Abstract : A search for a very-high-energy (VHE; >= 100 GeV) gamma-ray signal from self-annihilating particle Dark Matter (DM) is performed towards a region of projected distance r ~ 45-150 pc from the Galactic Center. The background-subtracted gamma-ray spectrum measured with the High Energy Stereoscopic System (H.E.S.S.) gamma-ray instrument in the energy range between 300 GeV and 30 TeV shows no hint of a residual gamma-ray flux. Assuming conventional Navarro-Frenk-White (NFW) and Einasto density profiles, limits are derived on the velocity-weighted annihilation cross section < \sigma v> as a function of the DM particle mass. These are among the best reported so far for this energy range. In particular, for the DM particle mass of ~1 TeV, values for <\sigma v> above 3 * 10^(-25) cm^3 s^(-1) are excluded for the Einasto density profile. The limits derived here differ much less for the chosen density profile parametrizations, as opposed to limits from gamma-ray observations of dwarf galaxies or the very center of the Milky Way, where the discrepancy is significantly larger.
http://hal.in2p3.fr/in2p3-00580801
Contributeur : Claudine Bombar
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Soumis le : mardi 29 mars 2011 - 12:12:43
Dernière modification le : jeudi 12 avril 2018 - 01:48:41
A. Abramowski, Fabio Acero, F. Aharonian, A. G. Akhperjanian, G. Anton, et al.. Search for a Dark Matter annihilation signal from the Galactic Center halo with H.E.S.S. Physical Review Letters, American Physical Society, 2011, 106, pp.161301. 〈10.1103/PhysRevLett.106.161301〉. 〈in2p3-00580801〉
