The VIRMOS deep imaging survey^*

II: CFH12K BVRI optical data for the 0226-04 deep field

¹ University of Bologna, Department of Astronomy, via Ranzani 1, 40127 Bologna, Italy
² Laboratoire d'Astrophysique de Marseille, Traverse du Siphon, 13376 Marseille Cedex 12, France
³ Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy
⁴ Institut d'Astrophysique de Paris, 98bis boulevard Arago, 75014 Paris, France
⁵ Osservatorio di Capodimonte, via Moiariello 16, 80131 Napoli, Italy
⁶ Observatoire de Paris, LERMA, 61 avenue de l'Observatoire, 75014 Paris, France
⁷ Canada-France-Hawaii Telescope, 65-1238 Mamalahoa Highway, Kamuela, HI 96743

Corresponding author: H. J. McCracken, hjmcc@bo.astro.it

Received: 24 February 2003
Accepted: 17 June 2003

Abstract

In this paper we describe in detail the reduction, preparation and reliability of the photometric catalogues which comprise the CFH12K-VIRMOS deep field. This region, consisting of four contiguous pointings of the CFH12K wide-field mosaic camera, covers a total area of . The survey reaches a limiting magnitude of , , and (corresponding to the point at which our recovery rate for simulated point-like sources sources falls below ). In total the survey contains 90 729 extended sources in the magnitude range . We demonstrate our catalogues are free from systematic biases and are complete and reliable down these limits. By comparing our galaxy number counts to previous wide-field CCD surveys, we estimate that the upper limit on bin-to-bin systematic photometric errors for the  limited sample is in this magnitude range. We estimate that of the catalogues sources have absolute per co-ordinate astrometric uncertainties less than and . Our internal (filter-to-filter) per co-ordinate astrometric uncertainties are and . We quantify the completeness of our survey in the joint space defined by object total magnitude and peak surface brightness. We also demonstrate that no significant positional incompleteness effects are present in our catalogues to . Finally, we present numerous comparisons between our catalogues and published literature data: galaxy and star counts, galaxy and stellar colours, and the clustering of both point-like and extended populations. In all cases our measurements are in excellent agreement with literature data to . This combination of depth and areal coverage makes this multi-colour catalogue a solid foundation to select galaxies for follow-up spectroscopy with VIMOS on the ESO-VLT and a unique database to study the formation and evolution of the faint galaxy population to and beyond.