ATATS - Allen Telescope Array Twenty-cm Survey (ATATS) Source Catalog

Overview

This table contains the source catalog from the Allen Telescope Array Twenty-centimeter Survey (ATATS), a multi-epoch (12 visits), 690 deg² radio image and catalog at 1.4 GHz. The survey is designed to detect rare, very bright transients as well as to verify the capabilities of the ATA to form large mosaics. The combined image using data from all 12 ATATS epochs has an rms noise sigma = 3.94 mJy beam^-1 and a dynamic range of 180, with a circular beam of 150 arcseconds FWHM. It contains 4408 sources to a limiting sensitivity of 5 sigma = 20 mJy beam^-1. The authors compare the catalog generated from this 12-epoch combined image to the NRAO VLA Sky Survey (NVSS), a legacy survey at the same frequency, and find that they can measure source positions to better than ~ 20 arcseconds. For sources above the ATATS completeness limit, the median flux density is 97% of the median value for matched NVSS sources, indicative of an accurate overall flux calibration. The authors examine the effects of source confusion due to the effects of differing resolution between the ATATS and NVSS on their ability to compare flux densities. They detect no transients at flux densities greater than 40 mJy in comparison with NVSS and place a 2 sigma upper limit of 0.004 deg^-2 on the transient rate for such sources. These results suggest that the >~ 1 Jy transients reported by Matsumara et al. (2009, AJ, 138, 787) may not be true transients, but rather variable sources at their flux density threshold.

Catalog Bibcode

2010ApJ...719...45C

References

The Allen Telescope Array Twenty-centimeter Survey - A 690 Square Degree, 12
Epoch Radio Data Set. I. Catalog and Long-duration Transient Statistics
   Croft, S. et al.
  <Astrophys. J. 719, 45 (2010)>
  =2010ApJ...719...45C

Provenance

This table was created by the HEASARC in September 2010 based on the electronic version of Table 2 from the reference paper which was obtained from the ApJ web site.

Parameters

Name
The radio source designation, using the 'ATATS' prefix (for Allen Telescope Array Twenty-cm Survey) and the J2000.0 equatorial source coordinates truncated to 1 second of time in RA and 1 arcsecond in Dec, as recommended by the Dictionary Of Nomenclature of Celestial Objects.

RA
The Right Ascension of the radio source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.1 seconds of time in the original table.

Dec
The Declination of the radio source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.1 arcseconds in the original table.

LII
The Galactic Longitude of the radio source.

BII
The Galactic Latitude of the radio source.

Flux_20_cm
The flux density of the radio source at 1.4 GHz as measured in the ATATS, in mJy.

Flux_20_cm_Error
The rms of the local background in the ATATS map, in mJy.

Major_Axis
The major axis of the restoring beam, in arcseconds.

Minor_Axis
The minor axis of the restoring beam, in arcseconds.

Position_Angle
The position angle of the major axis of the restoring beam.

Num_Near_NVSS_Srcs
The number of NVSS source matches within 75 arcseconds of the ATATS source position.

NVSS_Flux_20_cm
The sum of the integrated flux densities of the NVSS sources within 75 arcseconds of the ATATS source position.

Contact Person

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

Page Author: Browse Software Development Team
Last Modified: Tuesday, 21-Sep-2010 14:47:03 EDT