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1251. 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:
01 Nov 2024
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 .
1252. 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:
01 Nov 2024
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 .
1253. 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:
01 Nov 2024
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 .
1254. 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.
1255. 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:
01 Nov 2024
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 .
1256. 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.
1257. Australia Telescope Low-Brightness Survey Source Catalog
ID:
ivo://nasa.heasarc/atlbs1p4gh
Title:
Australia Telescope Low-Brightness Survey Source Catalog
Short Name:
ATLBS1P4GH
Date:
01 Nov 2024
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 .
1258. Australia Telescope-PMN Catalog of Southern Radio Sources
ID:
ivo://nasa.heasarc/atpmncat
Title:
Australia Telescope-PMN Catalog of Southern Radio Sources
Short Name:
ATPMNCAT
Date:
01 Nov 2024
Publisher:
NASA/GSFC HEASARC
Description:
This table contains a source catalog of 9040 radio sources derived from high-resolution observations of a selection of 8385 Parkes-MIT-NRAO (PMN) sources made with the Australia Telescope Compact Array (ATCA). The catalog lists flux density and structural measurements at 4.8 and 8.6 GHz, derived from observations of all PMN sources in the declination range -87 degrees < Dec < -38.5 degrees (exclusive of galactic latitudes |b| < 2 degrees) with PMN flux density S<sub>4850</sub> > 70mJy (> 50 mJy south of Dec = -73 degrees). The authors assess the quality of the data, which was gathered in the 1992-1994 time period, and the resulting source parameters. They describe the population of catalogued sources, and compare it to samples from complementary catalogs. In particular, they find 122 radio sources with highly probable association with gamma-ray sources observed by the orbiting Fermi Large Area Telescope (LAT), and 11 more radio sources with possible associations with Fermi LAT sources. This Australia Telescope PMN (ATPMN) catalog lists the source measurements of flux density, position and structure of a selection of sources from the PMN catalog. Each catalog entry corresponds to a discrete source observed by the ATCA. In many cases, a single PMN source yields several ATPMN sources. Apart from the name of the parent PMN source, there is no indication of physical association: multiple sources in the one field may be aligned by chance, or may be components of the one object. This catalog contains the following information for each source: position; the flux density at 4.8 and 8.6 GHz; uncertainties in each flux density; the source size modelled as an ellipse (major axes, minor axes, position angle) of the best fit for a Gaussian brightness distribution; the spectral index computed between 4.8 and 8.6 GHz; the uncertainty in the spectral index; a code denoting the epoch of the observation. In the table as given in the original reference, the positions were given with varying degrees of precision, from 0.001 to 1 second of time in RA and from 0.01 to 1 arcsecond in Declination. The authors state in Section 4 of the reference paper that the error in a position coordinate is less than 10 times the final digit given in the coordinate. The positions as displayed in this table do not reflect this system: e.g., a Dec value displayed as '-79 58 34.00' may have been given in the original table as '-79 58 34.00' or '-79 58 34.0' or '-79 58 34'. To recover this information about positional precision the HEASARC has created two additional parameters ra_accuracy and dec_accuracy which list the number of digits after the decimal point given in the original table for the RA and Dec, respectively. Thus, if ra_accuracy = 3, the RA was given to a precision of 0.001 s in the original table, implying that the actual error in RA was less than 10 * 0.001 = 0.01 s. This table was created by the HEASARC in July 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/422/1527">CDS Catalog J/MNRAS/422/1527</a> file atpmncat.dat. This is a service provided by NASA HEASARC .
1259. Australia Telescope PMN follow-up survey
ID:
ivo://CDS.VizieR/J/MNRAS/422/1527
Title:
Australia Telescope PMN follow-up survey
Short Name:
J/MNRAS/422/1527
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a source catalogue derived from high-resolution observations of a selection of PMN sources with the Australia Telescope Compact Array (ATCA). The catalogue lists 8385 sources with flux-density measurements at 4.8 and 8.6GHz, derived from observations of all fields in the declination range -87{deg}<DE<-38.5{deg} (exclusive of galactic latitudes |b|<2{deg{) with PMN flux-density S_4850_>70mJy (50mJy south of DE=-73{deg}). We assess the quality of the data, which was gathered in 1992-1994, and the resulting source parameters. We describe the population of catalogued sources, and compare it to samples from complementary catalogues. In particular we find 126 radio sources with probable association with gamma-ray sources observed by the orbiting Fermi Large Area Telescope.
1260. Autoclassification of the variable 3XMM sources
ID:
ivo://CDS.VizieR/J/ApJ/813/28
Title:
Autoclassification of the variable 3XMM sources
Short Name:
J/ApJ/813/28
Date:
21 Oct 2021
Publisher:
CDS
Description:
In the current era of large surveys and massive data sets, autoclassification of astrophysical sources using intelligent algorithms is becoming increasingly important. In this paper we present the catalog of variable sources in the Third XMM-Newton Serendipitous Source catalog (3XMM) autoclassified using the Random Forest machine learning algorithm (RF). We used a sample of manually classified variable sources from the second data release of the XMM-Newton catalogs (2XMMi-DR2) to train the classifier, obtaining an accuracy of ~92%. We also evaluated the effectiveness of identifying spurious detections using a sample of spurious sources, achieving an accuracy of ~95%. Manual investigation of a random sample of classified sources confirmed these accuracy levels and showed that the Random Forest machine learning algorithm is highly effective at automatically classifying 3XMM sources. Here we present the catalog of classified 3XMM variable sources. We also present three previously unidentified unusual sources that were flagged as outlier sources by the algorithm: a new candidate supergiant fast X-ray transient, a 400s X-ray pulsar, and an eclipsing 5hr binary system coincident with a known Cepheid.

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