Dissipative dark matter and the rotation curves of dwarf galaxies

TL;DR

This paper explores how dissipative, self-interacting dark matter, influenced by supernova heating, can explain the rotation curves and core profiles of dwarf galaxies by relating dark matter distribution to baryonic activity.

Contribution

It advances the dissipative dark matter model by incorporating observed supernova distributions to predict dark matter halos and compare with dwarf galaxy rotation curves.

Findings

Dark matter halos can reach equilibrium states balancing heating and cooling.

The model successfully fits rotation curves of dwarf galaxies in the LITTLE THINGS sample.

Dark matter density profiles correlate with supernova distributions.

Abstract

There is ample evidence from rotation curves that dark matter halos around disk galaxies have nontrivial dynamics. Of particular significance are: a) the cored dark matter profile of disk galaxies, b) correlations of the shape of rotation curves with baryonic properties, and c) Tully-Fisher relations. Dark matter halos around disk galaxies may have nontrivial dynamics if dark matter is strongly self interacting and dissipative. Multicomponent hidden sector dark matter featuring a massless `dark photon' (from an unbroken dark $U(1)$ gauge interaction) which kinetically mixes with the ordinary photon provides a concrete example of such dark matter. The kinetic mixing interaction facilitates halo heating by enabling ordinary supernovae to be a source of these `dark photons'. Dark matter halos can expand and contract in response to the heating and cooling processes, but for a sufficiently isolated halo could have evolved to a steady state or `equilibrium' configuration where heating and cooling rates locally balance. This dynamics allows the dark matter density profile to be related to the distribution of ordinary supernovae in the disk of a given galaxy. In a previous paper a simple and predictive formula was derived encoding this relation. Here we improve on previous work by modelling the supernovae distribution via the measured UV and $H\alpha$ fluxes, and compare the resulting dark matter halo profiles with the rotation curve data for each dwarf galaxy in the LITTLE THINGS sample. The dissipative dark matter concept is further developed and some conclusions drawn.