English

VLA 1.4GHz observations of the GOODS-North Field: Data Reduction and Analysis

Cosmology and Nongalactic Astrophysics 2015-05-18 v1

Abstract

We describe deep, new, wide-field radio continuum observations of the Great Observatories Origins Deep Survey -- North (GOODS-N) field. The resulting map has a synthesized beamsize of ~1.7" and an r.m.s. noise level of ~3.9uJy/bm near its center and ~8uJy/bm at 15', from phase center. We have cataloged 1,230 discrete radio emitters, within a 40' x 40' region, above a 5-sigma detection threshold of ~20uJy at the field center. New techniques, pioneered by Owen & Morrison (2008), have enabled us to achieve a dynamic range of 6800:1 in a field that has significantly strong confusing sources. We compare the 1.4-GHz (20-cm) source counts with those from other published radio surveys. Our differential counts are nearly Euclidean below 100uJy with a median source diameter of ~1.2". This adds to the evidence presented by Owen & Morrison (2008) that the natural confusion limit may lie near ~1uJy. If the Euclidean slope of the counts continues down to the natural confusion limit as an extrapolation of our log N - log S, this indicates that the cutoff must be fairly sharp below 1uJy else the cosmic microwave background temperature would increase above 2.7K at 1.4 GHz.

Keywords

Cite

@article{arxiv.1004.1671,
  title  = {VLA 1.4GHz observations of the GOODS-North Field: Data Reduction and Analysis},
  author = {Glenn E. Morrison and Frazer N. Owen and Mark Dickinson and Rob J. Ivison and Edo Ibar},
  journal= {arXiv preprint arXiv:1004.1671},
  year   = {2015}
}

Comments

Accepted for publication in ApJS. 16 pages, 19 figures. Radio data and source list can be found at http://www.ifa.hawaii.edu/~morrison/GOODSN/