Milos Milosavljevic (Rutgers)
"Black hole mergers and implications for dark matter halo cores"
Accumulation of baryons at the center of a halo can displace the dark
matter, converting singular density cusps into low-density cores. The
displaced mass can be of order 10 M_b with M_b the mass of the infalling
population. If M_b is identified with the masses of the black holes
currently observed at the centers of bright galaxies, predicted core radii
are at most a few hundred pc. Dark matter distribution at the center of a
galaxy is shown to be strongly dependent on the galaxy's merger history.
The effect of black hole mergers on sharp dark matter overdensities
surrounding compact objects ("spikes") is most severe. In particular, the
predicted flux of WIMP annihilation photons from such a spike at the
Galactic center is several orders of magnitude smaller than in models that
ignore the effects of SBHs and mergers.
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