The VLA 1.4GHz Survey of the Extended Chandra Deep Field South: Second Data Release

TL;DR

This paper presents an improved second data release of a deep 1.4GHz radio survey of the Extended Chandra Deep Field South, providing a more comprehensive catalog of radio sources with enhanced sensitivity and source characterization.

Contribution

The paper introduces a refined data reduction process and a more extensive catalog of radio sources, doubling the number of sources compared to the first release, with detailed source and morphology analysis.

Findings

Catalog of 883 radio sources with flux densities down to 5 times the local rms noise

Improved sensitivity with a best rms of 6 microJy

Identification of 17 likely multiple-component sources

Abstract

Deep radio observations at 1.4GHz for the Extended Chandra Deep Field South were performed in June through September of 2007 and presented in a first data release (Miller et al. 2008). The survey was made using six separate pointings of the Very Large Array (VLA) with over 40 hours of observation per pointing. In the current paper, we improve on the data reduction to produce a second data release (DR2) mosaic image. This DR2 image covers an area of about a third of a square degree and reaches a best rms sensitivity of 6 uJy and has a typical sensitivity of 7.4 uJy per 2.8" by 1.6" beam. We also present a more comprehensive catalog, including sources down to peak flux densities of five or more times the local rms noise along with information on source sizes and relevant pointing data. We discuss in some detail the consideration of whether sources are resolved under the complication of a radio image created as a mosaic of separate pointings each suffering some degree of bandwidth smearing, and the accurate evaluation of the flux densities of such sources. Finally, the radio morphologies and optical/near-IR counterpart identifications (Bonzini et al. 2012) are used to identify 17 likely multiple-component sources and arrive at a catalog of 883 radio sources, which is roughly double the number of sources contained in the first data release.