Discovery prospects of dwarf spheroidal galaxies for indirect dark matter searches

Abstract

We study the prospects for the Large Synoptic Survey Telescope (LSST) to find new dwarf spheroidal galaxies in the Milky Way. Adopting models of Milky-Way halo substructure and phenomenological prescriptions connecting subhalos and satellite galaxies, we obtain surface brightness distributions of $V$-band magnitude that lead us to predict that LSST will discover tens to hundreds of dwarf spheroidal galaxies above its sensitivity. The soon-to-be-discovered dwarfs will be interesting targets for indirect searches of dark matter annihilation yields. We forecast the distribution function of gamma-ray emission from dark matter annihilation in these objects, and discuss the detectability of these signals at both Fermi Large Area Telescope (LAT) and Cherenkov Telescope Array (CTA). By combining information from the predicted dwarf galaxies, we obtain an expected sensitivity to the annihilation cross section $⟨\sigma v⟩$ of $10^{-26}$ cm${}^3$ s${}^{-1}$ (for dark matter particles of mass 10 GeV with Fermi-LAT) and $5\times 10^{-24}$ cm${}^3$ s${}^{-1}$ (for dark matter particles of mass 500 GeV with CTA). We find that the current uncertainties in the mass measurement of the Milky-Way halo are relatively minor compared with the Poisson errors associated to drawing the most promising dwarfs from the underlying flux distribution.

13 pages (+ references), 6 figures. v2: minor corrections, matches version published in JCAP

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Cited by in corpus (7)

• Global fit of pseudo-Nambu-Goldstone Dark Matter
• Decaying dark matter in dwarf spheroidal galaxies: Prospects for X-ray and gamma-ray telescopes
• Gamma-ray sensitivity to dark matter subhalo modelling at high latitudes
• Search for heavy dark matter from dwarf spheroidal galaxies: leveraging cascades and subhalo models
• Harnessing the Population Statistics of Subhalos to Search for Annihilating Dark Matter
• Stellar Profile Independent Determination of the Dark Matter Distribution of the Fornax Local Group Dwarf Spheroidal Galaxy
• Bayesian WIMP detection with the Cherenkov Telescope Array