Anisotropies in the Diffuse Gamma-Ray Background from Dark Matter with Fermi LAT: a closer look

Understand

We perform a detailed study of the sensitivity to the anisotropies related to Dark Matter (DM) annihilation in the Isotropic Gamma-Ray Background (IGRB) as measured by the Fermi Large Area Telescope (Fermi-LAT).

• For the first time, we take into account the effects of the Galactic foregrounds and use a realistic representation of the Fermi-LAT.
• We consider DM anisotropies of extra-galactic origin and of Galactic origin (which can be generated through annihilation in the Milky Way sub-structures) as opposed to a background of anisotropies generated by sources of astrophysical origin, blazars for example.
• We find that with statistics from 5 years of observation Fermi is sensitive to a DM contribution at the level of the thermal-relic cross section depending on the DM mass and annihilation mode.