15–19 Sept 2014
DESY Hamburg
Europe/Berlin timezone

dSphs, J-factors and DM limits

19 Sept 2014, 10:00
20m
ZOQ, Building 90, Seminar Room (DESY Hamburg)

ZOQ, Building 90, Seminar Room

DESY Hamburg

Luruper Chaussee 149, 22761 Hamburg, Germany

Speaker

Mr Mauro Valli (SISSA, INFN)

Description

Dwarf spheroidal galaxies (dSph) are dominated dark matter (DM) astrophysical objects which allow us to put tight constraints on the velocity averaged annihilation cross-section of weakly interacting massive particles (WIMPs). Such bounds, coming from the observation of dSphs in the gamma-ray band, depend crucially on the mass modelling of this peculiar class of galaxies. We will review the moment-based Jeans analysis to get quantitative informations about the mass halo of dSphs and shed new lights on the astrophysical uncertainty present in the game, stressing the underlying assumptions involved. In particular, inverting the Jeans equation, we will show a semi-analytic approach to assess the biggest possible span of the astrophysical uncertainty in dSph mass modelling , deriving dSph halo densities and the intimately related "J-factors" as functions of the stellar orbital anisotropy profile. As a final remark of the results of our work, a weaker bound on the DM annihilation cross-section with respect to the latest one given by FERMI-LAT collaboration turns out to be highly plausible.

Primary author

Mr Mauro Valli (SISSA, INFN)

Co-author

Mr Piero Ullio (SISSA, INFN)

Presentation materials

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