The mean mass density estimated from the Kirshner, Oemler, Schechter galaxy redshift sample

Abstract

The sample of 166 galactic redshifts obtained by Kirshner, Oemler, and Schechter (1978) to a limiting J magnitude of 15 is used to estimate the rms relative peculiar velocity of nearby galaxies. It is assumed that the galaxy distribution is a useful measure of the mass distribution and that galaxy clustering is statistically stable. Together with these assumptions, the estimated rms relative peculiar velocity yields a preliminary value for the cosmological density parameter (Omega) of 0.4 + or - 0.2. It is suggested that a rather modest increase in sample size might yield a credible value for the mean mass density in clustered matter.