Speaker
douglas spolyar
(FNAL)
Description
10 to 10^5 solar mass black holes with dark matter spikes that formed in early
minihalos and still exist in our Milky Way Galaxy today are examined in light of recent
data from the Fermi Gamma-Ray Space Telescope (FGST). The dark matter spikes
surrounding black holes in our Galaxy are sites of significant dark matter annihilation.
We examine the signatures of annihilations into gamma-rays, electrons and
positrons, and neutrinos. We find that some significant fraction of the point sources
detected by FGST might be due to dark matter annihilation near black holes in our
Galaxy. We obtain limits on the properties of dark matter annihilations in the spikes
using the information in the FGST First Source Catalog as well as the diffuse gamma-
ray flux measured by FGST. We determine the maximum fraction of high redshift
minihalos that could have hosted the formation of the first generation of stars and,
subsequently, their black hole remnants. The strength of the limits depends on the
choice of annihilation channel and black hole mass; limits are strongest for the
heaviest black holes and annhilation to $b \bar{b}$ and $W^+W^-$ final states and
also to the lightest WIMPS thus dm spikes offer strong constraints on light WIMPs
Primary author
douglas spolyar
(FNAL)
