The Las Campanas/AAT Rich Cluster Survey II: The Environmental Dependance of Galaxy Colours in Clusters at z~0.1

Abstract

(Abridged) We present a photometric investigation of the variation in galaxy colour with environment in 11 X-ray luminous clusters at 0.07<z<0.16 taken from the Las Campanas/AAT Rich Cluster Survey. We study the properties of the galaxy populations in individual clusters and take advantage of the homogeneity of the sample to combine the clusters together to investigate weaker trends in the composite sample. We find that modal colours of galaxies lying on the colour-magnitude relation in the clusters become bluer by d(B-R)/dr_p=-0.022 \pm 0.004 from the cluster core out to a projected radius of r_p=6 Mpc; further out in radius than any previous study.....