A SEARCH FOR A DARK MATTER ANNIHILATION SIGNAL TOWARD THE CANIS MAJOR OVERDENSITY WITH HESS

作者：Aharonian F^*; Akhperjanian A G; de Almeida U Barres; Bazer Bachi A R; Behera B; Benbow W; Bernloehr K; Boisson C; Bochow V; Borrel V; Braun I; Brion E; Brucker J; Brun P; Buehler R; Bulik T; Buesching I; Boutelier T; Carrigan S; Chadwick P M; Charbonnier A; Chaves R C G; Cheesebrough A; Chounet L M; Clapson A C; Coignet G; Costamante L; Dalton M; Degrange B; Deil C; Dickinson H J; Djannati Atai A; Domainko W

来源：Astrophysical Journal, 2009, 691(1): 175-181.

DOI：10.1088/0004-637X/691/1/175

• dark matter
• galaxies: dwarf
• gamma rays: observations

A search for a dark matter (DM) annihilation signal into gamma-rays toward the direction of the Canis Major (CMa) overdensity is presented. The nature of CMa is still controversial and one scenario represents it as a dwarf galaxy, making it an interesting candidate for DM annihilation searches. A total of 9.6 hr of high-quality data were collected with the H.E.S.S. array of Imaging Atmospheric Cherenkov Telescopes, and no evidence for a very high energy gamma-ray signal is found. Upper limits on the CMa dwarf galaxy mass of the order of 10(9) M(circle dot) are derived at the 95% confidence level (CL) assuming neutralino masses in the range 500 GeV-10 TeV and relatively large annihilation cross sections. Constraints on the velocity-weighted annihilation cross section are calculated for specific weakly interacting massive-particle scenarios, using a Navarro-Frenk-White model for the DM halo profile and taking advantage of numerical simulations of hierarchical structure formation. Assuming a total halo mass of 3 x 10(8) M(circle dot), 95% CL exclusion limits of the order of 5 x 10(-24) cm(3) s(-1) are reached in the 500 GeV-10 TeV DM particle mass interval.

• 出版日期2009-1-20
• 单位中国地震局; 西北大学