On minor black holes in galactic nuclei
  Small and intermediate mass black holes should be expected in galactic nuclei
as a result of stellar evolution, minor mergers and gravitational dynamical
friction. If these minor black holes accrete as X-ray binaries or
ultra-luminous X-ray sources, and are associated with star formation, they
could account for observations of many low luminosity AGN or LINERs. Accreting
and inspiralling intermediate mass black holes could provide a crucial
electromagnetic counterpart to strong gravitational wave signatures, allowing
tests of strong gravity. Here we discuss observational signatures of minor
black holes in galactic nuclei and we demonstrate that optical line ratios
observed in LINERs or transition-type objects can be produced by an ionizing
radiation field from ULXs. We conclude by discussing constraints from existing
observations as well as candidates for future study.
