New measurements of anisotropies in the gamma-ray sky and their dark matter interpretation

Mayo 9, 2016
De 3:00pm hasta 4:00pm

IFT Seminar Room/Red Room

Theoretical Physics, general interest
German A. Gomez-Vargas
Universidad Catolica (Chile)

IFT Seminar Room/Red Room


The isotropic gamma-ray background arises from the contribution of unresolved sources, including members of confirmed source classes as well as proposed gamma-ray emitters such as dark matter annihilation and decay. Clues about the properties of the contributing sources are imprinted in the anisotropy characteristics of the gamma-ray background. I will present preliminary results on a Fermi-MultiDark project where we use more than 81 months of Pass 7 reprocessed data from the Fermi Large Area Telescope to perform a measurement of the anisotropy angular power spectrum of the gamma-ray background. We analyze energies between 0.5 and 500 GeV, extending the range considered in the previous measurement, based on 22 months of data. We also compute, for the first time, the cross-correlation angular power spectrum between different energy bins. Using state-of-the-art numerical simulations to model the dark matter distribution, we constrain the contribution from dark matter annihilation and decay in Galactic and extragalactic structures to the measured anisotropy of the gamma-ray background.