TY - JOUR
T1 - Sowing the seeds of massive black holes in small galaxies
T2 - Young clusters as the building blocks of ultracompact dwarf galaxies
AU - Amaro-Seoane, Pau
AU - Konstantinidis, Symeon
AU - Freitag, Marc Dewi
AU - Coleman Miller, M.
AU - Rasio, Frederic A.
N1 - Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2014/2/20
Y1 - 2014/2/20
N2 - Interacting galaxies often have complexes of hundreds of young stellar clusters of individual masses 104-106 M in regions that are a few hundred parsecs across. These cluster complexes interact dynamically, and their coalescence is a candidate for the origin of some ultracompact dwarf galaxies. Individual clusters with short relaxation times are candidates for the production of intermediate-mass black holes of a few hundred solar masses, via runaway stellar collisions prior to the first supernovae in a cluster. It is therefore possible that a cluster complex hosts multiple intermediate-mass black holes that may be ejected from their individual clusters due to mergers or binary processes, but bound to the complex as a whole. Here we explore the dynamical interaction between initially free-flying massive black holes and clusters in an evolving cluster complex. We find that, after hitting some clusters, it is plausible that the massive black hole will be captured in an ultracompact dwarf forming near the center of the complex. In the process, the hole typically triggers electromagnetic flares via stellar disruptions, and is also likely to be a prominent source of gravitational radiation for the advanced ground-based detectors LIGO and VIRGO. We also discuss other implications of this scenario, notably that the central black hole could be considerably larger than expected in other formation scenarios for ultracompact dwarfs.
AB - Interacting galaxies often have complexes of hundreds of young stellar clusters of individual masses 104-106 M in regions that are a few hundred parsecs across. These cluster complexes interact dynamically, and their coalescence is a candidate for the origin of some ultracompact dwarf galaxies. Individual clusters with short relaxation times are candidates for the production of intermediate-mass black holes of a few hundred solar masses, via runaway stellar collisions prior to the first supernovae in a cluster. It is therefore possible that a cluster complex hosts multiple intermediate-mass black holes that may be ejected from their individual clusters due to mergers or binary processes, but bound to the complex as a whole. Here we explore the dynamical interaction between initially free-flying massive black holes and clusters in an evolving cluster complex. We find that, after hitting some clusters, it is plausible that the massive black hole will be captured in an ultracompact dwarf forming near the center of the complex. In the process, the hole typically triggers electromagnetic flares via stellar disruptions, and is also likely to be a prominent source of gravitational radiation for the advanced ground-based detectors LIGO and VIRGO. We also discuss other implications of this scenario, notably that the central black hole could be considerably larger than expected in other formation scenarios for ultracompact dwarfs.
KW - Galaxies: kinematics and dynamics
KW - Galaxies: star clusters: general
KW - Gravitational waves
KW - Quasars: supermassive black holes
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U2 - 10.1088/0004-637X/782/2/97
DO - 10.1088/0004-637X/782/2/97
M3 - Article
AN - SCOPUS:84893523043
VL - 782
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 97
ER -