Cluster-Cluster Lensing in Abell 2152

Abstract

We discuss lensing properties of the nearby cluster Abell 2152. Recent work shows that Abell 2152 is actually the projection of two different clusters, one of which is a Hercules supercluster member at z=0.043, while the other is more than 3 times as distant. The cluster centers have a projected separation of only 2.4 arcmin, and our data indicate that the foreground cluster lenses members of the background one. We have an ongoing program to measure the magnification of the fundamental plane in the background cluster. The magnification of this standard rod will provide an estimate of the foreground cluster mass free from the uncertainty of the mass-sheet degeneracy which affects mass estimates based on weak shear.