A deep WSRT 1.4 GHz radio survey of the Spitzer Space Telescope FLSv region^*

¹ Netherlands Foundation for Research in Astronomy, Postbus 2, 7990 AA, Dwingeloo, The Netherlands e-mail: morganti@astron.nl
² Joint Institute for VLBI in Europe, Postbus 2, 7990 AA, Dwingeloo, The Netherlands
³ California Institute of Technology, MS 320-47, Pasadena, CA 91125, USA

Received: 13 February 2004
Accepted: 10 May 2004

Abstract

The First Look Survey (FLS) is the first scientific product to emerge from the Spitzer Space Telescope. A small region of this field (the verification strip) has been imaged very deeply, permitting the detection of cosmologically distant sources. We present Westerbork Synthesis Radio Telescope (WSRT) observations of this region, encompassing a ~1 sq. deg field, centred on the verification strip (J2000 RA = 17:17:00.00, Dec = 59:45:00.000). The radio images reach a noise level of ~8.5 μJy beam^-1 – the deepest WSRT image made to date. We summarise here the first results from the project, and present the final mosaic image, together with a list of detected sources. The effect of source confusion on the position, size and flux density of the faintest sources in the source catalogue are also addressed. The results of a serendipitous search for H I emission in the field are also presented. Using a subset of the data, we clearly detect H I emission associated with four galaxies in the central region of the FLSv. These are identified with nearby, massive galaxies.