Dark matter halos in central and insolated galaxies.

Abstract

The first evidence of a hidden, non luminous component of the Universe came from the large discrepancy between optical and dynamical masses found in the Coma cluster by Zwicky (1933). But this finding did not produce a significant echo in the astronomical community. The alarms only turned on in the mid-70’s with studies of the dynamics of pairs of galaxies and groups that revived the stunning discrepancy between dynamical and optical masses (Einasto et al. 1974; Ostriker et al. 1974), although perhaps the most convincing piece of evidence came from the fact that the rotation curves of late-type galaxies remain flat to large radii which indicates an enclosed mass growing linearly with radius (Rubin et al. 1978; Bosma 1978).