- ID:
- ivo://nasa.heasarc/bootesdf
- Title:
- Bootes Deep Field WSRT 1.4-GHz Source Catalog
- Short Name:
- Bootes
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This radio source catalog is the result of deep (16x12 hour) Westerbork Synthesis Radio Telescope (WSRT) observations of the approximately 7 square degree Bootes Deep Field, centered at an RA and Declination (J2000) of 14 hr 32 min 5.75 sec, +34 deg 16 arcmin 47.5 arcsec. The survey consisted of 42 discrete pointings, with enough overlap to ensure a uniform sensitivity across the entire field, and with a limiting sensitivity of 28 microJansky (1 sigma rms). The catalog consists of 3172 distinct sources detected with a significance of 5 sigma or greater, of which 316 are resolved by the 13 x 27 arcsec beam. This database table was created by the HEASARC in December 2001 based on the a data file obtained from the authors' FTP site (no longer available). It was modified slightly in March 2011 (using the CDS data file <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/123/1784/catalog.dat">https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/123/1784/catalog.dat</a>) to make the source names adhere to the naming convention of the Dictionary of Nomenclature of Celestial Objects. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/boof153mhz
- Title:
- Bootes Field GMRT 153-MHz Source Catalog
- Short Name:
- BOOF153MHZ
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors obtained deep, high-resolution radio interferometric observations at 153 MHz to complement the extensively studied NOAO Bootes field. In their paper, they provide a description of the observations, data reduction and source catalog construction. From their single-pointing GMRT observation of ~12 hours, they obtained a high-resolution (26" x 22") image of ~11.3 square degrees, fully covering the Bootes field region and beyond. The image has a central noise level of ~1.0 mJy beam<sup>-1</sup>, which rises to 2.0 - 2.5 mJy beam<sup>-1</sup> at the field edge, placing it amongst the deepest ~150 MHz surveys to date. The catalog of 598 extracted sources is estimated to be ~92% complete for > 10 mJy sources, while the estimated contamination by false detections is < 1%. The low rms positional uncertainty of 1.24" facilitates accurate matching against catalogs at optical, infrared and other wavelengths. Differential source counts were determined down to < ~10 mJy. The authors find no evidence for flattening of the counts towards lower flux densities as observed in deep radio surveys at higher frequencies, suggesting that their catalog is dominated by the classical radio-loud AGN population that explains the counts at higher flux densities. Combination with available deep 1.4 GHz observations yields an accurate determination of spectral indices for 417 sources down to the lowest 153 MHz flux densities, of which 16 have ultra-steep spectra with spectral indices below -1.3. The authors confirm that flattening of the median spectral index towards low flux densities also occurs at this frequency. The detection fraction of the radio sources in the NIR K<sub>s</sub>-band is found to drop with radio spectral index, which is in agreement with the known correlation between spectral index and redshift for brighter radio sources. This table contains the list of 598 153-MHz sources detected in the GMRT observation and their properties at this frequency. There are a number of other tables of objects in the Bootes field made at other frequencies: <pre> HEASARC Table | Title | Reference BOOTESDF | 1.4GHz imaging of the Bootes field | de Vries+ 2002,AJ,123,1784 LALABOOCXO | LALA Bootes field X-ray source catalog | Wang+ 2004,AJ,127,213 --- | Faint radio sources in NOAO Bootes field | Wrobel+ 2005,AJ,130,923 --- | 16um sources in the NOAO Bootes field | Kasliwal+ 2005,ApJ,634,L1 XBOOTES | X-ray survey of the NDWFS Bootes field | Kenter+ 2005,ApJS,161,9 XBOOTESOID | Optical counterparts in the NDWFS Bootes | Brand+ 2006,ApJ,64,140 | field | </pre> This table was created by the HEASARC in December 2011 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/535/A38">CDS Catalog J/A+A/535/A38</a> file table3.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/at20gbspol
- Title:
- Bright Extra-Galactic AT20G Sources Polarizations Catalog
- Short Name:
- AT20GBSPOL
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains polarization data for 180 extragalactic sources extracted from the Australia Telescope 20-GHz (AT20G) survey catalog and observed with the Australia Telescope Compact Array (ATCA) during a dedicated, high sensitivity run (sigma<sub>P</sub> ~ 1 mJy). For the sake of completeness, the authors extracted the polarization information for seven extended sources from the 9-yr Wilkinson Microwave Anisotropy Probe co-added maps at 23 GHz. The full sample of 187 sources constitutes a ~ 99% complete sample of extragalactic sources brighter than S<sub>20GHz</sub> = 500 mJy at the selection epoch with Declination below -30<sup>o</sup>. The sample has a 91.4% detection rate in polarization at ~ 20 GHz (94% if considering the sub-sample of point-like sources). The authors have measurements also at 4.8 and 8.6 GHz within ~1 month of the 20-GHz observations for 172 sources so as to reconstruct the spectral properties of the sample in total intensity and in polarization: 143 of them have a polarization detection at all three frequencies. The authors find that there is no statistically significant evidence of a relationship either between the fraction of polarization and frequency or between the fraction of polarization and the total intensity flux density. This indicates that Faraday depolarization is not very important above 4.8 GHz and that the magnetic field is not substantially more ordered in the regions dominating the emission at higher frequencies (up to 20 GHz). The authors estimate the distribution of the polarization fraction and the polarized flux density source counts at ~20 GHz. The selection of the sample was based on the list of confirmed AT20G sources available at the epoch of these observations (2006 October). The authors selected all objects with flux density S<sub>20GHz</sub> > 500 mJy and Declination below -30<sup>o</sup>, excluding the Galactic plane region (|b| <= 1.5o^) and the Large Magellanic Cloud (LMC) region (inside a circle of 5.5<sup>o</sup> radius centered at RA =05:23:34.7 and Dec=-69:45:22 in J2000.0 coordinates). This resulted in a complete sample of 189 sources. The observations were taken on October 1, 2006 using the most compact hybrid configuration of ATCA, H75, excluding the data from the farthest antenna. The longest baseline of this configuration is 75 m, and its T-shape ensures adequate Fourier coverage for snapshots taken on a relatively small range of hour angles and at high elevation. In a number of cases, indicated by source_flags values of 's', 'f' or 'w', the highest frequency data is not at 18 GHz, but at 20 or 23 GHz. This table was created by the HEASARC in January 2015 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/436/2915">CDS Catalog J/MNRAS/436/2915</a> file table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/cgpsngpcat
- Title:
- Canadian Galactic Plane Survey (CGPS) 1420-MHz Compact Source Catalog
- Short Name:
- CGPSNGPCAT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a catalog of compact sources of radio emission at 1420 MHz in the northern Galactic plane from the Canadian Galactic Plane Survey (CGPS). The catalog contains 72,758 compact sources with an angular size less than 3 arcminutes within the Galactic longitude range 52 < l<sub>II</sub> < 192 degrees down to a 5-sigma detection level of ~1.2 mJy. Linear polarization properties are included for 12,368 sources with signals greater than 4 x sigma<sub>QU</sub> in the CGPS Stokes Q and U images at the position of the total intensity peak. In the reference paper, the authors compare the CGPS flux densities with the catalogued flux densities in the Northern VLA Sky Survey (NVSS) catalog for 10,897 isolated unresolved sources with CGPS flux density greater than 4 mJy in order to search for sources that show variable flux density on timescales of several years. They identify 146 candidate variables that exhibit high fractional variations between the two surveys. In addition, they identify 13 candidate transient sources that have CGPS flux density above 10 mJy but that are not detected in the NVSS. In the CGPS, the Synthesis Telescope at the Dominion Radio Astrophysical Observatory (the DRAO ST) provided arcminute-resolution images of the radio continuum and atomic-hydrogen line emission of the northern Galactic Plane. The CGPS DRAO radio continuum observations provided images of Stokes I, Q, and U in four 7.5-MHz sub-bands spanning 35 MHz, centered on 1420 MHz. The observations were carried out in three phases beginning in 1995 and ending in 2009. The sky coverage of each phase and the observing dates are listed in Table 1 of the reference paper. The Galactic plane was covered with a width in Galactic latitude of 9 degrees, centered at b<sub>II</sub> = 1 degree to accommodate the warp of the Galactic disk. The longitude coverage was constrained by the southern Declination limit of ~20 degrees, the range that could be effectively imaged by a linear east-west synthesis telescope array. The Phase II observations included an extension to higher latitudes (b<sub>II</sub> = 17.5 degrees) over a restricted range of longitude. In this table, we present the CGPS 1420-MHz compact source catalog covering 1,464 square degrees and spanning a range of 140 degrees of Galactic longitude between 52 and 192 degrees. This table was created by the HEASARC in June 2017 based upon a machine-readable version of Table 2 from the reference paper that was obtained from the AJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/cgrabs
- Title:
- Candidate Gamma-Ray Blazar Survey Source Catalog
- Short Name:
- CGRABS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors have constructed a uniform all-sky survey of bright blazars, selected primarily by their flat radio spectra, that is designed to provide a large catalog of likely gamma-ray active galactic nuclei (AGNs). The defined sample, the Candidate Gamma-Ray Blazar Survey (CGRaBS) source catalog, has 1625 targets with radio and X-ray properties similar to those of the EGRET blazars, spread uniformly across the |b| > 10 degrees sky. They also report progress toward optical characterization of the sample; of objects with known red magnitude R < 23, 85% have been classified and 81% have measured redshifts. One goal of this program is to focus attention on the most interesting (e.g., high-redshift, high-luminosity, etc.) sources for intensive multi-wavelength study during the observations by the Large Area Telescope (LAT) on the Gamma-Ray Large-Area Space Telescope (GLAST) satellite observatory. This table was created by the HEASARC in April 2008 based on an electronic version of Table 2 of the reference paper obtained from the electronic ApJS web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/uc7c151mhz
- Title:
- 7C Catalog 151-MHz Survey Final Unified Source Catalog
- Short Name:
- UC7C151MHZ
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a final unified catalog for the 7C survey at 151 MHz with a spatial resolution of 70 x 70cosec(Dec) arcsec<sup>2</sup>. This has been constructed by amalgamating the existing catalogs derived from individual fields imaged at this resolution and eliminating redundancy in regions of mutual overlap. This was a non-trivial procedure because the flux in multiple-component sources may be fitted differently on alternative images, owing, for example, to differences in local noise and beam distortion. The final catalog as published thus produced contains 43683 sources. (Note that the HEASARC removed one duplicate source entry for '7C 083231.6+262635' since it had two entries, which were identical except that in one the beam-fitted flux density S<sub>bf</sub> was 834 mJy/beam, while, in the other entry now removed, S<sub>bf</sub> was 840 mJy/beam). Separate final catalogs have been previously published for the 7C Galactic Plane 7CG survey (available as the HEASARC table GP7C151MHZ), and the lower-resolution survey of the low-declination strip 9<sup>h</sup> < RA < 16<sup>h</sup>, 20<sup>o</sup> < Dec < 35<sup>o</sup> (available as the HEASARC table LD7C151MHZ). The individual catalogs for about 40 of the 96 regions contributing to the total have already been published, together with full details of the methodology, in MNRAS or A&AS: <pre> Reference Region Lacy et al. 1995, MNRAS, 276, 614 92 Visser et al. 1995, A&AS, 110, 419 93 Pooley et al. 1998, MNRAS, 298, 637 94-96 Riley et al. 1999, MNRAS, 306, 31 1-33 </pre> and these data are also available via the MRAO website: <a href="http://www.mrao.cam.ac.uk/surveys/7C/">http://www.mrao.cam.ac.uk/surveys/7C/</a> Individual catalogs for the remaining 58 regions by Riley et al. (regions 34-91) were released electronically via the MRAO website in November 2001. These include a re-analysis of data originally published in rather a different parametrization by McGilchrist et al. 1990, MNRAS, 246, 110. The regions re-analyzed are those numbered 41, 44, 59, 60, 62 and 63 and they supersede McGilchrist's 1990 publication. The RA x Dec coverage, the average rms noise, the flux density of the faintest source listed and the completeness limit for each of the individual regions contributing to the final catalog are given in the table <a href="http://cdsarc.u-strasbg.fr/ftp/cats/J_MNRAS/382/1639/regions.dat">http://cdsarc.u-strasbg.fr/ftp/cats/J_MNRAS/382/1639/regions.dat</a>. For further details of the surveys and data analysis procedures please refer to the published papers referenced above and other references contained therein. This table was created by the HEASARC in October 2010 based on CDS table J/MNRAS/382/1639 files 7c.dat and regions.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rt9cc15ghz
- Title:
- 9C Continued 15-GHz Ryle Telescope Survey of VSA Fields Source Catalog
- Short Name:
- RT9CC15GHZ
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The 9C (9th Cambridge) survey of radio sources with the Ryle Telescope at 15.2 GHz was set up to survey the fields of the cosmic microwave background telescope, the Very Small Array (VSA). In their first paper (Waldram et al. 2003, MNRAS, 342, 915), the authors described three regions of the survey, constituting a total area of 529 deg<sup>2</sup> to a completeness limit of ~ 25 mJy. In this follow-up, they present results from a series of deeper regions, constituting a total area of 115 deg<sup>2</sup> complete to ~ 10 mJy and of 29 deg<sup>2</sup> complete to ~ 5.5 mJy. The authors have investigated the source counts and the distributions of the 1.4 to 15.2 GHz spectral indices for these deeper samples. The whole catalog of 643 sources is contained in the present table. Down to their lower limit of 5.5 mJy, the authors detect no evidence for any change in the differential source count from the earlier fitted count above 25 mJy, n(S) = 51(S/Jy)<sup>-2.15</sup> Jy<sup>-1</sup> sr<sup>-1</sup>. They matched both their new and earlier catalogues with the NRAO VLA Sky Survey (NVSS) catalogue at 1.4 GHz and selected flux-limited samples at both 15 and 1.4 GHz. As they expected, they found that the proportions of sources with flat and rising spectra in the samples selected at 15 GHz are significantly higher than those in the samples selected at 1.4 GHz. In addition, for 15-GHz samples selected in three flux density ranges, they detect a significant shift in the median value of the 1.4 to 15.2 GHz spectral index: the higher the flux densities, the higher the proportions of sources with flat and rising spectra. In the area complete to ~ 10 mJy, the authors find five sources between 10 and 15 mJy at 15 GHz, amounting to 4.3 per cent of sources in this range, with no counterpart in the NVSS catalogue. This implies that, had they relied on the NVSS for locating their sources, they could have missed a significant proportion of them at low flux densities. These results illustrate the problems inherent in using a low-frequency catalog to characterize the source population at a much higher frequency and emphasize the value of a blind 15.2-GHz survey. This table was created in November 2010 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/404/1005">CDS catalog J/MNRAS/404/1005</a> file 9c_cont.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rtv9c15ghz
- Title:
- 9C 15-GHz Ryle Telescope Survey of VSA Fields Source Catalog
- Short Name:
- RTV9C15GHZ
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The fields chosen for the first observations of the cosmic microwave background (CMB) with the Very Small Array (VSA) have been surveyed with the Ryle Telescope at 15 GHz. The authors have covered three regions around RA = 00<sup>h</sup>20<sup>m</sup> and Dec = +30<sup>o</sup>, RA = 09<sup>h</sup>40m and Dec = +32<sup>o</sup> and RA = 15<sup>h</sup>40<sup>m</sup> and Dec = +43<sup>o</sup> (J2000.0), comprising an area of 520 deg<sup>2</sup>. There are 465 sources in this entire area which are above the estimated completeness limit of ~ 25 mJy, although a total of ~ 760 sources were detected, some as faint as 10 mJy. The prime motivation of this study was to define a catalog of the foreground sources that must be monitored by the VSA during its observations at 34 GHz. In particular, it provides a means of identifying GigaHertz peaked spectrum (GPS) sources, which are important for the study of radio source evolution, as well as being a significant foreground for CMB observations over a range of wavelengths. Since this will be a new and quite extensive survey, it was desgignated as '9C' or the Ninth Cambridge survey. For the purpose of this particular component of the 9C survey, the authors designated as a subset, 3 circular areas, VSA1, VSA2 and VSA3, defined by the properties listed in Table 2 of the reference paper and reproduced below: <pre> Field Centre J2000.0 Center B1950.0 Radius Area RA Dec RA Dec (degrees) (sq. degrees) VSA1 00 17 36.5 +30 16 39 00 15 00.0 +30 00 00 5.5 95.0 VSA2 09 40 57.7 +31 46 21 09 38 00.0 +32 00 00 6.0 113.0 VSA3 15 36 42.7 +43 20 11 15 35 00.0 +43 30 00 5.0 78.5 </pre> There are 242 sources which were both above the 25 mJy completeness limit and were in the 286.5 deg<sup>2</sup> contained within these 3 circular fields. These source were listed in 3 tables in the reference paper, Table 4 (VSA1), Table 5 (VSA2) and Table 6 (VSA3). These have been combined into this one HEASARC table, in which the HEASARC added a new parameter vsa_field, which is set to 1 for the VSA1 sources, 2 for the VSA2 sources, and 3 for the VSA3 sources. This table was created in November 2010 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/342/915">CDS catalog J/MNRAS/342/915</a> files table4.dat, table5.dat and table6.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/gp7c151mhz
- Title:
- 7C(G) 151-MHz Northern Galactic Plane Survey Catalog
- Short Name:
- GP7C151MHZ
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Results from a survey of the northern Galactic plane (at Declination >= 30<sup>o</sup> at 151 MHz made with the Cambridge Low Frequency Synthesis Telescope (CLFST) are presented in this table. This survey was designated the 7C(G) - i.e. the Galactic portion of the then-ongoing 7C surveys. The 7C(G) covers the regions 80<sup>o</sup> < l < 104<sup>o</sup> and 126<sup>o</sup> < l < 180<sup>o</sup>, for |b| <= 5.5<sup>o</sup>, and has some coverage to |b| ~ 9<sup>o</sup>, with a resolution of ~70 x70 cosec{delta} arcsec<sup>2</sup> (RA x Dec). The observations, data reduction and calibration of this survey are described in the reference paper, and the catalog of 6262 compact sources, with a completeness limit of ~ 0.25 Jy (250 mJy) over most of the survey region, is presented in this table. The catalog has an rms positional accuracy of better than 10 arcseconds, and the flux densities are tied to the scale of Roger, Bridle & Costain (1973, AJ, 78, 1030) with an accuracy of better than 10 per cent. This table was created by the HEASARC in October 2010 based on CDS table J/MNRAS/294/607 file 7cg.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ld7c151mhz
- Title:
- 7C 151-MHz Low-Declination Survey Catalog
- Short Name:
- LD7C151MHZ
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Cambridge Low Frequency Synthesis Telescope (CLFST) has been used at 151 MHz to survey a region of 1393 square degrees, in the range of RA from 9<sup>h</sup> to 16<sup>h</sup>, and of Dec from 20<sup>o</sup> to 35<sup>o</sup>, with an angular resolution of 108 x 108cosec(Dec) arcsec<sup>2</sup>. The rms noise in the maps is in general ~ 35 - 55 mJy/beam, but varies considerably and exceeds this in some areas. The authors have extracted sources with signal-to-noise ratio > 5.5, a total of 5526 sources, and this table contains the catalog of their positions and flux densities. This table was created by the HEASARC in October 2010 based on CDS table J/MNRAS/282/779 file 7c_low.dat. This is a service provided by NASA HEASARC .
