Optical ( VRI ) Photometry in the Field of the Galaxy Cluster AC 118 at z = 0 . 31 ⋆

We present new photometric V-, R-and I-band data for the rich galaxy cluster AC 118 at z = 0.31. The new photometry covers an area of 8.6×8.6 arcmin 2 , corresponding to 2.9×2.9 Mpc 2 (H0 = 50 km s −1 Mpc −1 , q0 = 0.5 and Λ = 0). The data have been collected for a project aimed at studying galaxy evolution through the color-magnitude relation and the fundamental plane. We provide a catalogue including all the sources (N = 1219) detected in the cluster field. The galaxy sample is complete to V = 22.8 mag (N gal = 569), R = 22.3 mag (N gal = 669) and I = 20.8 mag (N gal = 425). We give aperture magnitudes within a fixed aperture of 4.4 arcsec and Kron magnitudes. We also give photo-metric redshifts for 489 sources for which additional U-and K-band photometry is available. We derive and discuss the V-and R-band luminosity functions. The catalogue, which is distributed in electronic form, is intended as a tool for studies in galaxy evolution.