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Title: Dark matter subhalos and unidentified sources in the Fermi 3FGL source catalog

Journal Article · · Journal of Cosmology and Astroparticle Physics
 [1]; ;  [2];  [3]
  1. Anton Pannekoek Institute, University of Amsterdam, Amsterdam (Netherlands)
  2. GRAPPA, University of Amsterdam, Amsterdam (Netherlands)
  3. Institute for Computational Sciences, University of Zürich, Zürich (Switzerland)

If dark matter consists of weakly interacting massive particles (WIMPs), dark matter subhalos in the Milky Way could be detectable as gamma-ray point sources due to WIMP annihilation. In this work, we perform an updated study of the detectability of dark matter subhalos as gamma-ray sources with the Fermi Large Area Telescope (Fermi LAT). We use the results of the Via Lactea II simulation, scaled to the Planck 2015 cosmological parameters, to predict the local dark matter subhalo distribution. Under optimistic assumptions for the WIMP parameters—a 40 GeV particle annihilating to b b-bar with a thermal cross-section, as required to explain the Galactic center GeV excess—we predict that at most ∼ 10 subhalos might be present in the third Fermi LAT source catalog (3FGL). This is a smaller number than has been predicted by prior studies, and we discuss the origin of this difference. We also compare our predictions for the detectability of subhalos with the number of subhalo candidate sources in 3FGL, and derive upper limits on the WIMP annihilation cross-section as a function of the particle mass. If a dark matter interpretation could be excluded for all 3FGL sources, our constraints would be competitive with those found by indirect searches using other targets, such as known Milky Way satellite galaxies.

OSTI ID:
22667572
Journal Information:
Journal of Cosmology and Astroparticle Physics, Vol. 2016, Issue 05; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
Country of Publication:
United States
Language:
English