Effect of Black Holes in Local Dwarf Spheroidal Galaxies on Gamma-Ray
  Constraints on Dark Matter Annihilation
  Recent discoveries of optical signatures of black holes in dwarf galaxies
indicates that low-mass galaxies can indeed host intermediate massive black
holes. This motivates the assessment of the resulting effect on the host dark
matter density profile, and the consequences for the constraints on the plane
of the dark matter annihilation cross section versus mass, stemming from the
non-observation of gamma rays from local dwarf spheroidals with the Fermi Large
Area Telescope. We compute the density profile using three different
prescriptions for the black hole mass associated with a given spheroidal
galaxy, and taking into account the cutoff to the density from dark matter
pair-annihilation. We find that the limits on the dark matter annihilation rate
from observations of individual dwarfs are enhanced by factors of a few up to
$10^6$, depending on the specific galaxy, on the black hole mass prescription,
and on the dark matter particle mass. We estimate limits from combined
observations of a sample of 15 dwarfs, for a variety of assumptions on the
dwarf black hole mass and on the dark matter density profile prior to adiabatic
contraction. We find that if black holes are indeed present in local dwarf
spheroidals, then, independent of assumptions, (i) the dark matter
interpretation of the Galactic center gamma-ray excess would be conclusively
ruled out, (ii) wino dark matter would be excluded up to masses of about 3 TeV,
and (iii) vanilla thermal relic WIMPs must be heavier than 100 GeV.
