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1251. Australia Telescope 20-GHz Survey Bright Source Sample
ID:
ivo://nasa.heasarc/at20gbss
Title:
Australia Telescope 20-GHz Survey Bright Source Sample
Short Name:
AT20GBSS
Date:
21 Feb 2025
Publisher:
NASA/GSFC HEASARC
Description:
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 S<sub>20GHz</sub> > 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 <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/384/775">CDS Catalog J/MNRAS/384/775</a> files table2.dat and table3.dat. This is a service provided by NASA HEASARC .
1252. Australia Telescope 20GHz Survey Catalog, AT20G
ID:
ivo://CDS.VizieR/J/MNRAS/402/2403
Title:
Australia Telescope 20GHz Survey Catalog, AT20G
Short Name:
J/MNRAS/402/2403
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Australia Telescope 20GHz Survey (AT20G) is a blind radio survey carried out at 20GHz with the Australia Telescope Compact Array (ATCA) from 2004 to 2008, and covers the whole sky south of declination 0{deg}. The AT20G source catalogue presented here is an order of magnitude larger than any previous catalogue of high-frequency radio sources, and includes 5890 sources above a 20GHz flux-density limit of 40mJy. All AT20G sources have total intensity and polarisation measured at 20GHz, and most sources south of declination -15{deg} also have near-simultaneous flux-density measurements at 5 and 8GHz. A total of 1559 sources were detected in polarised total intensity at one or more of the three frequencies.
1253. Australia Telescope Hubble Deep Field-South 2.5, 5.2 and 8.7-GHz Source Catalog
ID:
ivo://nasa.heasarc/athdfs3frq
Title:
Australia Telescope Hubble Deep Field-South 2.5, 5.2 and 8.7-GHz Source Catalog
Short Name:
ATHDFS3FRQ
Date:
21 Feb 2025
Publisher:
NASA/GSFC HEASARC
Description:
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) = 22<sup>h</sup> 33<sup>m</sup> 25.96<sup>s</sup>, Dec (J2000.0) = -60<sup>o</sup> 38' 09.0" (2.5 GHz), and RA (J2000.0) = 22<sup>h</sup> 32<sup>m</sup> 56.22<sup>s</sup>, Dec (J2000.0) = -60<sup>o</sup> 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 <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/130/1371">CDS Catalog J/AJ/130/1371</a> 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 .
1254. Australia Telescope Hubble Deep Field-South Combined Source Catalog
ID:
ivo://nasa.heasarc/athdfsccat
Title:
Australia Telescope Hubble Deep Field-South Combined Source Catalog
Short Name:
ATHDFSCCAT
Date:
21 Feb 2025
Publisher:
NASA/GSFC HEASARC
Description:
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 combined 4-frequency AT-HDFS Catalog including fluxes and spectral indices for sources detected at 1.4, 2.5, 5.2, and/or 8.7 GHz observations is presented to complement the single-frequency radio 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, and for the 2.5, 5.2, and/or 8.7 GHz observations which were presented in the reference paper (Paper III, Huynh et al., 2007, AJ, 133, 1331, available at the HEASARC as the ATHDFS3FRQ 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 radio observations were carried out by the ATCA over 4 years from 1998 to 2001. The observations at 1.4 and 2.5 GHz consist of single pointings centered on RA (J2000.0) = 22<sup>h</sup> 33<sup>m</sup> 25.96<sup>s</sup>, Dec (J2000.0) = -60<sup>o</sup> 38' 09.0". The observations at 5.2 and 8.7 GHz consist of single pointings centered on RA (J2000.0) = 22<sup>h</sup> 32<sup>m</sup> 56.22<sup>s</sup>, Dec (J2000.0) = -60<sup>o</sup> 33' 02.7". The 5.2 and 8.7 GHz observations are centered on the HST WFPC field, while the 1.4 and 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 1.4 and 2.5 GHz images. This HEASARC table contains the final consolidated catalog of 473 individual sources and gives the flux densities at all frequencies for each individual radio source. It contains the 466 1.4-GHz sources from Paper II together with 5 unmatched 2.5-GHz sources and 2 unmatched 8.7-GHz sources. The procedure that the authors used to construct this catalog is discussed in Section 6 of the reference paper. This table was created by the HEASARC in December 2012 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/130/1371">CDS Catalog J/AJ/130/1371</a> file table9.dat which contains the entire contents of Table 9 from the published paper. This is a service provided by NASA HEASARC .
1255. Australia Telescope Hubble Deep Field-South 1.4-GHz Source Catalog
ID:
ivo://nasa.heasarc/athdfs1p4g
Title:
Australia Telescope Hubble Deep Field-South 1.4-GHz Source Catalog
Short Name:
ATHDFS1P4G
Date:
21 Feb 2025
Publisher:
NASA/GSFC HEASARC
Description:
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) = 22<sup>h</sup> 33<sup>m</sup> 25.96<sup>s</sup>, Dec (J2000.0) = -60<sup>o</sup> 38' 09.0". This table was created by the HEASARC in November 2012 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/130/1371">CDS Catalog J/AJ/130/1371</a> file table1.dat. This is a service provided by NASA HEASARC .
1256. Australia Telescope Hubble Deep Field-South Optical Identifications Catalog
ID:
ivo://nasa.heasarc/athdfsoid
Title:
Australia Telescope Hubble Deep Field-South Optical Identifications Catalog
Short Name:
ATHDFSOID
Date:
21 Feb 2025
Publisher:
NASA/GSFC HEASARC
Description:
The Australia Telescope Hubble Deep Field-South (ATHDF-S) survey of the Hubble Deep Field-South (HDF-S) reaches sensitivities of ~ 10 µJy (µJy) at 1.4, 2.5, 5.2, and 8.7 GHz, making the ATHDF-S one of the deepest surveys ever performed with the Australia Telescope Compact Array (ATCA). This table contains the optical identifications of the ATHDF-S radio sources (the radio data from which are available in summarized form in the HEASARC ATHDFSCCAT table) using data from the literature. The authors find that ~ 66% of the radio sources have optical counterparts to an I magnitude of 23.5 mags. Deep Hubble Space Telescope (HST) imaging of the area identifies a further 12% of the radio sources. In this table, the authors present data from new spectroscopic observations for 98 of the radio sources and supplement these spectroscopic redshifts with photometric ones calculated from five-band optical imaging. The radio observations and data reduction are detailed in Papers I-III of this series: <pre> I = Norris et al., 2005, AJ, 130, 1358; II = Huynh et al., 2005, AJ, 130, 1373, available at the HEASARC as the ATHDFS1P4G table; III = Huynh et al., 2007, AJ, 133, 1331, available at the HEASARC as the ATHDFSCCAT and ATHDFS3FRQ tables. </pre> Palunas et al. (2000, ApJ, 541, 61) observed the HDF-S region using the Big Throughput Camera (BTC) on the Cerro Tololo Inter-American Observatory (CTIO) 4m during 1998 September. Images were taken in the Sloan Digital Sky Survey (SDSS) u, Johnson B and V, and Cousins R and I filters. In addition, the authors obtained spectra of the ATHDF-S radio sources over two service nights in 2001 July and 2003 October using the multi-fiber 2dF instrument of the Anglo-Australian Telescope (AAT). They acquired low-resolution (9 Angstrom) spectra over the wavelength range from 3800 to 8000 Angstroms. This table was created by the HEASARC in December 2012 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/135/2470">CDS Catalog J/AJ/135/2470</a> files table1.dat and table10.dat which contain the entire contents of Tables 1 and 10 from the published paper. This is a service provided by NASA HEASARC .
1257. Australia Telescope Large Area Survey
ID:
ivo://CDS.VizieR/J/MNRAS/426/3334
Title:
Australia Telescope Large Area Survey
Short Name:
J/MNRAS/426/3334
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Australia Telescope Large Area Survey (ATLAS) has surveyed 7 square degrees of sky around the Chandra Deep Field South and the European Large Area ISO Survey-South 1 fields at 1.4GHz. ATLAS aims to reach a uniform sensitivity of 10uJy/beam rms over the entire region with first data release currently reaching ~30uJy/beam rms. Here we present 466 new spectroscopic redshifts for radio sources in ATLAS as part of our optical follow-up programme. 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.
1258. Australia Telescope Local Group Dwarf Spheroidals 2.1-GHz Components Catalog
ID:
ivo://nasa.heasarc/atlgds2p1g
Title:
Australia Telescope Local Group Dwarf Spheroidals 2.1-GHz Components Catalog
Short Name:
ATLGDS2P1G
Date:
21 Feb 2025
Publisher:
NASA/GSFC HEASARC
Description:
Dwarf spheroidal (dSph) galaxies are key objects in near-field cosmology, especially in connection to the study of galaxy formation and evolution at small scales. In addition, dSphs are optimal targets to investigate the nature of dark matter. However, while we begin to have deep optical photometric observations of the stellar population in these objects, little is known so far about their diffuse emission at any observing frequency, and hence on thermal and non-thermal plasma possibly residing within dSphs. In this paper, the authors present deep radio observations of six local dSphs performed with the Australia Telescope Compact Array (ATCA) at 16 cm wavelength (2100 MHz frequency). They mosaicked a region of radius of about 1 degree around three 'classical' dSphs (CDS), Carina, Fornax, and Sculptor, and of about half of degree around three 'ultrafaint' dSphs (UDS), Bootes II, Segue 2, and Hercules. The rms noise level is below 0.05 mJy for all the maps. The restoring beams full width at half-maximum (FWHM) ranged from (4.2 arcseconds by 2.5 arcseconds) to (30.0 arcseconds by 2.1 arcseconds) in the most elongated case. A catalog, including the 1392 sources detected in the six dSph fields, is presented here. In the reference paper, the main properties of the background sources are discussed, with the positions and fluxes of the brightest objects compared with the FIRST, NVSS, and SUMSS observations of the same fields. The observed population of radio emitters in these fields is dominated by synchrotron sources.The authors have computed the associated source number counts at 2 GHz down to fluxes of 0.25 mJy, which prove to be in agreement with AGN count models. The observations presented in this paper were performed during 2011 July. The project was allocated a total of 123 h of ATCA observing time. The spectral setup included the simultaneous observation of a 2-GHz-wide band centered at 2100 MHz with a 1 MHz spectral resolution for continuum observations (recording all four polarization signals). The mapping of the three CDS required a 19 field-mosaic with a total on-source integration time of about 1 hour per field. For Bootes II and Hercules, a 7 field-mosaic with an on-source integration time of about 2 hours per field was chosen, while Segue 2, due to its smaller size,was imaged with a 3 field-mosaic with about 4 hours per field of integration time (with the purpose of maximizing the sensitivity). More precisely, a total of 16.5, 15.0, 17.0, 13.0, 10.9, and 9.6 hours were spent on-source for Carina, Fornax, Sculptor, Bootes II, Hercules, and Segue 2, respectively. The nominal rms sensitivity in each panel for the actual observing time was 36, 38, 35, 25, 28, and 20 µJy for Carina, Fornax, Sculptor, Bootes II, Hercules, and Segue 2, respectively. See Table 1 of the reference paper for the details of the average restoring beam parameters across all mosaic panels for each field of view (FoV). The authors used two automated routines for source extraction and cataloging, which are provided by the SEXTRACTOR package (Bertin & Arnouts 1996, A&AS, 117, 393) and the task SFIND in MIRIAD. In these maps, SFIND and SEXTRACTOR give nearly identical results for astrometry (number of sources and positions), once the threshold parameters in SEXTRACTOR are tuned (the authors found a threshold typically slightly above 5 sigma). The mismatch in positions is random, and about 1 arcsecond on average for all FoVs. This value can be taken as an estimate of the positional accuracy. Photometry on the other hand, gave quite different results for some sources: in the catalog, the authors used the results from SFIND since this was specifically written to analyze radio images, accounting for artifacts and sidelobes. The number of sources in each dSph FoV is reported in Table 2 of the reference paper. Radio sources can be made up of different components. To decide whether nearby sources are separated sources or components of a single source, the authors visually inspected all the fields where either the angular distance, theta, between sources was < 1 arcminute, or the criterion of Magliocchetti et al. (1998, MNRAS, 300, 257: theta < 100 arcseconds x sqrt[S<sub>peak</sub>/10 mJy]), was satisfied. A more detailed study of the 178 possible multiple sources will be reported in a future paper by these authors. This table was created by the HEASARC in June 2015 based on an electronic version of the source components catalog (Table 4 of the reference paper) which was obtained from the MNRAS web site. In Section 4 of the reference paper, the authors state that they "found 1835 entries in the catalog corresponding to a total of 1392 extracted sources with 178 cases being (possibly) multiple component sources". We note that the table downloaded from the MNRAS web site and used as the basis for this current HEASARC table actually contained only 1834 entries, The reason for this small discrepancy is not known. This is a service provided by NASA HEASARC .
1259. Australia Telescope Low-brightness Survey (ATLBS)
ID:
ivo://CDS.VizieR/J/ApJ/762/16
Title:
Australia Telescope Low-brightness Survey (ATLBS)
Short Name:
J/ApJ/762/16
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Australia Telescope Low-brightness Survey (ATLBS) regions have been mosaic imaged at a radio frequency of 1.4GHz with 6" angular resolution and 72{mu}Jy/beam rms noise. The images (centered at RAJ2000=00:35:00, DEJ2000=-67:00:00 and RAJ2000=00:59:17, DEJ2000=-67:00:00) cover 8.42deg^2^ sky area and have no artifacts or imaging errors above the image thermal noise. Multi-resolution radio and optical r-band images (made using the 4m CTIO Blanco telescope) were used to recognize multi-component sources and prepare a source list; the detection threshold was 0.38mJy in a low-resolution radio image made with beam FWHM of 50". Radio source counts in the flux density range 0.4-8.7mJy are estimated, with corrections applied for noise bias, effective area correction, and resolution bias. The resolution bias is mitigated using low-resolution radio images, while effects of source confusion are removed by using high-resolution images for identifying blended sources. Below 1mJy the ATLBS counts are systematically lower than the previous estimates. Showing no evidence for an upturn down to 0.4mJy, they do not require any changes in the radio source population down to the limit of the survey. The work suggests that automated image analysis for counts may be dependent on the ability of the imaging to reproduce connecting emission with low surface brightness and on the ability of the algorithm to recognize sources, which may require that source finding algorithms effectively work with multi-resolution and multi-wavelength data. The work underscores the importance of using source lists --as opposed to component lists-- and correcting for the noise bias in order to precisely estimate counts close to the image noise and determine the upturn at sub-mJy flux density.
1260. Australia Telescope Low-Brightness Survey Source Catalog
ID:
ivo://nasa.heasarc/atlbs1p4gh
Title:
Australia Telescope Low-Brightness Survey Source Catalog
Short Name:
ATLBS1P4GH
Date:
21 Feb 2025
Publisher:
NASA/GSFC HEASARC
Description:
The Australia Telescope Low-brightness Survey (ATLBS) regions have been mosaic imaged at a radio frequency of 1.4 GHz with 6 arcseconds angular resolution and 72 microJansky per beam (µJy/beam) rms noise. The images (centered at RA 00<sup>h</sup> 35<sup>m</sup> 00<sup>s</sup>, Dec -67<sup>o</sup> 00' 00" and RA 00<sup>h</sup> 59<sup>m</sup> 17<sup>s</sup>, Dec -67<sup>o</sup> 00' 00", J2000 epoch) cover 8.42 deg<sup>2</sup> sky area and have no artifacts or imaging errors above the image thermal noise. Multi-resolution radio and optical r-band images (made using the 4 m CTIO Blanco telescope) were used to recognize multi-component sources and prepare a source list of 1366 1.4-GHZ sources; the detection threshold was 0.38 mJy in a low-resolution radio image made with beam FWHM of 50 arcseconds. Radio source counts in the flux density range 0.4-8.7 mJy are estimated, with corrections applied for noise bias, effective area correction, and resolution bias. The resolution bias is mitigated using low-resolution radio images, while effects of source confusion are removed by using high-resolution images for identifying blended sources. Below 1 mJy the ATLBS counts are systematically lower than the previous estimates. Showing no evidence for an upturn down to 0.4 mJy, they do not require any changes in the radio source population down to the limit of the survey. The work suggests that automated image analysis for counts may be dependent on the ability of the imaging to reproduce connecting emission with low surface brightness and on the ability of the algorithm to recognize sources, which may require that source finding algorithms effectively work with multi-resolution and multi-wavelength data. The work underscores the importance of using source lists - as opposed to component lists - and correcting for the noise bias in order to precisely estimate counts close to the image noise and determine the upturn at sub-mJy flux density. This table was created by the HEASARC in April 2013 based on an electronic version of Table 2 from the reference paper that was obtained from the ApJ web site.. This is a service provided by NASA HEASARC .

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