Diffusion of supermassive black holes in galactic nuclei

1
Diffusion of supermassive black holes in galactic
nuclei
Artem S. Kondratyev, Victor V. Orlov
Sobolev Astronomical Institute, St. Petersburg
State University, St. Petersburg, Russia
We study the migration of central black holes in
galactic nuclei due to the encounters with
globular clusters of the galaxy. The motion of
the black hole takes place in the field of the
fixed galactic bulge potential. We have found the
black hole drift's amplitude and velocity
dependences on the globular cluster's orbital
parameters, its mass, and bulge parameters. For
the Milky Way Galaxy, the drift amplitude can
reach a few tens of parsecs, while for the late
type (Sc and Sd) spiral galaxies, this amplitude
can reach more than one hundred parsecs.
We consider the galaxies with following
parameters
Rosette-like orbit of cluster
Tube-like orbit of cluster
Typical orbit of black hole
Average amplitudes ? of walking of black hole
with respect to galactic center
Initial values of parameters impact distance p
varies from 5 pc to 100 pc with a step equal to 5
pc velocity is 200 km/s initial separation from
center of galaxy to the cluster is 1 kpc.
Dependence of drift amplitude ? on impact
distance p for Milky Way model (mass of cluster
is 106 M? )
CONCLUSIONS Interactions of central
supermassive black holes (BH) in the galaxies
with encountering massive objects (e.g., globular
clusters, GMCs, etc.) may lead to the drift of
the BH. We have estimated the amplitudes of this
drift in dependence of parameters of bulge,
masses of BH and globular cluster, velocity of
fly-by). For the Milky Way model, the amplitude
of the BHs drift is about 40 pc. The amplitude
of drift does not strongly depend on the
morphological type of galaxy. Its mean value may
reach about 100 pc.
FUTURE STUDIES 1) Dynamics of binary black hole
in the central parts of galaxy 2) Consideration
of a set of bulge parameters (various types of
the galaxies) 3) Interactions of central BH with
cores of sinking dwarf galaxies.
The colors of the lines correspond to the
following velocities of cluster ? 100
km/s ? 200 km/s ? 300 km/s
? 500 km/s