The Dynamics of Rich Clusters of Galaxies

Abstract

An integration of the equations of motion of a 700-body system is presented. It provides a dynamical model for the growth and evolution of clustering in a bound system of galaxies with a realistic mass spectrum. Assuming that galaxy formation occurs during the initial Hubble expansion of the system, it is found that clustering grows in an extremely inhomogeneous fashion by the continual formation and amalgamation of subcondensations. The early stages of the model may shed light on the formation of inhomogeneous clusters like Virgo, while the final state gives a good fit to the gross properties of the Coma cluster in spite of the strong mass segregation which is present. A dynamically consistent mass of 2.4 by 10 to the 15th power solar masses is derived for Coma.