The fingerprint of binary intermediate-mass black holes in globular clusters: suprathermal stars and angular momentum alignment

AbstractThe study of intermediate-mass black holes (IMBHs) is a young and promising field of research. If IMBH exist, they could explain the rapid growth of supermassive black holes by acting as seeds in the early stage of galaxy formation. Formed by runaway collisions of massive stars in young and dense stellar clusters, intermediate-mass black holes could still be present in the centers of globular clusters, today. We measured the inner kinematic profiles with integral-field spectroscopy for 10 Galactic globular cluster and determined masses or upper limits of central black holes. In combination with literature data we further studied the positions of our results on known black-hole scaling relations (such as M• − σ) and found a similar but flatter correlation for IMBHs. Applying cluster evolution codes, the change in the slope could be explained with the stellar mass loss occurring in clusters in a tidal field over its life time. Furthermore, we present results from several numerical simulations on the topic of IMBHs and integral field units (IFUs). N-body simulations were used to simulate IFU data cubes. For the specific case of NGC 6388 we simulated two different IFU techniques and found that velocity dispersion measurements from individual velocities are strongly biased towards lower values due to blends of neighbouring stars and background light. In addition, we use the Astrophysical Multipurpose Software Environment (AMUSE) to combine gravitational physics, stellar evolution and hydrodynamics to simulate the accretion of stellar winds onto a black hole. We find that the S-stars need to provide very strong winds in order to explain the accretion rate in the galactic center.

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Radio observations of NGC 2808 and other globular clusters: constraints on intermediate-mass black holes

Monthly Notices of the Royal Astronomical Society ◽

10.1111/j.1365-2966.2008.13577.x ◽

2008 ◽

Vol 389 (1) ◽

pp. 379-384 ◽

Cited By ~ 43

Author(s):

Thomas J. Maccarone ◽

Mathieu Servillat

Keyword(s):

Black Holes ◽

Globular Clusters ◽

Radio Observations ◽

Intermediate Mass ◽

Intermediate Mass Black Holes

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GLOBULAR CLUSTERS HOSTING INTERMEDIATE-MASS BLACK HOLES: NO MASS-SEGREGATION BASED CANDIDATES

The Astrophysical Journal ◽

10.3847/0004-637x/823/2/135 ◽

2016 ◽

Vol 823 (2) ◽

pp. 135 ◽

Cited By ~ 6

Author(s):

Mario Pasquato ◽

Paolo Miocchi ◽

Sohn Bong Won ◽

Young-Wook Lee

Keyword(s):

Black Holes ◽

Globular Clusters ◽

Intermediate Mass ◽

Mass Segregation ◽

Intermediate Mass Black Holes

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Synthetic extinction maps around intermediate-mass black holes in Galactic globular clusters

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stw1095 ◽

2016 ◽

Vol 460 (3) ◽

pp. 2542-2551 ◽

Cited By ~ 2

Author(s):

C. Pepe ◽

L. J. Pellizza

Keyword(s):

Black Holes ◽

Globular Clusters ◽

Intermediate Mass ◽

Galactic Globular Clusters ◽

Intermediate Mass Black Holes

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Observational evidence for intermediate-mass black holes

International Journal of Modern Physics D ◽

10.1142/s021827181730021x ◽

2017 ◽

Vol 26 (11) ◽

pp. 1730021 ◽

Cited By ~ 84

Author(s):

Mar Mezcua

Keyword(s):

Black Holes ◽

Galaxy Formation ◽

Globular Clusters ◽

High Redshift ◽

Galactic Nuclei ◽

Observational Evidence ◽

Intermediate Mass ◽

X Ray ◽

Mass Scaling ◽

Intermediate Mass Black Holes

Intermediate-mass black holes (IMBHs), with masses in the range [Formula: see text]–[Formula: see text][Formula: see text]M[Formula: see text], are the link between stellar-mass BHs and supermassive BHs (SMBHs). They are thought to be the seeds from which SMBHs grow, which would explain the existence of quasars with BH masses of up to 10[Formula: see text][Formula: see text]M[Formula: see text] when the Universe was only 0.8 Gyr old. The detection and study of IMBHs has thus strong implications for understanding how SMBHs form and grow, which is ultimately linked to galaxy formation and growth, as well as for studies of the universality of BH accretion or the epoch of reionization. Proving the existence of seed BHs in the early Universe is not yet feasible with the current instrumentation; however, those seeds that did not grow into SMBHs can be found as IMBHs in the nearby Universe. In this review, I summarize the different scenarios proposed for the formation of IMBHs and gather all the observational evidence for the few hundreds of nearby IMBH candidates found in dwarf galaxies, globular clusters, and ultraluminous X-ray sources, as well as the possible discovery of a few seed BHs at high redshift. I discuss some of their properties, such as X-ray weakness and location in the BH mass scaling relations, and the possibility to discover IMBHs through high velocity clouds, tidal disruption events, gravitational waves, or accretion disks in active galactic nuclei. I finalize with the prospects for the detection of IMBHs with up-coming observatories.

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