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VLSS - VLA Low-Frequency Sky Survey Discrete Source Catalog

HEASARC
Archive

Overview

The VLA Low-Frequency Sky Survey (VLSS) is a 74 MHz (4m) continuum survey covering the entire sky north of -30 degrees declination. Using the VLA in B- and BnA-configurations, the authors will map the entire survey region at a resolution of 80" and with an average rms noise of 0.1 Jy/beam. For a detailed description of the survey and its scientific motivations, please see the original proposal to the skeptical NRAO review committee at http://lwa.nrl.navy.mil/VLSS/proposal.ps or the published reference for the survey (listed below).

The VLSS is being made as a service to the astronomical community, and the principal data products are being released to the public as soon as they are produced and verified. Details and access to the images can be found at http://lwa.nrl.navy.mil/VLSS/

This table contains the 26 June 2007 version of the VLSS catalog of discrete sources obtained from the set of 14 by 14-degree, 74-MHz continuum images in the Stokes I parameter. This catalog was created by fitting elliptical Gaussians to all sources detected at the 5-sigma level or higher. It is based on fields representing roughly 95% of the planned survey area which were available in the second major VLSS data release.

The images are available at http://lwa.nrl.navy.mil/VLSS/. The particular field in which a given source was detected is available as a remote data product to this table.


Catalog Bibcode

2007AJ....134.1245C

References

The VLA Low-frequency Sky Survey
     Perley R.A., Condon J.J., Cotton W.D., Cohen A.S., Lane W.M., Kassim N.E.,
     Lazio T.J.W., Erickson W.C.
    <Proposal from National Radio Astronomy Observatory,
     National Research Council, Naval Research Laboratory,
     University of Maryland (Version May 2006)>
The VLA Low-frequency Sky Survey
     Cohen A.S., Lane W.M., Cotton W.D., Kassim N.E., Lazio T.J.W.,
     Perley R.A., Condon J.J., Erickson W.C.
    <Astron. J., 134, 1245-1262 (2007)>
    =2007AJ....134.1245C

Provenance

This table was updated by the HEASARC in February 2008, based on CDS table VIII/79A file catalog.dat, replacing the first (Aug 2006) version.

HEASARC Implementation

The HEASARC converted the flux densities from Jy to mJy.

Parameters

Name
The designation for the VLSS source as recommended by the authors of the catalog, using the 'VLSS' prefix and the J2000.0 coordinates truncated to 0.1 minutes of time in RA and 1 arcminute in Declination.

RA
The Right Ascension of the VLSS source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.01 arcseconds in the originating table.

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

LII
The Galactic Longitude of the VLSS source.

BII
The Galactic Latitude of the VLSS source.

RA_Error
The mean error in the Right Ascension of the source, in seconds.

Dec_Error
The mean error in the Declination of the source, in arcseconds.

Flux_74_MHz
The integrated flux density of the VLSS source at 74MHz, in mJy.

Flux_74_MHz_Error
The mean error in the integrated flux density of the VLSS source at 74MHz, in mJy.

Major_Axis_Limit
This parameter is set to '<' if the corresponding major axis is an upper limit rather than a measured value.

Major_Axis
The deconvolved major axis of the source, in arcseconds.

Major_Axis_Error
The mean error in the deconvolved major axis of the source, in arcseconds.

Minor_Axis_Limit
This parameter is set to '<' if the corresponding minor axis is an upper limit rather than a measured value.

Minor_Axis
The deconvolved minor axis of the source, in arcseconds.

Minor_Axis_Error
The mean error in the deconvolved minor axis of the source, in arcseconds

Position_Angle
The position angle of the source if extended, i.e., the orientation of its major axis, in degrees, from north through east.

Position_Angle_Error
The mean error in the position angle, in degrees.

Field_Name
The name of the original survey field in which the source was found.

X_Pixel
The X-axis (RA) pixel number of the source in the original survey image field (specified by the field_name parameter) in which the source was present.

Y_Pixel
The Y-axis (Dec) pixel number of the source in the original survey image field (specified by the field_name parameter) in which the source was present.


Contact Person

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

Page Author: Browse Software Development Team
Last Modified: 13-Dec-2012