Deep and wide field imaging of the Coma cluster:: the data

We have obtained deep and wide field imaging of the Coma cluster of galaxies with the CFH12K camera at CFHT in the B, V, R and I filters. In this paper, we present the observations, data reduction, catalogs and first scientific results. We investigated the quality of our data by internal and external literature comparisons. We also checked the realisation of the observational requirements we set. Our observations cover two partially overlapping areas of 42 x 28 arcmin(2), leading to a total area of 0.72 x 0.82 deg(2). We have produced catalogs of objects that cover a range of more than 10 mag. and are complete at the 90% level at B similar to 25, V similar to 24, R similar to 24 and I similar to 23.5 for stellar-like objects, and at B similar to 22, V similar to 21, R similar to 20.75 and I similar to 20.5 for faint low-surface-brightness galaxy-like objects. Magnitudes are in good agreement with published values from R similar to 16 to R similar to 25. The photometric uncertainties are of the order of 0.1 mag at R similar to 20 and of 0.3 mag at R similar to 25. Astrometry is accurate to 0.5 arcsec and also in good agreement with published data. Our catalog provides a rich dataset that can be mined for years to come to gain new insights into the formation and evolution of the Coma cluster and its galaxy population. As an illustration of the data quality, we examine the bright part of the Colour Magnitude Relation (B-R versus R) derived from the catalog and find that it is in excellent agreement with that derived for galaxies with redshifts in the Coma cluster, and with previous CMRs estimated in the literature.