2002ApJ...566..103N

We investigate the influence of environment on brightest cluster galaxy (BCG) evolution using a sample of 63 clusters at 0.3≤z≤0.9 drawn primarily from the Las Campanas Distant Cluster Survey and follow-up V, I, and K' photometry. The luminosity evolution of the entire BCG sample is not adequately described by a single evolutionary model. Using the integrated light from the cluster detection as a proxy for cluster L_X and the suggestion by Burke, Collins, & Mann, we set L_X=2x10⁴⁴ ergs.s^–1 to be the division between high- and low-luminosity clusters. At high redshift (z>0.6) BCGs from low-L_X clusters are fainter, on average, than those from high-L_X clusters and are best modeled as having constant luminosity with redshift. The BCGs from high-L_X clusters are best modeled as having a stellar population that formed at large redshift (z_form>5) and is passively evolving. However, for the entire BCG population, the observed V-I and I-K' colors are well described by a single evolutionary model in which the stellar populations have z_form>5 and subsequently passively evolve. We conclude that accretion is proportionally more significant for BCGs in lower mass clusters at these redshifts (a factor of 2-4 increase in mass since z∼1 for the low-L_X systems; Aragon-Salamanca and coworkers) and that the accreted matter is in the form of systems with evolved stellar populations.