Massive black holes lurking in Milky Way satellites
  As massive black holes (MBHs) grow from lower-mass seeds, it is natural to
expect that a leftover population of progenitor MBHs should also exist in the
present universe. Dwarf galaxies undergo a quiet merger history, and as a
result, we expect that dwarfs observed in the local Universe retain some
`memory' of the original seed mass distribution. Consequently, the properties
of MBHs in nearby dwarf galaxies may provide clean indicators of the efficiency
of MBH formation. In order to examine the properties of MBHs in dwarf galaxies,
we evolve different MBH populations within a Milky Way halo from high-redshift
to today. We consider two plausible MBH formation mechanisms: `massive seeds'
formed via gas-dynamical instabilities and a Population III remnant seed model.
`Massive seeds' have larger masses than PopIII remnants, but form in rarer
hosts. We dynamically evolve all halos merging with the central system, taking
into consideration how the interaction modifies the satellites, stripping their
outer mass layers. We compute different properties of the MBH population hosted
in these satellites. We find that for the most part MBHs retain the original
mass, thus providing a clear indication of what the properties of the seeds
were. We derive the black hole occupation fraction (BHOF) of the satellite
population at z=0. MBHs generated as `massive seeds' have large masses that
would favour their identification, but their typical BHOF is always below 40
per cent and decreases to less than per cent for observed dwarf galaxy sizes.
In contrast, Population III remnants have a higher BHOF, but their masses have
not grown much since formation, inhibiting their detection.
