Massive neutrinos and dark halos around galaxies

Abstract

In this paper we investigate the hypothesis that hot massive neutrinos can be the main dark matter component of galactic halos. The consistency of the cosmological 's phase space density with the properties of the dark matter halos of dwarf galaxies sets an upper limit to the neutrino mass m (Tremaine & Gunn 1973; TG). Here we apply the TG argument to a very large sample (1100 objects) of high quality rotation curves of normal spirals, and calculate reliable upper limits to the neutrino mass. Unlike previous works, our estimate is dis- tance independent and holds for different Hubble Types and for thewholeluminosityrange.Wendthat,inordertobeclustered on galaxy halo scales, 's should be so massive as to violate the cosmological constraint 1. Thus, we conclude that hot neutrinos do not play a relevant role on galactic scales.