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. 
M. H. Chan and M. C. Chu