EDP Sciences
Free access
Volume 410, Number 1, October IV 2003
Page(s) 17 - 32
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20031081

A&A 410, 17-32 (2003)
DOI: 10.1051/0004-6361:20031081

The VIRMOS deep imaging survey

II: CFH12K BVRI optical data for the 0226-04 deep field
H. J. McCracken1, 2, 3, M. Radovich4, 5, E. Bertin4, 6, Y. Mellier4, 6, M. Dantel-Fort6, O. Le Fèvre2, J. C. Cuillandre7, S. Gwyn2, S. Foucaud2 and G. Zamorani3

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

(Received 24 February 2003 / Accepted 17 June 2003)

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 $1.2\deg^2$. The survey reaches a limiting magnitude of $B_{\rm AB}\sim 26.5$, $V_{\rm AB}\sim26.2$, $R_{\rm AB}\sim25.9$ and $I_{\rm AB}\sim25.0$ (corresponding to the point at which our recovery rate for simulated point-like sources sources falls below  $50\%$). In total the survey contains 90 729 extended sources in the magnitude range $18.0<I_{\rm AB}<24.0$. 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 I- limited sample is ${\sim} 10\%$ in this magnitude range. We estimate that $68\%$ of the catalogues sources have absolute per co-ordinate astrometric uncertainties less than $\vert\Delta\alpha\vert\sim0.38\arcsec$ and $\vert\Delta\delta\vert\sim0.32\arcsec$. Our internal (filter-to-filter) per co-ordinate astrometric uncertainties are $\vert\Delta\alpha\vert\sim0.08\arcsec$ and $\vert\Delta\delta\vert\sim0.08\arcsec$. 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 $I_{\rm AB}<24.0$. 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 $I_{\rm AB}<24.0$. 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 $z\sim1$ and beyond.

Key words: galaxies: general -- astronomical data bases: miscellaneous -- surveys -- cosmology: large-scale structure of Universe

Offprint request: H. J. McCracken, hjmcc@bo.astro.it

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© ESO 2003