The relative spatial distributions of high- and low-luminosity galaxies toward Coma

Abstract

The relative spatial distributions of low- and high-mass galaxies which lie in a field in the direction of the Coma Supercluster are investigated. Three tests are used to compare the distributions of high-luminosity and low-luminosity galaxies in the field: correlation functions, nearest neighbor distributions, and local density environments. All three tests indicate that the low-luminosity galaxies are significantly less confined to the structure defined by the luminous galaxies than are the luminous galaxies themselves. Several galaxies in the low-luminosity subsample are within voids. These findings lend support to various models for the formation of large-scale structure that include biased galaxy formation. In particular, the ratio of the amplitudes of the correlation functions for dwarfs and giants agrees closely with the predictions of the cold dark matter models of White et al. (1987). 54 refs.