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The Distribution and Annihilation of Dark Matter Around Black HolesWe use a Monte Carlo code to calculate the geodesic orbits of test particles around Kerr black holes, generating a distribution function of both bound and unbound populations of dark matter (DM) particles. From this distribution function, we calculate annihilation rates and observable gamma-ray spectra for a few simple DM models. The features of these spectra are sensitive to the black hole spin, observer inclination, and detailed properties of the DM annihilation cross-section and density profile. Confirming earlier analytic work, we find that for rapidly spinning black holes, the collisional Penrose process can reach efficiencies exceeding 600%, leading to a high-energy tail in the annihilation spectrum. The high particle density and large proper volume of the region immediately surrounding the horizon ensures that the observed flux from these extreme events is non-negligible.
Document ID
20160005216
Document Type
Reprint (Version printed in journal)
Authors
Schnittman, Jeremy D. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
April 20, 2016
Publication Date
June 20, 2015
Publication Information
Publication: The Astrophysical Journal
Volume: 806
Issue: 2
Subject Category
Astrophysics
Report/Patent Number
GSFC-E-DAA-TN31434
Funding Number(s)
CONTRACT_GRANT: ATP12-0139
CONTRACT_GRANT: ATP13-0077
Distribution Limits
Public
Copyright
Other
Keywords
astroparticle physics
relativistic processes
black hole physics