Search for dark matter annihilation signatures in H.E.S.S. observations of dwarf spheroidal galaxies
Date
2014Author
Abramowski, A.
Böttcher, M.
Davids, I.D.
Ivascenko, A.
Krüger, P.P.
Pekeur, N.W.
Spanier, F.
Sushch, I.
Venter, C.
Vorster, M.
H.E.S.S. Collaboration
Metadata
Show full item recordAbstract
Dwarf spheroidal galaxies of the Local Group are close satellites of the Milky Way characterized by a
large mass-to-light ratio and are not expected to be the site of nonthermal high-energy gamma-ray emission
or intense star formation. Therefore they are among the most promising candidates for indirect dark matter
searches. During the last years the High Energy Stereoscopic System (H.E.S.S.) of imaging atmospheric
Cherenkov telescopes observed five of these dwarf galaxies for more than 140 hours in total, searching for
TeV gamma-ray emission from annihilation of dark matter particles. The new results of the deep exposure
of the Sagittarius dwarf spheroidal galaxy, the first observations of the Coma Berenices and Fornax
dwarves and the reanalysis of two more dwarf spheroidal galaxies already published by the H.E.S.S. Collaboration, Carina and Sculptor, are presented. In the absence of a significant signal new constraints on
the annihilation cross section applicable to weakly interacting massive particles (WIMPs) are derived
by combining the observations of the five dwarf galaxies. The combined exclusion limit depends on the
WIMP mass and the best constraint is reached at 1–2 TeV masses with a cross-section upper bound of
∼ 3.9 × 10−24 cm3 s−1 at a 95% confidence level
URI
http://hdl.handle.net/10394/32085https://journals.aps.org/prd/abstract/10.1103/PhysRevD.90.112012
https://doi.org/10.1103/PhysRevD.90.112012