Probing the large-scale structure of the universe :

Abstract

This dissertation presents the discription of 55 bright, close (z (LESSTHEQ) 0.1) clusters of galaxies as a homogeneous sample taken from a new effort to catalogue galaxy clusters in the Southern Hemisphere. The positions of some 21,000 galaxies in clusters have been catalogued along with visual magnitudes, morphological types, position angles of extended objects and pertinent remarks. For all of the clusters, various cluster parameters have been determined and form the basis of comparative studies for these fundamental aggregates of matter in the universe.

The aims of this study are to produce a homogeneous sample of galaxy clusters measured to a uniform limiting magnitude of m(, v) = 19.0 by means of a calibrated stepscale; catalogued with accurate positions relative to nearby astrometric standard stars; morphologically classified and population typed; and statistically analysed in a uniform fashion to deduce certain cluster parameters. The cluster parameters of interest include an estimate of cluster distance, cluster center and cluster richness; galaxy distributions as a function of morphological type, magnitude distribution and core radius as determined by an isothermal gas sphere model.