DARK-MATTER AROUND A CLUSTER OF GALAXIES UNDER THE LONG COSMIC-STRINGSCHEME

We study the formation of cluster of galaxies induced by cosmic string s in a flat universe dominated by cold dark matter. A cluster of galax ies is considered to be formed at the crossing site of three wakes of infinitely long cosmic strings. In this scheme, we investigate the dis tribution of dark matter and galaxies within and around a cluster of g alaxies. The simulated line-of-sight velocity dispersion and projected surface number density of galaxies are compared with the observations in a simplified case. Some features seem to be in good agreement with the observation, although the detailed structures require a more refi ned investigation. A characteristic pattern of density inhomogeneities is expected to exist within a cluster, which might be related to the substructures observed in many clusters of galaxies. The brightest clu ster member, such as a gE, D, or cD galaxy, is naturally expected to r eside at the cluster center in this scheme.