Gamma-ray background anisotropy from galactic dark matter substructure

Understand

Dark matter annihilation in galactic substructure would imprint characteristic angular signatures on the all-sky map of the diffuse gamma-ray background.

• We study the gamma-ray background anisotropy due to the subhalos and discuss detectability at Fermi Gamma-ray Space Telescope.
• We derive analytic formulae that enable to directly compute the angular power spectrum, given parameters of subhalos.
• As our fiducial subhalo models, we adopt M^{-1.9} mass spectrum, subhalos radial distribution suppressed towards the galactic center, and luminosity profile of each subhalo dominated by its smooth component.