Neutrino Star as Galactic Cluster Dark Halo

Recent Strong lensing data and rotation curves of dwarf galaxies indicate that many galactic clusters may have a soft core instead of a central cusp in their density distribution. This result challenges the standard CDM (Cold Dark Matter) theory prediction based on N-body simulations. We find that the observed density profile is consistent with that of a spherical gas of degenerate fermions such as neutrinos in hydrostatic equilibrium. Also, we compare two different models of the dark matter halo and their predictions for the hot gas profile.