The VIRMOS deep imaging survey^*

III. ESO/WFI deep U-band imaging of the 0226-04 deep field

¹ INAF, Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy
² INAF, Osservatorio Astronomico di Pino Torinese, via Osservatorio 20, 10025 Torino, Italy
³ Università degli Studi di Bologna, Dipartimento di Astronomia, via Ranzani 1, 40127 Bologna, Italy
⁴ INAF, Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy
⁵ Institut d'Astrophysique de Paris, 98bis Bd. Arago, 75014 Paris, France
⁶ Observatoire de Paris, LERMA, 61 avenue de l'Observatoire, 75014 Paris, France
⁷ Istituto di Radioastronomia del CNR, via Gobetti 101, 40129 Bologna, Italy
⁸ Laboratoire d'Astrophysique de Marseille, Traverse du Siphon, 13376 Marseille Cedex 12, France
⁹ Istituto di Astrofisica Spaziale e Fisica Cosmica del CNR, via Bassini 15, 20133 Milano, Italy
¹⁰ INAF, Osservatorio Astronomico di Roma, via Osservatorio 2, 00040 Monteporzio Catone (Roma), Italy

Corresponding author: M. Radovich, radovich@na.astro.it

Received: 6 October 2003
Accepted: 5 December 2003

Abstract

In this paper we describe the U-band imaging of the F02 deep field, one of the fields in the VIRMOS Deep Imaging Survey. The observations were done at the ESO/MPG 2.2 m telescope at La Silla (Chile) using the 8k 8k Wide-Field Imager (WFI). The field is centered at α(J2000^h26^m00^s and δ(J200030´00´´, the total covered area is 0.9  and the limiting magnitude (50% completeness) is  mag. Reduction steps, including astrometry, photometry and catalogue extraction, are first discussed. The achieved astrometric accuracy (rms) is ~ with reference to the I-band catalog and ~ internally (estimated from overlapping sources in different exposures). The photometric accuracy including uncertainties from photometric calibration, is <0.1 mag. Various tests are then performed as a quality assessment of the data. They include: (i) the color distribution of stars and galaxies in the field, done together with the BVRI data available from the VIMOS survey; (ii) the comparison with previous published results of U-band magnitude-number counts of galaxies.