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COSMOS VLA Data                                                 Version 2.0
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The Cosmic Evolution Survey (COSMOS) is an HST Treasury Project to
survey a 2 square degree equatorial field, centered on RA=10:00:28.6
and DEC=+02:12:21.0, using the ACS camera. The project also
incorporates major commitments from other observatories around the
world, including the National Radio Astronomy Observatory's (NRAO)
Very Large Array (VLA) radio telescope.

These VLA data represent the large project in which the 2 square degree
COSMOS field with the position given above as the center of the field was 
surveyed for 275 hours. The observations were performed at 1.4 GHz (20 cm), 
using the VLA in its A- and C-configuration between September 2004 and 
September 2005. The survey has reached a sensitivity of a mean rms of
10.5 (15) uJy/beam over 1 (2) square degrees.

The key characteristics of these data:

	Configuration:		VLA A-array & C-array
	Dates of observations:	September, 2004 - January, 2005   (A-array)
                                August, 2005    - September, 2005 (C-array)
	Observing time:		250 hours (A-array)
                                 25 hours (C-array)
	Frequency:		1.4 GHz ( = L band, 20cm)
	Bandwidth:		75 MHz (Multi-channel continuum mode)
	Pointings:		23 (hexagonal pattern)
	Area:			2 sq degs (box used for source extraction)
	Resolution:		1.5" x 1.4"; beam PA -10 degrees
	Sensitivity:		9.5-35 uJy/beam (inner to outermost regions)

A revised version of the source catalog has been released (v2.0):
 (1- v2.0) a source catalog, containing 2,417 sources, with their
           position, fluxes, and sizes
           all sources below 5sigma have been removed
           a correction to the fluxes for bandwidth smearing has
           been applied where necessary (see details in Bondi et al. 2008)

The correction for bandwidth smearing as well as numbers for
completeness correction are described in the paper:

"The VLA-COSMOS Survey: III. Further Catalog Analysis and the Radio 
Source Counts"
by Bondi et al., 2008, ApJ, 681, 1129


The data products available here include:

	(1) a source catalog, containing 3,643 sources, with
	    their position, fluxes, and sizes
	(2) a component catalog of the 80 sources which were fitted with
	    multiple components, with the components'
	    fluxes, and sizes
	(3) a flux calibrated, astrometrically correct image,
	    in SIN projection [ "_sin.fits" file in 
	    http://irsa.ipac.caltech.edu/data/COSMOS_INT/images/vla ]
	(4) a flux calibrated, astrometrically correct image,
	    in TAN projection [ "_tan.fits" file  in 
	    http://irsa.ipac.caltech.edu/data/COSMOS_INT/images/vla ]

The full history of the FITS files (stripped from the headers due to 
their size) may be viewed as text files under the vla/images directory:

  vla_20cm_lg_tan_10_HIST.hdr
  vla_20cm_lg_sin_10_HIST.hdr

Further information may be obtained from the VLA-COSMOS web page:

	http://www.mpia-hd.mpg.de/COSMOS

or the main COSMOS web page:

	http://cosmos.astro.caltech.edu/

The data reduction, image reconstruction and catalog construction is described
in the paper:

"The VLA-COSMOS Survey: II. Source Catalog of the Large Project"
by Schinnerer et al. 2007, ApJS, COSMOS special issue, 172, 46
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