A deep survey of the AKARI north ecliptic pole field
I. WSRT 20 cm radio survey description, observations and data reduction
Department of Physics and Astronomy, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK e-mail: firstname.lastname@example.org
2 Space Science and Technology Department, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX, UK
3 Institute for Space Imaging Science, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada
4 CSIRO Astronomy and Space Science, Australia Telescope National Facility, CSIRO, Marsfield NSW 2122, Australia
5 Institute of Space and Astronautical Science, JAXA, Yoshino-dai 3-1-1, Sagamihara, Kanagawa 229-8510, Japan
6 SRON Netherlands Institute for Space Research, PO Box 800, 9700 AV Groningen, The Netherlands
7 Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands
8 National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588, Japan
9 Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
10 Physics Section, Faculty of Humanities and Social Sciences, Iwate University, Morioka 020-8550, Japan
11 Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA
12 Department of Physics & Astronomy, School of Science and Technology, University of Sussex, Falmer, Brighton BN1 9QH, UK
Accepted: 26 April 2010
Aims. The Westerbork Radio Synthesis Telescope, WSRT, has been used to make a deep radio survey of an ~1.7 degree2 field coinciding with the AKARI north ecliptic pole deep field. The observations, data reduction and source count analysis are presented, along with a description of the overall scientific objectives.
Methods. The survey consisted of 10 pointings, mosaiced with enough overlap to maintain a similar sensitivity across the central region that reached as low as 21 μJy beam-1 at 1.4 GHz.
Results. A catalogue containing 462 sources detected with a resolution of 17.0 × 15.5 is presented. The differential source counts calculated from the WSRT data have been compared with those from the shallow VLA-NEP survey of Kollgaard et al. 1994, and show a pronounced excess for sources fainter than ~1 mJy, consistent with the presence of a population of star forming galaxies at sub-mJy flux levels.
Conclusions. The AKARI north ecliptic pole deep field is the focus of a major observing campaign conducted across the entire spectral region. The combination of these data sets, along with the deep nature of the radio observations will allow unique studies of a large range of topics including the redshift evolution of the luminosity function of radio sources, the clustering environment of radio galaxies, the nature of obscured radio-loud active galactic nuclei, and the radio/far-infrared correlation for distant galaxies. This catalogue provides the basic data set for a future series of paper dealing with source identifications, morphologies, and the associated properties of the identified radio sources.
Key words: galaxies: active / radio continuum: galaxies / surveys / catalogs / cosmology: observations
© ESO, 2010