Intermediate-Mass Black Hole Feedback in Dwarf Galaxies: a View from
  Cosmological Simulations
  Black holes are usually observed to be of stellar-mass or supermassive. By
natural extension, there should be a population of Intermediate-Mass Black
Holes (IMBHs: with mass between $100$ to $10^6 M_{\odot}$) in the Universe;
which has started to been observed. An exciting claim has been made recently by
Silk (2017): that early feedback by IMBHs in gas-rich dwarf galaxies at
$z=5-8$, can potentially solve multiple dwarf galaxy problems within the
$\Lambda$-cold-dark-matter cosmology. We are performing Cosmological
Hydrodynamical Simulations of $(2 Mpc)^3$ volumes, starting from $z=100$, to
test the case for IMBHs in Dwarf Galaxies. Black holes of mass $1000 M_{\odot}$
are seeded inside halos when they reach a mass of $10^7 M_{\odot}$. The black
holes grow by accretion of gas from their surroundings and by merger with other
black holes, and consequently eject feedback energy. We analyze the simulation
output in post-processing to study the growth of the first IMBHs, and their
impact on star-formation. Our conclusions, based on numerical simulation
results, support the phenomenological ideas made by Silk (2017). IMBHs at the
centers of dwarf galaxies can be a strong source of feedback to quench
star-formation and generate outflows. At the same time, these IMBHs form the
missing link between stellar-mass and supermassive BHs.
