The Velocity Distribution of Galaxies in Clusters

Abstract

The observed velocity distribution in clusters of galaxies of varying richnesses is found to be consistent with an underlying Gaussian distribution law, except for some contamination by field galaxies. A procedure is developed for removing suspected field galaxies. The velocity dispersion in clusters can, therefore, be safely estimated from the sample of velocities available, after the suspected field galaxies have been removed. Subject heading: galaxies: clusters of