The VLA-COSMOS Survey: I. Radio Identifications from the Pilot Project

We present a catalog of 246 radio sources found in the central 1 degree of the COSMOS field at 1.4GHz. The VLA pilot project data have a resolution of 1.9×1.6 and an rms noise limit of ∼ 25-100μJy/beam covering 0.837 deg. About 20 radio sources are clearly extended and most of them appear to be double-lobed radio galaxies. We find evidence for a cluster of 7 radio sources with an extent of ∼10 southeast of the COSMOS field center. This VLA pilot project was undertaken to demonstrate the feasibility of wide-field mosaicking at 2” resolution at 1.4GHz using the VLA in its A array configuration. The 7-point mosaic data was used to develop the techniques necessary for reduction and analysis. These data will provide the initial astrometric frame for the optical (groundand space-based) data of the COSMOS 2deg survey. In addition, it demonstrates the feasibility of obtaining deep (rms ∼ few μJy) radio imaging of this field at 1.4GHz, since the brightest radio emission peak detected within the area covered has a flux density of 13mJy/beam and no strong side-lobes from sources surrounding the COSMOS field were detected. Comparison of the number counts to other deep radio surveys shows that the COSMOS field is a representative deep field in the radio domain. Subject headings: surveys — radio continuum: galaxies