New D‐σ Results for Coma Ellipticals

Abstract

We discuss D — σ results for a new sample of ellipticals in the Coma cluster. Unlike previous studies, our sample includes many ellipticals that lie well outside the cluster core. These data have been used to estimate the environmental dependence of the D — σ relation. The zero-point of the D — σ relation is found to vary by only -8% α10% from Coma’s core to a projected distance of ~4h -1 Mpc. The projected galaxian density from the core to our outermost ellipticals decreases by a factor of over 150. Thus over a very wide range of galaxian densities we find no evidence for a significant zero-point variation in the D — σ relation.