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ATLASESCPT - AT Large Area Survey (ATLAS) ELAIS-S1/SWIRE 1.4-GHz Components Catalog

HEASARC
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Overview

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 deg2 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.


Catalog Bibcode

2008AJ....135.1276M

References

Deep Australia Telescope Large Area Survey radio observations of the european
large area ISO survey S1/Spitzer wide-area infrared  extragalactic field.
    Middelberg E., Norris R.P., Cornwell T.J., Voronkov M.A., Siana B.D.,
    Boyle B.J., Ciliegi P., Jackson C.A., Huynh M.T., Berta S., Rubele S.,
    Lonsdale C.J., Ivison R.J., Smail I.
   <Astron. J., 135, 1276-1290 (2008)>
   =2008AJ....135.1276M

Provenance

This table was created by the HEASARC in August 2012 based on CDS Catalog J/AJ/135/1276 file table4.dat.

Parameters

Name
The designation for the radio component as recommended by the Dictionary of Nomenclature of Celestial Objects, viz., 'ATELAIS JHHMMSS.ss-DDMMSS.s', where the prefix stands for Australia Telescope European Large Area ISO Survey, and the numerical string is the J2000.0 equatorial coordinates of the component. In the case of single-component sources, this is identical to the source name used in Table 5 of the reference paper (the HEASARC ATLASESID table). This is the formal IAU designation and should be used in the literature when referring to this component.

Alt_Name
An alternative designation for the radio component as recommended by the Dictionary of Nomenclature of Celestial Objects, viz., '[MNC2008] CNNNN.N', where the prefix stands for Middelberg, Norris, Cornwell 2008, and the 'CNNNN(.N)' part refers to the component NNNN(.N), an internal designation used in the paper. In some cases, sources were split up into sub-components, resulting in component numbers such as 'C0005' and 'C0005.1'. However, this is no anticipation of the grouping of components into sources, which was carried out independently.

RA
The Right Ascension of the component in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.001 seconds of time in the original table.

Dec
The Declination of the component in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.01 arcseconds in the original table.

LII
The Galactic Longitude of the component.

BII
The Galactic Latitude of the compinent.

RA_Error
The uncertainty in the Right Ascension, in arcseconds. This includes the formal uncertainty derived from the Gaussian fit together with a potential systematic error in the position of the calibrator source of 0.1 arcseconds added in quadrature.

Dec_Error
The uncertainty in the Declination, in arcseconds. This includes the formal uncertainty derived from the Gaussian fit together with a potential systematic error in the position of the calibrator source of 0.1 arcseconds added in quadrature.

Flux_1p4_GHz
The peak flux density of the fitted Gaussian component at 20 cm, in mJy/beam.

Flux_1p4_GHz_Error
The uncertainty in the peak flux density of the fitted Gaussian component at 20 cm, in mJy/beam. This was estimated using Equation (21) in Condon (1997, PASP, 109, 166).

Int_Flux_1p4_GHz
The integrated flux density of the fitted Gaussian component at 20 cm, in mJy.

Int_Flux_1p4_GHz_Error
The associated error in the integrated 20-cm flux density, in mJy. The authors estimated the error of the integrated flux densities using Equation (1) in Schinnerer et al. (2004, AJ, 128, 1974), which is based on Condon (1997, PASP, 109, 166), assuming a relative error of the flux calibration of 5% (whereas Schinnerer et al. (2004) assumed 1%). In the case of extended sources, where the integrated flux density was measured by integrating over a polygon in the image, the authors assumed a 5% scaling error and added to that in quadrature an empirical error arising from the shape and size of the area which it was integrated:

      Delta(S) = sqrt [(0.05S)2 + (10-7/S)2]
  
where S is the flux density in Jy. For extended sources with flux densities of 10 mJy, 1 mJy, and 0.5 mJy, the total errors are thus 0.5 mJy (5%), 0.11 mJy (11%), and 0.2 mJy (40%), respectively, which describe the errors that were found empirically reasonably well.

RMS_1p4_GHz
The value, in mJy/beam (converted by the HEASARC from the units of microJy/beam used in the original table), of the rms map generated by SExtractor at the position of the component.

Major_Axis
The FWHM of the major axis of the Gaussian fit component, in arcseconds.

Minor_Axis
The FWHM of the minor axis of the Gaussian fit component, in arcseconds.

Position_Angle
The major-axis position angle of the Gaussian fit component (measured Eastwards from North), in degrees.

Decon_Flux_1p4_GHz
The deconvolved peak flux density of the component, in mJy/beam. If the deconvolution failed, or the deconvolution yielded a point source, the component was deemed to be unresolved and no value is given.

Decon_Major_Axis
The deconvolved FWHM of the major axis of the Gaussian fit component, in arcseconds. If the deconvolution failed, or the deconvolution yielded a point source, the component was deemed to be unresolved and no value is given.

Decon_Minor_Axis
The deconvolved FWHM of the minor axis of the Gaussian fit component, in arcseconds. If the deconvolution failed, or the deconvolution yielded a point source, the component was deemed to be unresolved and no value is given.

Decon_Position_Angle
The deconvolved major-axis position angle of the Gaussian fit component (measured Eastwards from North), in degrees. If the deconvolution failed, or the deconvolution yielded a point source, the component was deemed to be unresolved and no value is given.

Sidelobe_Flag
This flag parameter is set to 'Y' if the component was deemed by the authors to be a sidelobe rather than a 'real' source. There are 15 such cases (out of 1366 components in this table).


Contact Person

Questions regarding the ATLASESCPT database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 24-Aug-2012