Evolution in Galaxy Nuclei. I. Comparison of the Coma and Virgo Clusters

Abstract

The correlation of nuclear magnitude with redshift in the Coma and Virgo Clusters is discussed. The two clusters are combined in a fitting process to determine a differential distance modulus of 3.47 ±0.05. Hubble velocities of the clusters are found to be 1284 ±45 and 6344 ±70. For a Virgo Cluster distance of 14.8 Mpc the Hubble constant is H = 86.3 ±3, subject to the usual major systematic errors. The effect of the redshift -magnitude correlation on the luminosity functions of the Coma and Virgo Cluster is discussed and can account for observed nonuniformity in the luminosity functions. The observed redshift distribution within clusters is interpreted as a uniform Hubble velocity upon which is superimposed a differential redshift not due to mass center motion. A combination of gravitational redshifts and radial mass motion induced in an evolving nuclear gravitational potential field is suggested to produce the differential redshifts. Galaxies are viewed as expanding systems evolving from dense cores with the redshift -magnitude correlation representing a form of evolutionary track. Clusters as a whole can be dynamically stable. The outflow of material is a source of inter- galactic bridges, intergalactic stellar haze, and various phenomena observed in galaxy envelopes. The concept of evolving galaxies has major consequences on cosmological models. Age dispersion in clusters and possible evolutionary corrections to galaxy redshifts and total luminosities both suggest that a new approach to a steady state concept is possible.