Bonn 2010 – wissenschaftliches Programm

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T: Fachverband Teilchenphysik

T 92: Gammaastronomie I

T 92.7: Vortrag

Montag, 15. März 2010, 18:20–18:35, HG VII

Constraints on SUSY dark matter from H.E.S.S. observations of dwarf spheroidal galaxies — •Björn Opitz — Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg

Eighty per cent of the matter content of the Universe is "dark", i.e. it is only detected by its gravitational effects. One class of dark matter candidate particles is formed by "WIMPs", weakly interacting massive (∼100 GeV) particles that arise, e.g., in supersymmetric theories. The decay chain of final-state particles from WIMP self-annihilations may produce very high energy (VHE) photons detectable by air Cherenkov telescopes like H.E.S.S.

Dwarf spheroidal galaxies are the most dark matter-dominated galaxies in the known Universe. With high mass-to-luminosity ratios and little expected astrophysical background, they are prime targets for dark matter searches with VHE gamma-ray telescopes. Their dark matter content and halo profiles can be derived from stellar velocity dispersion measurements. H.E.S.S. observations of nearby dwarf spheroidals can be used to place limits on the self-annihilation cross-section of WIMPs with masses of a few 100 GeV. These limits constrain dark matter models with non-thermally produced WIMPs or strong boost factors from effects like Sommerfeld enhancement.

Limits on Wino-like neutralinos from anomaly-mediated SUSY breaking models are discussed in the context of H.E.S.S. observations of dwarf spheroidal galaxies.