- ID:
- ivo://nasa.heasarc/atlas5p5gh
- Title:
- AT Large Area Survey (ATLAS) E-CDF-S 5.5-GHz Components Catalog
- Short Name:
- ATLAS5P5GH
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Star-forming galaxies are thought to dominate the sub-mJy radio population, but recent work has shown that low-luminosity active galactic nuclei (AGNs) can still make a significant contribution to the faint radio source population. Spectral indices are an important tool for understanding the emission mechanism of the faint radio sources. The authors have observed the extended Chandra Deep Field South at 5.5 GHz using a mosaic of 42 pointings with the Australia Telescope Compact Array (ATCA). Their image reaches an almost uniform sensitivity of ~ 12 µJy (µJy) rms over 0.25 deg<sup>2</sup> with a restoring beam of 4.9 arcsec x 2.0 arcsec, making the ATLAS 5.5-GHz survey one of the deepest 6-cm surveys to date. This table contains the 5.5 GHz catalog of 142 source components corresponding to the 123 sources in this field: the source counts from this field are discussed in the reference paper. This table was created by the HEASARC in February 2013 based on the electronic version of Table 1 from the reference paper which was obtained from the MNRAS web site. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/atlas2p3gh
- Title:
- ATLargeAreaSurvey(ATLAS)ELAIS-S1&CDF-S2.3-GHzSourceCatalog
- Short Name:
- ATLAS2P3GH
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Australia Telescope Large Area Survey (ATLAS) aims to image a 7 deg<sup>2</sup> region centered on the European Large Area ISO Survey - South 1 (ELAIS-S1) field and the Chandra Deep Field South (CDF-S) at 1.4 GHz with high sensitivity (up to sigma ~ 10 uJy) to study the evolution of star-forming galaxies (SFGs) and Active Galactic Nuclei (AGN) over a wide range of cosmic time. The main goal of the present work is to study the radio spectra of an unprecedentedly large sample of sources (~ 2000 observed, ~ 600 detected in both frequencies). This table contains the results from ancillary radio observations at a frequency of 2.3 GHz which were obtained with the Australia Telescope Compact Array (ATCA). It comprises the catalog of sources with measured 1.4 GHz to 2.3 GHz spectral indices (Table 2 in the reference paper), compiled in the framework of ATLAS. It comprises only such sources which have unambiguous detections at both 1.4 GHz and 2.3 GHz, so no upper or lower limits on the spectral index based on non-detections are included. The 2.3-GHz detection limit is 300 uJy (equivalent to 4.5 sigma in the ELAIS-S1 field and 4.0 sigma in the CDF-S). The authors compute spectral indices between 1.4 GHz and 2.3 GHz using matched-resolution images and investigate various properties of their source sample in their dependence on their spectral indices. The authors find the entire source sample to have a median spectral index of -0.74, in good agreement with both the canonical value of -0.7 for optically thin synchrotron radiation and other spectral index studies conducted by various groups. Regarding the radio spectral index Alpha as indicator for source type, they find only marginal correlations so that flat or inverted spectrum sources are usually powered by AGN and hence conclude that, at least for the faint population, the spectral index is not a strong discriminator. They investigate the z-Alpha relation for their source sample and find no such correlation between spectral index and redshift at all. The authors do find a significant correlation between redshift and radio to near-infrared flux ratio, making this a much stronger tracer of high-z radio sources. They also find no evidence for a dependence of the radio-IR correlation on spectral index. This table was created by the HEASARC in August 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/544/A38">CDS Catalog J/A+A/544/A38</a> file spix_pub.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/atlasescpt
- Title:
- AT Large Area Survey (ATLAS) ELAIS-S1/SWIRE 1.4-GHz Components Catalog
- Short Name:
- ATLASESCPT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains results from the Australia Telescope Large Area Survey (ATLAS), and consists of sensitive (1 sigma < 30 uJy) 1.4-GHz radio observations of a 3.9 deg<sup>2</sup> field centered on the European Large Area ISO Survey S1 (ELAIS-S1) region, largely coincident with infrared observations of the Spitzer Wide-Area Infrared Extragalactic (SWIRE) Survey. In their paper, the authors describe the observations and calibration, source extraction, and cross-matching to infrared sources. A total of 1366 radio components are identified, corresponding to 1276 distinct radio sources, 1183 of which are matched with infrared sources in the companion table ATLASESID. The authors have discovered 31 radio sources with no infrared counterpart at all, adding to the class of Infrared-Faint Radio Sources. The radio observations where made on 27 separate days in 2004 and 2005 with the Australia Telescope Compact Array (ATCA) with a total net integration time of 231 hours. as described in detail in Section 2.1 and Tables 1 and 2 of the reference paper. The observations were made in a mosaic of 20 overlapping pointings, where pointings 1-12 have net integration times of 10.5 hours per pointing and pointings 13-24 have net integration times of 13.5 hours per pointing. All observations were made with two 128-MHz bands, centered on frequencies of 1.34 and 1.43 GHz. After editing, the predicted noise level is 22 uJy in the center of the mosaic. Toward the image edges, the noise level increases due to primary beam attenuation. This table contains the list of 1366 radio components given in Table 4 of the reference paper. The authors define a radio 'component' as a region of radio emission which is best defined as a Gaussian. Close radio doubles are very likely to be best represented by two Gaussians and are therefore deemed to consist of two components. Single or multiple components are called a radio source if they are deemed to belong to the same object. This table was created by the HEASARC in August 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/135/1276">CDS Catalog J/AJ/135/1276</a> file table4.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/atlasesid
- Title:
- AT Large Area Survey (ATLAS) ELAIS-S1/SWIRE ID and Classification Catalog
- Short Name:
- ATLASESID
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains results from the Australia Telescope Large Area Survey (ATLAS), and consists of sensitive (1 sigma < 30 uJy) 1.4-GHz radio observations of a 3.9 deg<sup>2</sup> field centered on the European Large Area ISO Survey S1 (ELAIS-S1) region, largely coincident with infrared observations of the Spitzer Wide-Area Infrared Extragalactic (SWIRE) Survey. In their paper, the authors describe the observations and calibration, source extraction, and cross-matching to infrared sources. A total of 1366 radio components are identified, corresponding to 1276 distinct radio sources, 1183 of which are matched with infrared sources in the present table. The authors have discovered 31 radio sources with no infrared counterpart at all, adding to the class of Infrared-Faint Radio Sources. The radio observations where made on 27 separate days in 2004 and 2005 with the Australia Telescope Compact Array (ATCA) with a total net integration time of 231 hours, as described in detail in Section 2.1 and Tables 1 and 2 of the reference paper. The observations were made in a mosaic of 20 overlapping pointings, where pointings 1-12 have net integration times of 10.5 hours per pointing and pointings 13-24 have net integration times of 13.5 hours per pointing. All observations were made with two 128-MHz bands, centered on frequencies of 1.34 and 1.43 GHz. After editing, the predicted noise level is 22 uJy in the center of the mosaic. Toward the image edges, the noise level increases due to primary beam attenuation. This table contains the list of 1276 radio sources and their cross-identifications at optical and infrared wavelengths which were given in Table 5 of the reference paper. The authors define a radio 'component' as a region of radio emission which is best defined as a Gaussian. Close radio doubles are very likely to be best represented by two Gaussians and are therefore deemed to consist of two components. Single or multiple components are called a radio source if they are deemed to belong to the same object. This table was created by the HEASARC in August 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/135/1276">CDS Catalog J/AJ/135/1276</a> file table5.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/atlasspecz
- Title:
- ATLargeAreaSurvey(ATLAS)SpectroscopicClasses&RedshiftsCatalog
- Short Name:
- ATLASSPECZ
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Australia Telescope Large Area Survey (ATLAS) has surveyed 7 square degrees of sky around the Chandra Deep Field South (CDF-S) and the European Large Area ISO Survey-South 1 (ELAIS-S1) fields at 1.4 GHz. ATLAS aims to reach a uniform sensitivity of 10 µJy (µJy) beam<sup>-1</sup> rms over the entire region with first data release currently reaching ~ 30 uJy beam<sup>-1</sup> rms. Here the authors present 466 new spectroscopic redshifts for radio sources in ATLAS as part of their optical follow-up program. Of the 466 radio sources with new spectroscopic redshifts, 142 have star-forming optical spectra, 282 show evidence for active galactic nuclei (AGN) in their optical spectra, 10 have stellar spectra and 32 have spectra revealing redshifts, but with insufficient features to classify. The authors compare their spectroscopic classifications with two mid-infrared diagnostics and find them to be in broad agreement. ATLAS is a pathfinder for the forthcoming Evolution Map of the Universe (EMU) survey and the data presented in this paper will be used to guide EMU's survey design and early science papers. This paper uses H<sub>0</sub> = 70 km s<sup>-1</sup> Mpc<sup>-1</sup>, Omega<sub>M</sub> = 0.3 and Omega<sub>Lambda</sub> = 0.7, and the web-based calculator of Wright (2006, PASP, 118, 1711) to estimate the distance-dependent physical parameters. This table was created by the HEASARC in March 2013 based on an electronic version of Table 2 from the reference paper which was obtained from the MNRAS web site. 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 .
- ID:
- ivo://nasa.heasarc/atcdfsss82
- Title:
- Australia Telescope Chandra Deep Field-South and SDSS Stripe 82 20-GHz Sources
- Short Name:
- ATCDFSSS82
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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 deg<sup>2</sup> 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 alpha<sub>1.4</sub><sup>20</sup> < -0.5) and 45% have flat or inverted spectra (alpha<sub>1.4</sub><sup>20</sup> >= -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 (alpha<sub>1.4</sub><sup>20</sup> >= 0.0) sources, 10 have clearly defined peaks in their spectra with alpha<sub>1.4</sub><sup>5.5</sup> > 0.15 and alpha<sub>9</sub><sup>18</sup> < -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 <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/439/1212">CDS Catalog J/MNRAS/439/1212</a> 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 .
- ID:
- ivo://nasa.heasarc/atcaadfs20
- Title:
- Australia Telescope Compact Array AKARI Deep Field South 20-cm Source Catalog
- Short Name:
- ATCAADFS20
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The results of a deep radio survey at a wavelength of 20 cm are reported for a region containing the AKARI Deep Field South (ADF-S) near the South Ecliptic Pole (SEP), using the Australia Telescope Compact Array (ATCA). The survey (hereafter referred to as the ATCA-ADFS survey) has 1-sigma detection limits ranging from 18.7 to 50 microJansky per beam (µJy/beam, over an area of ~1.1 deg<sup>2</sup>, and ~2.5 deg<sup>2</sup> to lower sensitivity. The observations, data reduction and source count analysis are presented in the paper, along with a description of the overall scientific objectives, and a catalog containing 530 radio sources detected with a resolution of 6.2 x 4.9 arcseconds (contained herein). The AKARI Deep Field South survey was primarily made in the far-infrared at wavelengths of 65, 90, 140, 160 micron (µm) over a 12 deg<sup>2</sup> area with the AKARI Far-Infrared Surveyor (FIS) instrument, with shallower mid-infrared coverage at 9 and 18 um using the AKARI Infrared Camera (IRC) instrument. In addition to the wide survey, deeper mid-infrared pointed observations, using the IRC, covering ~0.8 deg<sup>2</sup> and reaching 5-sigma sensitivities of 16, 16, 74, 132, 280 and 580 uJy at 3.2, 4.6, 7, 11, 15 and 24 um, respectively, were also carried out. The radio observations were collected over a 13 day period in 2007 July using the ATCA operated at 1.344 and 1.432 GHz. The total integration time for the 2007 observations was 120 hours. The 2007 data were augmented with a further deep observation made in 2008 December over five nights towards a single pointing position at the ADF-S, which lay just off center of the larger ATCA-ADFS field reported here. This added a further 50 h of integration time. The data were processed in exactly the same way as that from the 2007 observing sessions. Note that in the terminology of the authors, a radio component is described as a region of radio emission represented by a Gaussian shaped object in the map. Close radio doubles are represented by two Gaussians and are deemed to consist of two components, which make up a single source. A selection of radio sources with multiple components is shown in Fig. 3 of the reference paper. This table was created by the HEASARC in November 2013 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/427/1830">CDS Catalog J/MNRAS/427/1830</a> file table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/atesp1p4gh
- Title:
- Australia Telescope ESO Slice Project 1.4-GHz Source Catalog
- Short Name:
- ATESP1P4GH
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Australia Telescope ESO Slice Project (ATESP) survey is a radio survey which was accomplished with the Australia Telescope Compact Array (ATCA) at 1.4 GHz over the region covered by the ESO Slice Project (ESP: Vettolani et al. 1997, A&A, 325, 954) galaxy redshift survey. This 26-degree<sup>2</sup> region is centered at Declination -40 degrees, and ranges in RA from 22<sup>h</sup> 30<sup>m</sup> to 01<sup>h</sup> 15<sup>m</sup>. The ATESP survey consisted of 16 radio mosaics with 8 x 14 arcseconds resolution and uniform sensitivity (1 sigma noise level of ~ 79 microJansky) over the whole area of the ESP redshift survey. According to the reference paper, the final 6-sigma ATESP catalog contained 2960 sources down to a detection limit of ~ 0.5 mJy (6 sigma), 1402 of which are sub-mJy sources, and 189 of which are multiple sources (168 doubles, 19 triples and 2 quadruples). This table contains the list of 6-sigma or more sources detected in the ATESP survey. For composite sources with multiple components, the individual components each have entries in this table, and there is also an entry for the entire source. Based on the numbers quoted above, this would imply that there should be (2960 + 2*168 + 3*19 + 4*2) = 3361 entries in this table. The HEASARC notes that there are actually 3370 entries in the CDS version of this table that the present table is based on, 169 of which are doubles, 19 triples and 2 quadruples, implying that this version has 2967 sources, slightly more than the number quoted in the reference paper. This table was created by the HEASARC in November 2012 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VIII/63">CDS Catalog VIII/63</a> file atesp.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/at2fglus
- Title:
- Australia Telescope 2FGL Unassociated Sources Radio Source Catalog
- Short Name:
- AT2FGLUS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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 .
- ID:
- ivo://nasa.heasarc/at20gharc
- Title:
- Australia Telescope 20-GHz (AT20G) High-Angular Resolution Catalog
- Short Name:
- AT20GHARC
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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 .
