1304.4717 (R. Foot)

Galactic structure explained with dissipative mirror dark matter    [PDF]

R. Foot

Dissipative dark matter, such as mirror dark matter and related hidden sector dark matter candidates, requires an energy source to stabilize dark matter halos in spiral galaxies. It has been proposed previously that supernovae might be the source of this energy. Recently, it has been argued that this mechanism might explain two galactic scaling relations inferred from observations of spiral galaxies. One of which is that $\rho_0 r_0$ is roughly constant, and another relates the galactic luminosity to $r_0$. [$\rho_0$ is the dark matter central density and $r_0$ is the core radius.] Here we derive equations for the heating of the halo via supernova energy, and the cooling of the halo via thermal bremsstrahlung. These equations are numerically solved to obtain constraints on the $\rho_0, \ r_0$ parameters appropriate for spiral galaxies. These constraints are in remarkable agreement with the aforementioned scaling relations. We examine also constraints on the dark matter halo parameters of dwarf spheroidal galaxies. As with spirals, the dark matter structure of dwarf spheroidal galaxies can be similarly explained.

View original: http://arxiv.org/abs/1304.4717