Cosmic gamma-ray background from dark matter annihilation
- Creators
- Ando, Shin'ichiro
Abstract
High-energy photons from pair annihilation of dark matter particles contribute to the cosmic gamma-ray background (CGB) observed in a wide energy range. The precise shape of the energy spectrum of CGB depends on the nature of dark matter particles. In order to discriminate between the signals from dark matter annihilation and other astrophysical sources, however, the information from the energy spectrum of CGB may not be sufficient. We show that dark matter annihilation not only contributes to the mean CGB intensity, but also produces a characteristic anisotropy, which provides a powerful tool for testing the origins of the observed CGB. We show that the expected sensitivity of future gamma-ray detectors such as GLAST should allow us to measure the angular power spectrum of CGB anisotropy, if dark matter particles are supersymmetric neutralinos and they account for most of the observed mean intensity. As the intensity of photons from annihilation is proportional to the density squared, we show that the predicted shape of the angular power spectrum of gamma rays from dark matter annihilation is different from that due to other astrophysical sources such as blazars, whose intensity is linearly proportional to density. Therefore, the angular power spectrum of the CGB provides a "smoking-gun" signature of gamma rays from dark matter annihilation.
Additional Information
Copyright © Institute of Physics and IOP Publishing Limited 2007. Journal of Physics: Conference Series 60 (2007) -- Proceedings of the TeV Particle Astrophysics II Workshop, 28–31 August 2006, Madison, WI, USA http://www.iop.org/EJ/toc/1742-6596/60/1Files
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Additional details
- Eprint ID
- 8066
- Resolver ID
- CaltechAUTHORS:ANDjpcs07
- Created
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2007-07-23Created from EPrint's datestamp field
- Updated
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2022-07-12Created from EPrint's last_modified field