical significance of each detection. The authors detected a combined total of 374 sources among the three epochs for all of the regions. All sources but one had fluxes greater than five times the rms noise in at least one epoch. The remaining source, 'GBS-VLA J053518.67-052033.1', was detected at two epochs with maximum detection probability of 4.9 sigma in a single epoch data. It is found in the Trapezium region, and has known counterparts in other wavelength regimes. The authors cross-referenced their catalog of sources with previous major radio, infrared, optical and X-ray surveys of the regions published in the literature. They have generally considered sources in these surveys to be counterparts if they had positional coincidences less than 1 arcsecond, but have allowed for larger offsets if the combined uncertainty between the databases was large. Of 374 detected sources, 261 have been previously found at another wavelength region, while 113 are new detections. 146 sources have been detected in X-rays, 94 at optical wavelengths, 218 at infrared, and 63 in previous radio surveys. Of the previously identified sources, 1 is extragalactic, while the other 148 as young stellar objects (YSOs). Of the YSOs, 106 have been placed on the standard class system based on the IRAC color-color classification of
VLA Goulds Belt Survey Serpens Region Source Catalog
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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 .
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 deg
2 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 ~ nu
alpha) 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-COSMOS Project 1.4-GHz Joint Source Catalog
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In the context of the VLA-COSMOS Deep project, additional VLA A array observations at 1.4 GHz were obtained for the central degree of the COSMOS field and combined with the existing data from the VLA-COSMOS Large project. A newly constructed Deep mosaic with a resolution of 2.5 arcseconds was used to search for sources down to 4 sigma with 1 sigma ~ 12 µJy beam-1 in the central 50' x 50'. This new catalog is combined with the catalog from the Large project (obtained at 1.5" x 1.4" resolution) to construct a new Joint catalog. All sources listed in the new Joint catalog have peak flux densities of >= 5 sigma at 1.5" and/or 2.5" resolution to account for the fact that a significant fraction of sources at these low flux levels are expected to be slightly resolved at 1.5" resolution. All properties listed in the Joint catalog, such as peak flux density, integrated flux density, and source size, are determined in the 2.5" resolution Deep image. In addition, the Joint catalog contains 43 newly identified multi-component sources. This table was created by the HEASARC in June 2010 based on the electronic version of Table 3 from the reference paper which was obtained from the ApJ web site. This is a service provided by NASA HEASARC .
VLA-COSMOS Survey 324-MHz Continuum Source Catalog
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This table contains a source catalog based on 90-cm (324-MHz) Very Large Array (VLA) imaging of the COSMOS field, comprising a circular area of 3.14 square degrees centered on 10h 00m 28.6s, _02o 12' 21" (J2000.0 RA and Dec). The image from the merger of 3 nights of observations using all 27 VLA antennas had an effective total integration time of ~ 12 hours, an 8.0 arcsecond x 6.0 arcsecond angular resolution, and an average rms of 0.5 mJy beam-1. The extracted catalog contains 182 sources (down to 5.5 sigma), 30 of which are multi-component sources. Using Monte Carlo artificial source simulations, the authors derive the completeness of the catalog, and show that their 90-cm source counts agree very well with those from previous studies. In their paper, the authors use X-ray, NUV-NIR and radio COSMOS data to investigate the population mix of this 90-cm radio sample, and find that the sample is dominated by active galactic nuclei. The average 90-20 cm spectral index (S_nu_~ nualpha, where Snu is the flux density at frequency nu and alpha the spectral index) of the 90-cm selected sources is -0.70, with an interquartile range from -0.90 to -0.53. Only a few ultra-steep-spectrum sources are present in this sample, consistent with results in the literature for similar fields. These data do not show clear steepening of the spectral index with redshift. Nevertheless, this sample suggests that sources with spectral indices steeper than -1 all lie at z >~ 1, in agreement with the idea that ultra-steep-spectrum radio sources may trace intermediate-redshift galaxies (z >~ 1). Using both the signal and rms maps (see Figs. 1 and 2 in the reference paper) as input data, the authors ran the AIPS task SAD to obtain a catalog of candidate components above a given local signal-to-noise ratio (S/N) threshold. The task SAD was run four times with search S/N levels of 10, 8, 6 and 5, using the resulting residual image each time. They recovered all the radio components with a local S/N > 5.00. Subsequently, all the selected components were visually inspected, in order to check their reliability, especially for the components near strong side-lobes. After a careful analysis, a S/N threshold of 5.50 was adopted as the best compromise between a deep and a reliable catalog. The procedure yielded a total of 246 components with a local S/N > 5.50. More than one component, identified in the 90-cm map sometimes belongs to a single radio source (e.g. large radio galaxies consist of multiple components). Using the 90-cm COSMOS radio map, the authors combined the various components into single sources based on visual inspection. The final catalog (contained in this HEASARC table) lists 182 radio sources, 30 of which have been classified as multiple, i.e. they are better described by more than a single component. Moreover, in order to ensure a more precise classification, all sources identified as multi-component sources have been also double-checked using the 20-cm radio map. The authors found that all the 26 multiple 90-cm radio sources within the 20-cm map have 20-cm counterpart sources already classified as multiple. The authors have made use of the VLA-COSMOS Large and Deep Projects over 2 square degrees, reaching down to an rms of ~15 µJy beam1 ^ at 1.4 GHz and 1.5 arcsec resolution (Schinnerer et al. 2007, ApJS, 172, 46: the VLACOSMOS table in the HEASARC database). The 90-cm COSMOS radio catalog has, however, been extracted from a larger region of 3.14 square degrees (see Fig. 1 and Section 3.1 of the reference paper). This implies that a certain number of 90-cm sources (48) lie outside the area of the 20-cm COSMOS map used to select the radio catalog. Thus, to identify the 20-cm counterparts of the 90-cm radio sources, the authors used the joint VLA-COSMOS catalog (Schinnerer et al. 2010, ApJS, 188, 384: the VLACOSMJSC table in the HEASARC database) for the 134
VLA Goulds Belt Survey Taurus-Auriga Complex Source Catalog
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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
M 17 Chandra X-Ray Point Source Catalog
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This table contains some of the results from a Chandra ACIS observation of the stellar populations in and around the M17 H II region. The field reveals 886 sources (listed in the present table) with observed X-ray luminosities (uncorrected for absorption) between ~ 29.3 erg s-1 < log LX < 32.8 erg s-1, 771 of which have stellar counterparts in infrared images. Spectral analysis results for the 598 brightest X-ray sources which have photometric significance of 2.0 or greater) are also given herein. For 546 of the X-ray sources, the fits used the "wabs(apec)" thermal plasma model in XSPEC assuming scaled 0.3 times solar photospheric abundances, while for the other 52 X-ray sources for which either the thermal model poorly described the data or required nonphysical parameters and the X-ray source was not identified with a known stellar counterpart, the fits used the "wabs(powerlaw)" model in XSPEC. In addition to the comprehensive tabulation of X-ray source properties, several other results were presented in the reference paper: 1. The X-ray luminosity function is calibrated to that of the Orion Nebula Cluster population to infer a total population of roughly 8000-10,000 stars in M17, one-third lying in the central NGC 6618 cluster. 2. About 40% of the ACIS sources are heavily obscured with AV > 10 mag. Some are concentrated around well-studied star-forming regions -- IRS 5/UC1, the Kleinmann-Wright Object, and M17-North -- but most are distributed across the field. As previously shown, star formation appears to be widely distributed in the molecular clouds. X-ray emission is detected from 64 of the hundreds of Class I protostar candidates that can be identified by near- and mid-infrared colors. These constitute the most likely protostar candidates known in M17. 3. The spatial distribution of X-ray stars is complex: in addition to the central NGC 6618 cluster and well-known embedded groups, we find a new embedded cluster (designated M17-X), a 2 pc long arc of young stars along the southwest edge of the M17 H II region, and 0.1 pc substructure within various populations. These structures may indicate that the populations are dynamically young. 4. All (14/14) of the known O stars but only about half (19/34) of the known B0-B3 stars in the M17 field are detected. These stars exhibit the long-reported correlation between X-ray and bolometric luminosities of LX ~ 10-7 Lbol. While many O and early-B stars show the soft X-ray emission expected from microshocks in their winds or moderately hard emission that could be caused by magnetically channeled wind shocks, six of these stars exhibit very hard thermal plasma components (kT > 4 keV) that may be due to colliding wind binaries. More than 100 candidate new OB stars are found, including 28 X-ray detected intermediate- and high-mass protostar candidates with infrared excesses. 5. Only a small fraction (perhaps 10%) of X-ray selected high- and intermediate-mass stars exhibit K-band-emitting protoplanetary disks, providing further evidence that inner disks evolve very rapidly around more massive stars. This table was created by the HEASARC in December 2007 based on electronic versions of Tables 1, 2, 3, 4 and 5 of the reference paper which were obtained from the electronic ApJ web site. This is a service provided by NASA HEASARC .
VLA-COSMOS 3-GHz Large Project Source Catalog
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This table contains some of the results from the VLA-COSMOS 3-GHz Large Project based on 384 hours of observations with the Karl G. Jansky Very Large Array (VLA) at 3 GHz (10 cm) toward the 2 square degree Cosmic Evolution Survey (COSMOS) field. The final mosaic reaches a median rms of 2.3 µJy (µJy) beam
-1 over the 2 square degrees at an angular resolution of 0.75 arcseconds. To fully account for the spectral shape and resolution variations across the broad (2-GHz) band, the authors imaged all the data with a multiscale, multifrequency synthesis algorithm. In this table, the catalog of 10,830 radio sources down to 5 sigma is presented, out of which 67 are combined from multiple components. Comparing the positions of these 3-GHz sources with those from the Very Long Baseline Array (VLBA)-COSMOS survey, the authors estimate that the astrometry is accurate to 0.01 arcseconds at the bright end (signal-to-noise ratio, S/N
3GHz > 20). Survival analysis on these data combined with the VLA-COSMOS 1.4-GHz Joint Project catalog yields an expected median radio spectral index alpha = -0.7. The authors compute completeness corrections via Monte Carlo simulations to derive the corrected 3-GHz source counts. Their counts are in agreement with previously derived 3-GHz counts based on single-pointing (0.087 square degrees) VLA data. In summary, the VLA-COSMOS 3-GHz Large Project simultaneously provides the largest and deepest radio continuum survey at high (0.75") angular resolution to date, bridging the gap between last-generation and next-generation surveys. The catalog contains sources selected down to a 5-sigma (where sigma ~2.3 µJy/beam) threshold. This catalog can be used for statistical analyses, accompanied with the corrections given in the data & catalog release paper. All completeness and bias corrections and source counts presented in the paper were calculated using this sample. The total fraction of spurious sources in the COSMOS 2 sq.deg. field is below 2.7% within this catalog. However, an increase of spurious sources up to 24% at 5.0 < S/N < 5.5 is present (for details see Sec. 5.2., Fig. 17 and Table 3 of the reference paper). A subsample with a minimal spurious source fraction can be selected by requiring an additional cutoff S/N >= 5.5 for single component sources (MULTI=0). The total fraction of spurious sources in the COSMOS 2 sq.deg. field within such a selected sample is below 0.4%, and the fraction of spurious sources is below 3% even at the lowest S/N of 5.5. This table was created by the HEASARC in June 2017 based on
CDS Catalog J/A+A/602/A1 file table1.dat, the VLA-COSMOS 3-GHz radio source catalog. This is a service provided by NASA HEASARC .