Galaxy-galaxy lensing in clusters: new results

Abstract

A synopsis of the recent results from our study of galaxy-galaxy lensing in clusters is presented. We have applied our analysis techniques to the sample of HST cluster-lenses that span a redshift range from redshift 0.18 to 0.58. We find that there is evidence that the total mass of a typical early-type cluster galaxy increases with redshift. For the lowest redshift bin, a sensible comparison can be made with field galaxies and it is found that cluster galaxies are less massive and less extended than equivalent luminosity field galaxies. This agrees broadly with the theoretical picture of tidal stripping of dark matter halos in high density cluster environments. We also find the following trends -- at a fixed luminosity both the mass-to-light ratio and the fiducial truncation radius increase with redshift from redshift 0.18 to 0.58.

contributed talk, Latex, no figures; To appear in "Gravitational Lensing: Recent Progress and Future Goals", Boston University, July 1999, ed. T.G. Brainerd and C.S. Kochanek