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Australia Telescope 2FGL Unassociated Sources Radio Source Catalog
The authors report results of the first phase of observations with the Australia Telescope Compact Array (ATCA) at 5 and 9 GHz of the fields around 411 gamma-ray sources having declinations less than +10 degrees which were detected by the Fermi Gamma-ray Space Telescope, but marked as unassociated in the 2nd Fermi Large-Area Telescope (2FGL) Catalog (available at the HEASARC as the FERMILPSC table). They have detected 424 radio sources with flux densities in the range from 2 mJy to 6 Jy in the fields of 283 gamma-ray sources within their gamma-ray position error ellipses (drawn to cover the area of 99 per cent probability of their localization). Of these, 146 objects were detected in both 5- and 9-GHz bands. The authors found 84 sources with spectral indices flatter than -0.5 in their sample. The majority of detected sources are weaker than 100 mJy and for this reason were not found in previous surveys. Approximately 1/3 of this sample, 128 objects, have the probability of being associated which is more than 10 times the probability of their being a background source found in the vicinity of the gamma-ray object by chance. This table contains the catalog of positions of these radio sources, estimates of their flux densities and their spectral indices, when available. This table was created by the HEASARC in July 2013 based on the electronic versions of Tables 1, 2 and 3 from the reference paper which were obtained from the MNRAS web site. This is a service provided by NASA HEASARC .
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AT20G/Fermi 1FGL Source Catalog
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The high-frequency radio sky, like the gamma-ray sky surveyed by the Fermi satellite, is dominated by flat-spectrum radio quasars and BL Lac objects at bright flux levels. To investigate the relationship between radio and gamma-ray emission in extragalactic sources, the authors have cross-matched the Australia Telescope 20-GHz survey catalog (AT20G: Murphy et al. 2010, MNRAS, 402, 2403, available as a HEASARC Browse table) with the Fermi-LAT 1-year Point Source Catalog (1FGL: Abdo et al. 2010, ApJS, 188, 405, also available as the HEASARC Browse table FERMILPSC). The 6.0 sr of sky covered by both catalogs (Declination < 0 degrees, |b| > 1.5 degrees) contains 5890 AT20G radio sources and 604 1FGL gamma-ray sources. The AT20G source positions are accurate to within ~1 arcsec and, after excluding known Galactic sources, 43% of Fermi 1FGL sources have an AT20G source within the 95% Fermi confidence ellipse. Monte Carlo tests imply that at least 95% of these matches are genuine associations. Only five gamma-ray sources (1% of the Fermi catalog) have more than one AT20G counterpart in the Fermi error box. The AT20G matches also generally support the active galactic nucleus (AGN) associations in the First LAT AGN Catalog. The authors find a trend of increasing gamma-ray flux density with 20 GHz radio flux density. The Fermi detection rate of AT20G sources is close to 100% for the brightest 20 GHz sources, decreasing to 20% at 1 Jy, and to roughly 1% at 100 mJy. Eight of the matched AT20G sources have no association listed in 1FGL and are presented here as potential gamma-ray AGNs for the first time. The authors also identify an alternative AGN counterpart to one 1FGL source. The percentage of Fermi sources with AT20G detections decreases toward the Galactic plane, suggesting that the 1FGL catalog contains at least 50 Galactic gamma-ray sources in the southern hemisphere that are yet to be identified. This table contains the complete list of all 233 Fermi-AT20G matches. This table was created by the HEASARC in August 2010 based on the electronic version of Table 4 obtained from the ApJ web site. This is a service provided by NASA HEASARC .
Fermi 2FGL Unassociated Gamma-Ray Sources Possible Radio Identifications
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This table contains some of the results from an all-sky radio survey between 5- and 9-GHz of sky areas surrounding all unassociated gamma-ray objects listed in the Fermi Large Area Telescope (LAT) Second Source Catalog (2FGL). The goal of these observations is to find all new gamma-ray active galactic nucleus (AGN) associations with radio sources > 10 mJy at 8GHz. The authors observed with the Very Large Array (VLA) and the Australia Telescope Compact Array (ATCA) the areas around unassociated sources, providing localizations of weak radio point sources found in 2FGL fields at arcminute scales. They then followed up a subset of these with the Very Long Baseline Array (VLBA) and the Long Baseline Array (LBA) in order to confirm detections of radio emission on parsec-scales. The authors quantified association probabilities based on known statistics of source counts and assuming a uniform distribution of background sources. In total, they found 865 radio sources at arcsecond scales as candidates for association and detected 95 of 170 selected for follow-up observations at milliarcsecond resolution. Based on this, they obtained firm associations for 76 previously unknown gamma-ray AGNs. Comparison of these new AGN associations with the predictions from using the Wide-field Infrared Survey Explorer (WISE) color-color diagram shows that half of the associations are missed. The authors found that in 129 out of 588 gamma-ray sources observed at arcminute scales not a single radio continuum source was detected above their sensitivity limit within the 3-sigma gamma-ray localization. These "empty" fields were found to be particularly concentrated at low Galactic latitudes. The nature of these Galactic gamma-ray emitters is not yet determined. A list of 216 target fields were observed with the VLA. The instantaneous bandwidth was split into two parts, with one half centered at 5.0 GHz (4.5 - 5.5 GHz) and the other centered at 7.3 GHz (6.8 - 7.8 GHz). The observations were made on 2012 October 26 and 2012 November 3. See section 2.1 of the reference paper for more details. These data are included in this HEASARC table. During the first campaign with the ATCA from 2012 September 19-20, the authors observed 411 2FGL unassociated sources in a Declination range of -90 degrees to +10 degrees at 5.5 and 9 GHz. The details of this observing campaign and results have been reported by Petrov et al. (2013, MNRAS, 432, 1294: available at the HEASARC as the AT2FGLUS table). The authors detected a total of 424 point sources. In a second ATCA campaign on 2013 September 25-28, the authors re-observed sources that were detected at 5 GHz, but were not detected at 9 GHz. See section 2.2 of the reference paper for more details. These data are included in this HEASARC table. Follow-up observations of 149 targets selected from the VLA and ATCA surveys above -30 degrees Declination were conducted with the VLBA between 2013 Feb-Aug (VCS7 project; 4.128 - 4.608 and 7.392 - 7.872 GHz simultaneously) and in 2013 Jun-Dec (campaign S5272; 7.392 - 7.872 GHz only). See section 2.3 of the reference paper for more details. These data are NOT included in this HEASARC table. For sources with Declination below -30 degrees, the authors added 21 objects to the on-going LCS campaign being conducted using the LBA (Petrov et al. 2011, MNRAS, 414, 2528) in 2013 Mar-2013 Jun at 8.200 - 8.520 GHz. See section 2.4 of the reference paper for more details. These data are NOT included in this HEASARC table. This table was created by the HEASARC in May 2015 based on the union of CDS Catalog J/ApJS/217/4/ files table2.dat (the 148 'Category I' objects that were detected at 5.0/5.5 and/or 7.3/9.0 GHz within 2.7' of the 2FGL counterpart localization), table3.dat (the 501 'Category II' objects that were detected at 5.0/5.5 and/or 7.3/9.0 GHz between 2.7' and 6.5' of the 2FGL counterpart localization) and table4.dat (the 216
Australia Telescope Chandra Deep Field-South and SDSS Stripe 82 20-GHz Sources
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This table contains a source catalog, one of the first results from a deep, blind radio survey carried out at 20 GHz with the Australia Telescope Compact Array, with follow-up observations at 5.5, 9 and 18 GHz. The Australia Telescope 20GHz (AT20G) deep pilot survey covers a total area of 5 deg2 in the Chandra Deep Field South and in Stripe 82 of the Sloan Digital Sky Survey. The authors estimate the survey to be 90% complete above 2.5 mJy. Of the 85 sources detected, 55% have steep spectra (spectral index alpha1.420 < -0.5) and 45% have flat or inverted spectra (alpha1.420 >= -0.5). The steep-spectrum sources tend to have single power-law spectra between 1.4 and 18 GHz, while the spectral indices of the flat- or inverted-spectrum sources tend to steepen with frequency. Among the 18 inverted-spectrum (alpha1.420 >= 0.0) sources, 10 have clearly defined peaks in their spectra with alpha1.45.5 > 0.15 and alpha918 < -0.15. On a 3-yr time-scale, at least 10 sources varied by more than 15 percent at 20 GHz, showing that variability is still common at the low flux densities probed by the AT20G-Deep Pilot (AT20GDP) survey. The AT20G-Deep Pilot survey was carried out with he ATCA in 2009 July, shortly after the telescope was provided with a new wide-bandwidth correlator, the CABB. As a result of this upgrade to the telescope, the observing bandwidth was increased by a factor of 16, from 2x128 to 2x2048 MHz, in all bands (ranging from 1.1 to 105 GHz), greatly increasing the sensitivity of continuum observations. These observations were made in continuum mode using two 2048-MHz CABB bands centered at 19 and 21 GHz, with each 2048-MHz band divided into 2048 1-MHz channels. All four Stokes parameters were measured. This table was created by the HEASARC in August 2015 based on the union of CDS Catalog J/MNRAS/439/1212 files table2.dat (the 50 sources in the 3-hr field) and table3.dat (the 35 sources in the 21-hr field). This is a service provided by NASA HEASARC .
Australia Telescope 20-GHz (AT20G) High-Angular Resolution Catalog
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This table contains the high-angular-resolution catalog for the Australia Telescope 20-GHz (AT20G) survey, using the high-angular-resolution 6-km antenna data at the baselines of ~4500 m of the Australia Telescope Compact Array (ATCA). The authors have used the data to produce the visibility catalog that separates the compact active galactic nuclei (AGNs) from the extended radio sources at the 0.15-arcsecond angular scale, corresponding to the linear size scale of 1 kpc at redshifts higher than 0.7. They find the radio population at 20 GHz to be dominated by compact AGNs constituting 77% of the total sources in the AT20G. In the paper, they introduce the visibility-spectra diagnostic plot, produced using the AT20G cross-matches with lower frequency radio surveys at 1 GHz [the NRAO VLA Sky Survey (NVSS: Condon et al. 1998, AJ, 115, 1693) and the Sydney University Molonglo Sky Survey (SUMSS: Mauch et al. 2003, MNRAS, 342, 1117)], that separates the 20-GHz population into distinct sub-populations of the compact AGNs, the compact steep-spectrum (CSS) sources, the extended AGN-powered sources and extended flat-spectrum sources. The extended flat-spectrum sources include a local thermal emitting population of high-latitude planetary nebulae and also gravitational lens and binary black hole candidates among the AGNs. The authors find a smooth transition in properties between the CSS sources and the AGN populations. The visibility catalog, together with the main AT20G survey, provides an estimate of angular size scales for sources in the AT20G and an estimate of the flux arising from central cores of extended radio sources. The identification of the compact AGNs in the AT20G survey provides high-quality calibrators for high-frequency radio telescope arrays and very large baseline interferometry observations. This table was created by the HEASARC in December 2013 based on machine-readable versions of Tables 2 and 3 from the reference paper which were obtained from the MNRAS web site. This is a service provided by NASA HEASARC .
Australia Telescope 20-GHz Survey Bright Source Sample
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The Australia Telescope 20-GHz (AT20G) Survey is a blind survey of the whole southern sky at 20 GHz (with follow-up observations at 4.8 and 8.6 GHz) carried out with the Australia Telescope Compact Array from 2004 to 2007. The Bright Source Sample (BSS) is a complete flux-limited sub-sample of the AT20G Survey catalog comprising 320 extragalactic (|b| > 1.5 degrees) radio sources south of declination -15 degrees with 20-GHz flux densities S20GHz > 0.50 Jy (500 mJy). Of these sources, 218 have near simultaneous observations at 8 and 5 GHz. In the reference paper, the authors present an analysis of the radio spectral properties in total intensity and polarization, size, optical identifications and redshift distribution of the BSS sources. Optical identifications provided an estimation of redshift for 186 sources with median values of 1.20 and 0.13 for QSOs and galaxies, respectively. This table was created by the HEASARC in August 2008 based on the CDS Catalog J/MNRAS/384/775 files table2.dat and table3.dat. This is a service provided by NASA HEASARC .
Australia Telescope Hubble Deep Field-South 2.5, 5.2 and 8.7-GHz Source Catalog
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Deep radio observations of a wide region centered on the Hubble Deep Field-South (HDF-S) have been performed, providing one of the most sensitive sets of radio observations acquired on the Australia Telescope Compact Array (ATCA) to date. A central rms of ~ 10 µJy is reached at four frequencies (1.4, 2.5, 5.2, and 8.7 GHz). In this table, the full source catalogs from the 2.5, 5.2, and 8.7 GHz observations are presented to complement the data for the 1.4 GHz observations which were presented in Paper II (Huynh et al., 2005, AJ, 130, 1373, available at the HEASARC as the ATHDFS1P4G table) in this series, along with a detailed analysis of image quality and noise. The authors also have produced a consolidated catalog of all of their ATCA observations of the HDF-S by matching sources across all four of the frequencies in their survey (available at the HEASARC as the ATHDFSCCAT table). The details of the observations and data reduction are discussed in detail in Paper I of this series (Norris et al., 2005, AJ, 130, 1358) and summarized in Table 1 of the reference paper. The observations consist of single pointings centered on RA (J2000.0) = 22h 33m 25.96s, Dec (J2000.0) = -60o 38' 09.0" (2.5 GHz), and RA (J2000.0) = 22h 32m 56.22s, Dec (J2000.0) = -60o 33' 02.7" (5.2 and 8.7 GHz). The 5.2 and 8.7 GHz observations are centered on the HST WFPC field, while the 2.5 GHz observations were pointed halfway between the WFPC field and a bright confusing source to allow the bright source to be well cleaned from the 2.5 GHz image. At 5 sigma, the 5.2 and 8.7 GHz catalogs have over 96% reliability. At 2.5 GHz, the authors have enough statistics to examine the 5 - 5.5 sigma sources, and find that these are only about 40% reliable. With a SNR greater than 5.5 sigma, the 2.5 GHz catalog would have about 99% reliability. The authors thus cut off the catalogs at 5.5, 5, and 5 sigma for 2.5, 5.2, and 8.7 GHz, respectively. The final catalogs have 71, 24, and 6 sources at 2.5, 5.2, and 8.7 GHz, respectively. Given a prior 1.4 GHz position, it may be feasible to push the detection limit lower than 5 sigma. The authors searched for low-SNR sources by matching 3 - 5 sigma sources that lie within 2 sigma positional uncertainty of a 1.4 GHz source. The positional uncertainty was determined by adding the average 1.4 GHz uncertainty (1.1") in quadrature with the positional uncertainty of a 3 sigma source. At 2.5 GHz the allowed positional offset is 3.8", and for 5.2 and 8.7 GHz it is 2.8". Thus, there are 71, 18, and 2 sources at 2.5, 5.2, and 8.7 GHz, respectively, which are low-SNR high-frequency counterparts to 1.4 GHz sources. The authors included these sources in supplementary catalogs. This HEASARC table contains all 101 primary sources detected at 2.5, 5.2, and 8.7 GHz, as well as the 91 supplementary sources described above (the latter are flagged by having source_flag values of 'S'), for a grand total of 192 radio sources. This table was created by the HEASARC in December 2012 based on the CDS Catalog J/AJ/130/1371 files table47.dat, table58.dat and table68.dat, which contain the entire contents of Tables 4, 5, 6, 7 and 8 from the published paper. This is a service provided by NASA HEASARC .
AT Large Area Survey (ATLAS) CDF-S/SWIRE 1.4-GHz Components Catalog
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This table contains some of the first results from the Australia Telescope Large Area Survey (ATLAS), which consists of deep 1.4-GHz radio observations of a 3.7 deg2 field surrounding the Chandra Deep Field-South (CDF-S), largely coincident with the infrared Spitzer Wide-Area Infrared Extragalactic (SWIRE) Survey. A total of 784 radio components are identified, corresponding to 726 distinct radio sources, nearly all of which are identified with SWIRE sources in the companion table ATLASCSID. Of the radio sources with measured redshifts, most lie in the redshift range 0.5 to 2 and include both star-forming galaxies and active galactic nuclei. The authors identify a rare population of infrared-faint radio sources that are bright at radio wavelengths but are not seen in the available optical, infrared, or X-ray data. Such rare classes of sources can only be discovered in wide, deep surveys such as this. The radio observations where made on 2002 Apr 4-27, Aug 24-29 and 2004 Jan 7-12, Feb 1-5, Jun 6-12 and Nov 24-30, with the Australia Telescope Compact Array (ATCA). The observations in 2002 were made in a mosaic of 7 overlapping fields, for a total of 149 hours of integration time, or 21.3 hours per pointing. The observations in 2004 were taken in the AT mosaic mode, in which the array was cycled around 21 pointing centers They total 173 hours of integration time, or 8.2 hours per pointing. All observations were made with two 128-MHz bands, centered on frequencies of 1344 and 1472 MHz. This table contains the list of 784 radio components given in Table 4 of the reference paper. The authors define a radio 'component' as a region of radio emission identified in the source extraction process. They define a radio 'source' as one or more radio components that appear to be physically connected and that probably correspond to one galaxy. Thus, the authors count a classical triple radio-loud source as being a radio source consisting of three radio components, but count a pair of interacting starburst galaxies as being two sources, each with one radio component. This table was created by the HEASARC in August 2012 based on CDS Catalog J/AJ/132/2409 file table4.dat. This is a service provided by NASA HEASARC .
Australia Telescope Hubble Deep Field-South 1.4-GHz Source Catalog
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This table derives from a paper which is part of a series describing the results from the Australia Telescope Hubble Deep Field-South (ATHDFS) survey obtained with the Australia Telescope Compact Array. This survey consists of observations at 1.4, 2.5, 5.2, and 8.7 GHz, all centered on the Hubble Deep Field-South. Herein are presented the first results from the extended observing campaign at 1.4 GHz. A total of 466 sources have been cataloged to a local sensitivity of 5-sigma (11 µJy rms). A source extraction technique is developed that (1) successfully excludes spurious sources from the final source catalogs and (2) accounts for the nonuniform noise in the image. A source catalog is presented, and the general properties of the 1.4-GHz image are discussed in the reference paper. In the latter, the authors also present source counts derived from their ATHDFS 1.4-GHz catalog. The 1.4 GHz observations were carried out by the Australia Telescope Compact Array over 4 years from 1998 to 2001. They consist of single pointings centered on RA (J2000.0) = 22h 33m 25.96s, Dec (J2000.0) = -60o 38' 09.0". This table was created by the HEASARC in November 2012 based on the CDS Catalog J/AJ/130/1371 file table1.dat. This is a service provided by NASA HEASARC .
ATLargeAreaSurvey(ATLAS)CDF-S&ELAIS-S11.4-GHzDR2ComponentsCatalog
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This table derives from the first of two papers describing the second data release (DR2) of the Australia Telescope Large Area Survey (ATLAS) at 1.4 GHz. This survey comprises deep wide-field observations in total intensity, linear polarization, and circular polarization over the Chandra Deep Field-South (CDF-S) and European Large Area Infrared Space Observatory Survey (ELAIS)-South 1 regions. DR2 improves upon the first data release by maintaining consistent data reductions across the two regions, including polarization analysis, and including differential number counts in total intensity and linear polarization. Typical DR2 sensitivities across the mosaicked multi-pointing images are 30 µJy per beam at approximately 12 arcseconds by 6 arcseconds resolution over a combined area of 6.4 square degrees. In their paper, the authors present detailed descriptions of their data reduction and analysis procedures, including corrections for instrumental effects such as positional variations in image sensitivity, bandwidth smearing with a non-circular beam, and polarization leakage, and application of the BLOBCAT source extractor. They present the DR2 images and catalogs of components (discrete regions of radio emission) and sources (groups of physically associated radio components), and describe new analytic methods to account for resolution bias and Eddington bias when constructing differential number counts of radio components. The authors use the term 'component' to refer to an isolated region of emission that is best described by a single 2D elliptical Gaussian. Blended regions of contiguous emission may consist of multiple individual components. Following the terminology from Hales et al. (2012, MNRAS, 425, 979), a 'blob' is an agglomerated island of pixels above an SNR cutoff, which may encapsulate a single component or a blended region of emission. In Section 6 of the reference paper, the authors use the term 'source' to refer to single or multiple components belonging to the same astronomical object. This HEASARC table contains the ATLAS 1.4 GHz DR2 component catalog, a portion of which is displayed in Table A1 of the reference paper for guidance regarding its form and content. The catalog lists a total of 2,588 components in total intensity and linear polarization; no components were discovered in circular polarization. A list of the ATLAS 1.4 GHz DR2 sources, a portion of which is displayed in Table B1 of the reference paper for guidance regarding its form and content, is not included in this HEASARC table. This table was created by the HEASARC in October 2014 based on an electronic version of Table A1 from the reference paper which was obtained from the MNRAS web site. This is a service provided by NASA HEASARC .
COSMOS Field VLBA Observations 1.4-GHz Source Catalog
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This table contains the results of a project using wide-field Very Long Baseline Interferometry (VLBI) observations at 1.4 GHz of 2,865 known radio sources in the Cosmic Evolution Survey (COSMOS) field, a field which has exceptional multi-wavelength coverage. The main objective of this study is to identify the active galactic nuclei (AGN) in this field. Wide-field VLBI observations were made of all known radio sources in the COSMOS field at 1.4 GHz using the Very Long Baseline Array (VLBA). The authors also collected complementary multiwavelength information from the literature for the VLBA-detected sources.The combination of the number of sources, sensitivity, angular resolution and the area covered by this project are unprecedented. A catalog which contains the VLBI-detected sources is presented, the main purpose of which is to be used as an AGN catalog. the complementary multiwavelength (optical, infrared and X-ray) information of the VLBI-detected sources is also presented. The authors have detected 468 radio sources, expected to be AGN, with the VLBA. This is, to date, the largest sample assembled of VLBI-detected sources in the sub-mJy regime. They find a detection fraction of 20% +/- 1%, considering only those sources from the input catalog which were in principle detectable with the VLBA (2,361). As a function of the VLA flux density, the detection fraction is higher for higher flux densities, since at high flux densities a source could be detected even if the VLBI core accounts for a small percentage of the total flux density. As a function of redshift, the authors see no evolution of the detection fraction over the redshift range 0.5 < z < 3. In addition, they find that faint radio sources typically have a greater fraction of their radio luminosity in a compact core: ~70% of the sub-mJy sources detected with the VLBA have more than half of their total radio luminosity in a VLBI-scale component, whereas this is true for only ~30% of the sources that are brighter than 10 mJy. This suggests that fainter radio sources differ intrinsically from brighter ones. Across the entire sample, the authors find the predominant morphological classification of the host galaxies of the VLBA-detected sources to be early type (57%), although this varies with redshift and at z > 1.5 they find that spiral galaxies become the most prevalent (48%). The number of detections is high enough to study the faint radio population with statistically significant numbers. The authors demonstrate that wide-field VLBI observations, together with new calibration methods such as multi-source self-calibration and mosaicking, result in information which is difficult or impossible to obtain otherwise. This table contains 504 entries, including the 468 VLBA-detected sources and, for sources with multiple components, entries for the individual components. Among the detected sources, there are 452 single, 13 double, 2 triple and 1 quadruple source. Source entries have no suffix in their vlba_source_id, e.g., 'C3293', whereas component entries have a, b, c or d suffixes, e.g., 'C0090a' (and a value of 2 for the multi_cpt_flag parameter). This table was created by the HEASARC in December 2017 based on CDS Catalog J/A+A/607/A132 files vlba_cat.dat and vlba_mw.dat. This is a service provided by NASA HEASARC .
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