The luminosity-halo mass relation for brightest cluster galaxies

We examine the central galaxy luminosity-host halo mass relation for 54 brightest group galaxies (BGGs) and 92 brightest cluster galaxies (BCGs) at z < 0.1 and present the first measurement of this relation for a sample of known BCGs at 0.1 < z < 0.8((z)over bar similar to 0.3). At z < 0.1 we find L-K alpha M-200(0.24 +/- 0.08) for the BCGs and the early-type BGGs in groups with extended X-ray emission and L-K alpha M-200(0.11 +/- 10) for the BCGs alone. At 0.1 < z < 0.8 we find L-K alpha M-200(0.28 +/- 0.11). We conclude that there is no evidence for evolution in this relationship between z < 0.1 and z < 0.8: BCG growth appears to still be limited by the time-scale for dynamical friction at these earlier times, not proceeding according to the predictions of present semianalytic models.