Galactic structure explained with dissipative mirror dark matter

Abstract

Dissipative dark matter, such as mirror dark matter and related hidden-sector dark matter candidates, require an energy source to stabilize dark matter halos in spiral galaxies. It has been proposed previously that supernovae could 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 these is that ${\ensuremath{\rho}}_{0}{r}_{0}$ is roughly constant, and the other relates the galactic luminosity to ${r}_{0}$. (${\ensuremath{\rho}}_{0}$ 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 ${\ensuremath{\rho}}_{0}$, ${r}_{0}$ parameters appropriate for spiral galaxies. These constraints are in remarkable agreement with the aforementioned scaling relations.