The Most Dark Matter Dominated Galaxies: Predicted Gamma-ray Signals from the Faintest Milky Way Dwarfs

Abstract

We use kinematic data from three new, nearby, extremely low-luminosity Milky Way dwarf galaxies (Ursa Major II, Willman 1, and Coma Berenices) to constrain the properties of their dark matter halos, and from these make predictions for the gamma-ray flux from annihilation of dark matter particles in these halos. We show that these 10^3 solar luminosity dwarfs are the most dark matter dominated galaxies in the Universe, with total masses within 100 pc in excess of 10^6 solar masses. Coupled with their relative proximity, their large masses imply that they should have mean gamma-ray fluxes comparable to or greater than any other known satellite galaxy of the Milky Way. Our results are robust to both variations of the inner slope of the density profile and the effect of tidal interactions. The fluxes could be boosted by up to two orders of magnitude if we include the density enhancements caused by surviving dark matter substructure.

9 pages, 4 figures. Minor typos corrected

References in corpus (14)

• The Kinematics of the Ultra-Faint Milky Way Satellites: Solving the Missing Satellite Problem
• Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions
• The Observed properties of Dark Matter on small spatial scales
• The Tidal Evolution of Local Group Dwarf Spheroidals
• Velocity Dispersion Profiles of Seven Dwarf Spheroidal Galaxies
• Precise constraints on the dark matter content of Milky Way dwarf galaxies for gamma-ray experiments
• The Cold Dark Matter Halos of Local Group Dwarf Spheroidals
• The fraction of binary systems in the core of thirteen low-density Galactic globular clusters
• Stellar kinematics and metallicities in the Leo I dwarf spheroidal galaxy -- wide field implications for galactic evolution
• Mass modelling of dwarf spheroidal galaxies: the effect of unbound stars from tidal tails and the Milky Way
• Can Astrophysical Gamma Ray Sources Mimic Dark Matter Annihilation in Galactic Satellites?
• Proper motion of gamma-rays from microhalo sources
• Dark Matter and the CACTUS Gamma-Ray Excess from Draco
• Dark Matter annihilation in Draco: new considerations of the expected gamma flux

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