Redshifts and morphology of galaxies in the Coma cluster

By new observations of redshift and morphology, a sample of galaxies brighter than m/subp/=15.8 is nearly completed out to radial distance of 2/sup degree/./sub /79 from the center of the Coma cluster. The redshift results show that the line-of-sight velocity dispersion first decreases and then increases again with distance from the cluster center with a mean value of sigma/subv/=896 km s-1. A marginally positive test for solid body rotation of 85plus-or-minus66 km s-1 degree -1 is also found. These results are consistent with numerical models of partially relaxed systems. The morphological study shows that the relative number of spiral and irregular galaxies increases with radial distance. This seem consistent with the existence of a hot intracluster medium. However, an alternative view, that the elliptical and spiral galaxies form independent systems, cannot be excluded at this time. (auth)