The VLA-COSMOS 3 GHz Large Project: Continuum data and source catalog release^⋆

¹ Department of Physics, University of Zagreb, Bijenička cesta 32, 10002 Zagreb, Croatia
e-mail: vs@phy.hr
² Istituto di Radioastronomia di Bologna – INAF, via P. Gobetti, 101, 40129 Bologna, Italy
³ INAF–Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy
⁴ California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125, USA
⁵ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
⁶ Argelander Institut for Astronomy, Auf dem Hügel 71, 53121 Bonn, Germany
⁷ National Radio Astronomy Observatory, PO Box 0, Socorro, NM 87801, USA
⁸ CSIRO Australia Telescope National Facility, PO Box 76, Epping, NSW 1710, Australia
⁹ Research School of Astronomy and Astrophysics, Australian National University, Weston Creek, ACT 2611, Australia
¹⁰ Spitzer Science Center, 314-6 Caltech, Pasadena, CA 91125, USA
¹¹ Smithsonian Astrophysical Observatory, 60 Garden St., Cambridge, MA 02138, USA
¹² Astronomisches Institut, Ruhr-Universität Bochum, Universitätsstr. 150, 44801 Bochum, Germany
¹³ Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot, Israel
¹⁴ Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille), UMR 7326, 13388 Marseille, France
¹⁵ Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV, Groningen, The Netherlands
¹⁶ ASTRON – The Netherlands Institute for Radio Astronomy, PO Box 2, 7990 AA, Dwingeloo, The Netherlands
¹⁷ Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
¹⁸ Subdepartment of Astrophysics, University of Oxford, Denys-Wilkinson Building, Keble Road, Oxford OX1 3RH, UK
¹⁹ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
²⁰ Sorbonne Université, UPMC Univ. Paris 06, and CNRS, UMR 7095, IAP, 98bis Bd Arago, 75014 Paris, France
²¹ National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA
²² Astronomy Centre, Department of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH, UK

Received: 13 April 2016
Accepted: 20 June 2016

Abstract

We present the VLA-COSMOS 3 GHz Large Project based on 384 h of observations with the Karl G. Jansky Very Large Array (VLA) at 3 GHz (10 cm) toward the two square degree Cosmic Evolution Survey (COSMOS) field. The final mosaic reaches a median rms of 2.3 μJy beam^-1 over the two square degrees at an angular resolution of 0.75″. To fully account for the spectral shape and resolution variations across the broad (2 GHz) band, we image all data with a multiscale, multifrequency synthesis algorithm. We present a catalog of 10 830 radio sources down to 5σ, out of which 67 are combined from multiple components.Comparing the positions of our 3 GHz sources with those from the Very Long Baseline Array (VLBA)-COSMOS survey, we estimate that the astrometry is accurate to 0.01″ at the bright end (signal-to-noise ratio, S/N_{3 GHz} > 20). Survival analysis on our data combined with the VLA-COSMOS 1.4 GHz Joint Project catalog yields an expected median radio spectral index of α = −0.7. We compute completeness corrections via Monte Carlo simulations to derive the corrected 3 GHz source counts. Our counts are in agreement with previously derived 3 GHz counts based on single-pointing (0.087 square degrees) VLA data. In summary, the VLA-COSMOS 3 GHz Large Project simultaneously provides the largest and deepest radio continuum survey at high (0.75″) angular resolution to date, bridging the gap between last-generation and next-generation surveys.