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Title: The origins of off-centre massive black holes in dwarf galaxies
ABSTRACT Massive black holes often exist within dwarf galaxies, and both simulations and observations have shown that a substantial fraction of these may be off-centre with respect to their hosts. We trace the evolution of off-centre massive black holes (MBHs) in dwarf galaxies using cosmological hydrodynamical simulations, and show that the reason for off-centre locations is mainly due to galaxy–galaxy mergers. We calculate dynamical time-scales and show that off-centre MBHs are unlikely to sink to their galaxys’ centres within a Hubble time, due to the shape of the hosts’ potential wells and low stellar densities. These wandering MBHs are unlikely to be detected electromagnetically, nor is there a measurable dynamical effect on the galaxy’s stellar population. We conclude that off-centre MBHs may be common in dwarfs, especially if the mass of the MBH is small or the stellar mass of the host galaxy is large. However, detecting them is extremely challenging, because their accretion luminosities are very low and they do not measurably alter the dynamics of their host galaxies.
Authors:
; ; ; ; ; ; ; ; ; ; ;
Award ID(s):
1813961 1812642
Publication Date:
NSF-PAR ID:
10283508
Journal Name:
Monthly Notices of the Royal Astronomical Society
Volume:
505
Issue:
4
Page Range or eLocation-ID:
5129 to 5141
ISSN:
0035-8711
Sponsoring Org:
National Science Foundation
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