Abstract
We present the results of the first survey of intervening Mg 0 absorption systems associated with high-z cluster galaxies. We investigated the incidence (dN/dz) of Mg 0 absorbers in < z > = 0.6 cluster galaxies from the Red-Sequence Cluster Survey. While strong (W[0] > 1.0 Å) absorbers show a significant excess (up to 10×), weak (W[0] < 0.3 Å) absorbers conform to the field statistics. We argue that this dichotomy could be explained if cluster galaxies that give rise to weak Mg 0 absorption have their cold halos truncated as a consequence of environmental effects.
