Speaker
Mr
Mattia Fornasa
(Instituto de Astrofisica de Andalucia (IAA - CSIC))
Description
Using the first 22 months of data, the Fermi-LAT collaboration measured the angular
spectrum (APS) of anisotropies in the diffuse gamma-ray background. Results indicate
the detection of angular signal with a significance of few sigma. The APS is
consistent with being independent from multipole (for multipoles larger than 154) and
this is compatible with the contribution from one or more populations of unresolved,
unclustered gamma-ray emitters.
In this study we use Fermi-LAT measurement of the APS to constrain a possible
contribution from Dark Matter (DM) to the APS. The DM distribution is modeled
exploiting the results of the most recent N-body simulations, considering both the
contribution of extragalactic halos and subhalos (from Millennium-II) and of Galactic
substructures (from Aquarius). Both the cases of an annihilating and decaying DM
candidate are considered. Moreover, with the use of the Fermi Science Tools, these DM
maps serve as templates to produce mock gamma-ray count maps for DM gamma-ray
emission. The APS will then be computed and compared to the Fermi-LAT results in
order to derive constraints on the DM particle physics properties. We also estimate
the uncertainties on the APS due our imperfect knowledge of DM distribution, as well
as the possible systematic due to a residual contamination of the Galactic foreground.
Primary author
Mr
Mattia Fornasa
(Instituto de Astrofisica de Andalucia (IAA - CSIC))
