The Color-Magnitude Relation of Cluster Galaxies: Observations and Model   Predictions
  We investigate the origin of the color-magnitude relation (CMR) observed in cluster galaxies by using a combination of cosmological N-body/SPH simulations of galaxy clusters, and a semi-analaytic model of galaxy formation (Lagos, Cora & Padilla 2008). Simulated results are compared with the photometric properties of early-type galaxies in the Antlia cluster (Smith Castelli et al. 2008). The good agreement obtained between observations and simulations allows us to use the information provided by the model for unveiling the physical processes that yield the tigh observed CMR. 
Noelia Jimenez, Analia Smith Castelli, Sofia A. Cora and Lilia P.   Bassino
astro-ph.GA