Angular signatures of dark matter in the diffuse gamma ray background

作者：Hooper Dan^*; Serpico Pasquale D

来源：Journal of Cosmology and Astroparticle Physics, 2007, (6): 013.

DOI：10.1088/1475-7516/2007/06/013

• dark matter
• high energy photons

Dark matter annihilating in our galaxy's halo and elsewhere in the universe is expected to generate a diffuse flux of gamma rays, potentially observable with next generation satellite-based experiments, such as GLAST. In this paper, we study the signatures of dark matter in the angular distribution of this radiation, in particular the deterministic ones. We discuss the effect, pertaining to the extragalactic contribution, of the motion of the solar system with respect to the cosmological rest frame, and anisotropies due to the structure of our local universe. For the gamma ray flux from dark matter in our own galactic halo, we discuss the effects of the offset position of the solar system, the Compton-Getting effect, the asphericity of the Milky Way halo, and the signatures of nearby substructure. We explore the prospects for the detection of these features by the GLAST satellite and find that, if similar to 10% or more of the diffuse gamma ray background observed by EGRET is the result of dark matter annihilations, then GLAST should be sensitive to anisotropies at the sub-per cent level. Such precision would be sufficient to detect many, if not all, of the signatures discussed in this paper.

• 出版日期2007-6