Composite luminosity function of cluster galaxies
  We constructed the composite Luminosity Function (LF) of cluster galaxies in the g,r and i bands from the photometry of a mixed (Abell and X-ray selected) sample of the cores of 65 clusters, ranging in redshift from 0.05 to 0.25. The composite LF has been obtained from complete samples of ~2200 galaxies in the magnitude range -23<M<-17.5 (-18 in i). Cluster membership has been determined on the basis of color-color plots for each cluster and the resulting outlier counts have been checked against field counts in the same bands. We find that the galaxy density of the environment determines the shape of the LF, in the sense that bright galaxies are more abundant in dense clusters. 
Bianca Garilli (1), Dario Maccagni(1), Stefano Andreon(2) ((1)   Istituto di Fisica Cosmica G. Occhialini, (2) Osservatorio ...