Constraints on Dark Matter Properties from Observations of Milky Way Satellite Galaxies

We perform a comprehensive study of Milky Way (MW) satellite galaxies to constrain the fundamental properties of dark matter (DM). This analysis fully incorporates inhomogeneities in the spatial distribution and detectability of MW satellites and marginalizes over uncertainties in the mapping between galaxies and DM halos, the properties of the MW system, and the disruption of subhalos by the MW disk. Our results are consistent with the cold, collisionless DM paradigm and yield the strongest cosmological constraints to date on particle models of warm, interacting, and fuzzy dark matter. At 95% confidence, we report limits on (i) the mass of thermal relic warm DM, m(WDM) > 6.5 keV (free-streaming length, lambda(fs) less than or similar to 10 h(-1) kpc), (ii) the velocity-independent DM-proton scattering cross section, sigma(0) < 8.8 x 10(-29) cm(2) for a 100 MeV DM particle mass [DM-proton coupling, c(p) less than or similar to (0.3 GeV)(-2)], and (iii) the mass of fuzzy DM, m(phi) > 2.9 x 10(-21) eV (de Broglie wavelength, lambda(dB) less than or similar to 0.5 kpc). These constraints are complementary to other observational and laboratory constraints on DM properties.

Automated summary

The study on Milky Way satellite galaxies provides strong cosmological constraints on various particle models of dark matter, supporting the cold, collisionless dark matter paradigm. Limits are reported on the mass of thermal relic warm dark matter, velocity-independent dark matter-proton scattering cross section, and the mass of fuzzy dark matter, complementing other observational and laboratory constraints on dark matter properties.