Angular Signatures of Dark Matter in the Diffuse Gamma Ray Spectrum
Feb, 200712 pages
Published in:
- JCAP 06 (2007) 013
e-Print:
- astro-ph/0702328 [astro-ph]
Report number:
- FERMILAB-PUB-07-038-A
Citations per year
Abstract: (arXiv)
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 article, we study the signatures of dark matter in the angular distribution of this radiation. Pertaining to the extragalactic contribution, we discuss the effect 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 ~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 down to the 0.1% level. Such precision would be sufficient to detect many, if not all, of the signatures discussed in this paper.- 95.85.Pw
- 98.70.Vc
- 95.35.+d
- dark matter: annihilation
- gamma ray: flux
- gamma ray: background
- angular distribution: signature
- galaxy
- counters and detectors: satellite
- numerical calculations
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