- ID:
- ivo://CDS.VizieR/J/A+A/619/A134
- Title:
- ATHOS. Flux ratio based stellar parameterization
- Short Name:
- J/A+A/619/A134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The rapidly increasing number of stellar spectra obtained by existing and future large-scale spectroscopic surveys feeds a demand for fast and efficient tools for the spectroscopic determination of fundamental stellar parameters. Such tools should not only comprise customized solutions for one particular survey or instrument, but, in order to enable cross-survey comparability, they should also be capable of dealing with spectra from a variety of spectrographs, resolutions, and wavelength coverages. To meet these ambitious specifications, we developed ATHOS (A Tool for HOmogenizing Stellar parameters), a fundamentally new analysis tool that adopts easy-to-use, computationally inexpensive analytical relations tying flux ratios (FRs) of designated wavelength regions in optical spectra to the stellar parameters effective temperature (Teff), iron abundance ([Fe/H]), and surface gravity (logg). Our Teff estimator is based on FRs from nine pairs of wavelength ranges around the Balmer lines H{beta} and H{alpha}, while for [Fe/H] and logg we provide 31 and 11 FRs, respectively, which are spread between ~4800{AA} and ~6500{AA}; a region covered by most optical surveys. The analytical relations employing these FRs were trained on N=124 real spectra of a stellar benchmark sample that covers a large parameter space of Teff~=4000 to 6500K (spectral types F to K), [Fe/H]~=-4.5 to 0.3dex, and logg~=1 to 5dex, which at the same time reflects ATHOS' range of applicability. We find accuracies of 97K for Teff, 0.16dex for [Fe/H], and 0.26dex for logg, which are merely bounded by finite uncertainties in the training sample parameters. ATHOS' internal precisions can be better by up to 70%. We tested ATHOS on six independent large surveys spanning a wide range of resolutions (R~=2000 to 52000), amongst which are the Gaia-ESO and the SDSS/SEGUE surveys. The exceptionally low execution time (<30ms per spectrum per CPU core) together with a comparison to the literature parameters showed that ATHOS can successfully achieve its main objectives, in other words fast stellar parametrization with cross-survey validity, high accuracy, and high precision. These are key to homogenize the output from future surveys, such as 4MOST or WEAVE.
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- ID:
- ivo://nasa.heasarc/atlasd2cpt
- Title:
- ATLargeAreaSurvey(ATLAS)CDF-S&ELAIS-S11.4-GHzDR2ComponentsCatalog
- Short Name:
- ATLASD2CPT
- Date:
- 21 Feb 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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 .
- ID:
- ivo://nasa.heasarc/atlascscpt
- Title:
- AT Large Area Survey (ATLAS) CDF-S/SWIRE 1.4-GHz Components Catalog
- Short Name:
- ATLASCSCPT
- Date:
- 21 Feb 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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 deg<sup>2</sup> 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 <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/132/2409">CDS Catalog J/AJ/132/2409</a> file table4.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/atlascsid
- Title:
- AT Large Area Survey (ATLAS) CDF-S/SWIRE ID and Classification Catalog
- Short Name:
- ATLASCSID
- Date:
- 21 Feb 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains some of the first results from the Australia Telescope Large Area Survey (ATLAS), which consists of deep radio observations of a 3.7 deg<sup>2</sup> 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 (see the companion table ATLASCSCPT), corresponding to 726 distinct radio sources, nearly all of which are identified with SWIRE sources. 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 726 radio sources and their cross-identifications at optical and infrared wavelengths which were given in Table 6 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. his table was created by the HEASARC in August 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/132/2409">CDS Catalog J/AJ/132/2409</a> file table6.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/atlas5p5gh
- Title:
- AT Large Area Survey (ATLAS) E-CDF-S 5.5-GHz Components Catalog
- Short Name:
- ATLAS5P5GH
- Date:
- 21 Feb 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 .
- ID:
- ivo://nasa.heasarc/atlas2p3gh
- Title:
- ATLargeAreaSurvey(ATLAS)ELAIS-S1&CDF-S2.3-GHzSourceCatalog
- Short Name:
- ATLAS2P3GH
- Date:
- 21 Feb 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:
- 21 Feb 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:
- 21 Feb 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:
- 21 Feb 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://CDS.VizieR/J/ApJ/867/105
- Title:
- ATLAS all-sky stellar ref. catalog, ATLAS-REFCAT2
- Short Name:
- J/ApJ/867/105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Asteroid Terrestrial-impact Last Alert System (ATLAS) observes most of the sky every night in search of dangerous asteroids. Its data are also used to search for photometric variability, where sensitivity to variability is limited by photometric accuracy. Since each exposure spans 7.6{deg} corner to corner, variations in atmospheric transparency in excess of 0.01mag are common, and 0.01mag photometry cannot be achieved by using a constant flat-field calibration image. We therefore have assembled an all-sky reference catalog of approximately one billion stars to m~19 from a variety of sources to calibrate each exposure's astrometry and photometry. Gaia DR2 is the source of astrometry for this ATLAS Refcat2. The sources of g, r, i, and z photometry include Pan-STARRS DR1, the ATLAS Pathfinder photometry project, ATLAS reflattened APASS data, SkyMapper DR1, APASS DR9, the Tycho-2 catalog, and the Yale Bright Star Catalog. We have attempted to make this catalog at least 99% complete to m<19, including the brightest stars in the sky. We believe that the systematic errors are no larger than 5mmag rms, although errors are as large as 20mmag in small patches near the Galactic plane.
![To the extent possible under law, the publisher has waived all copyright and related or neighboring rights to the catalogue of astrometric microlensing events. For details, see the `Creative Commons CC0 1.0 Public Domain dedication <http://creativecommons.org/publicdomain/zero/1.0/>`_. Of course, you should still give proper credit when using this data as required by good scientific practice. .. image:: /static/img/cc0.png :alt: [CC0]](/registry-search/?f%5BcapabilityType_facet%5D%5B%5D=Simple+Cone+Search&f%5Brights_facet%5D%5B%5D=To+the+extent+possible+under+law%2C+the+publisher+has+waived+all+copyright+and+related+or+neighboring+rights+to+the+catalogue+of+astrometric+++microlensing+events.++For+details%2C+see+the+%60Creative+Commons+CC0+1.0+Public+Domain+dedication+%3Chttp%3A%2F%2Fcreativecommons.org%2Fpublicdomain%2Fzero%2F1.0%2F%3E%60_.++Of+course%2C+you+should+still+give+proper+credit+when+using+this+data+as+required+by+good+scientific+practice.%0A%0A..+image%3A%3A+%2Fstatic%2Fimg%2Fcc0.png%0A+++%3Aalt%3A+%5BCC0%5D%0A%0A){kind=link}