ATIC, PAMELA, HESS, and Fermi data and nearby dark matter subhalos

Journal Article · Mon Jun 15 04:00:00 EDT 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.79.123517· OSTI ID:21300948

Kuhlen, Michael; Malyshev, Dmitry ^[1]

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1. Institute for Advanced Study, Einstein Drive, Princeton, New Jersey 08540 (United States)

We study the local flux of electrons and positrons from annihilating dark matter (DM), and investigate how its spectrum depends on the choice of DM model and inhomogeneities in the DM distribution. Below a cutoff energy, the flux is expected to have a universal power-law form with an index n{approx_equal}-2. The cutoff energy and the behavior of the flux near the cutoff is model dependent. The dependence on the DM host halo profile may be significant at energies E<100 GeV and leads to softening of the flux n<-2. There may be additional features at high energies due to the presence of local clumps of DM, especially for models in which the Sommerfeld effect boosts subhalo luminosities. In general, the flux from a nearby clump gives rise to a harder spectrum of electrons and positrons, with an index n>-2. Using the Via Lactea II simulation, we estimate the probability of such subhalo effects in a generic Sommerfeld-enhanced model to be at least 4%, and possibly as high as 15% if subhalos below the simulation's resolution limit are accounted for. We discuss the consequences of these results for the interpretation of the ATIC, PAMELA, HESS, and Fermi data, as well as for future experiments.

• OSTI ID: 21300948
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 12 Vol. 79; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANNIHILATION
DISTRIBUTION
ELECTRONS
GEV RANGE 10-100
LUMINOSITY
NONLUMINOUS MATTER
POSITRONS
RESOLUTION
SIMULATION
SPECTRA