Cosmological lower bound on dark matter masses from the soft gamma-ray background
- Department of Astronomy, University of Texas at Austin, 1 University Station, C1400, Austin, Texas 78712 (United States)
Motivated by a recent detection of 511 keV photons from the center of our Galaxy, we calculate the spectrum of the soft {gamma}-ray background of the redshifted 511 keV photons from cosmological halos. Annihilation of dark matter particles into electron-positron pairs makes a substantial contribution to the {gamma}-ray background. Mass of such dark matter particles must be < or approx. 100 MeV so that resulting electron-positron pairs are nonrelativistic. On the other hand, we show that in order for the annihilation not to exceed the observed background, the dark matter mass needs to be > or approx. 20 MeV. We include the contribution from the active galactic nuclei and supernovae. The halo substructures may increase the lower bound to > or approx. 60 MeV.
- OSTI ID:
- 20705783
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 71, Issue 2; Other Information: DOI: 10.1103/PhysRevD.71.021303; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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