Cluster Selection and the Evolution of Brightest Cluster Galaxies
  The K-band Hubble diagram of Brightest Cluster Galaxies (BCGs) is presented for a large, X-ray selected cluster sample extending out to z = 0.8. The controversy over the degree of BCG evolution is shown to be due to sample selection, since the BCG luminosity depends upon the cluster environment. Selecting only the most X-ray luminous clusters produces a BCG sample which shows, under the assumption of an Einstein-de Sitter cosmology, significantly less mass growth than that predicted by current semi-analytic galaxy formation models, and significant evidence of any growth only if the dominant stellar population of the BCGs formed relatively recently (z <= 2.6). 
D. J. Burke (1 and 2), C. A. Collins (1) and R. G. Mann (3 and 4) ((1)   ARI, Liverpool John Moores University, (2) IfA, Uni...