scholarly journals Black Holes in Galactic Nuclei, X-Ray Binaries and Ultraluminous X-Ray Sources

2005 ◽  
Vol 22 (3) ◽  
pp. 195-198 ◽  
Author(s):  
Zdenka Kuncic
Keyword(s):  
Black Holes ◽  
Galactic Nuclei ◽  
Stellar Mass ◽  
Supermassive Black Holes ◽  
Intermediate Mass ◽  
X Ray ◽  
Gravitational Influence ◽  
X Ray Binaries ◽  
Intermediate Mass Black Holes

AbstractThis review summarizes the astrophysical evidence for the existence of black holes provided by their gravitational influence on nearby matter. Two classes of accreting black holes have now been observationally verified: supermassive black holes (SMBHs) in galactic nuclei, and stellar-mass black holes in X-ray binaries (XRBs). With the recent re-discovery of ultra-luminous X-ray (ULX) sources, fresh evidence has also emerged for the existence of a third class of accreting black holes: intermediate-mass black holes (IMBHs). The properties of the three classes of accreting black holes are briefly discussed.

scholarly journals Black holes: from stars to galaxies

2006 ◽  
Vol 2 (S238) ◽  
pp. 309-314 ◽  
Author(s):  
I. Félix Mirabel
Keyword(s):  
Black Holes ◽  
Binary Systems ◽  
Stellar Mass ◽  
Supermassive Black Holes ◽  
Intermediate Mass ◽  
X Ray ◽  
Nearby Galaxies ◽  
Intermediate Mass Black Holes

AbstractWhile until recently they were often considered as exotic objects of dubious existence, in the last decades there have been overwhelming observational evidences for the presence of stellar mass black holes in binary systems, supermassive black holes at the centers of galaxies, and possibly, intermediate-mass black holes observed as ultraluminous X-ray sources in nearby galaxies. Black holes are now widely accepted as real physical entities that play an important role in several areas of modern astrophysics.Here I review the concluding remarks of the IAU Symposium No 238 on Black Holes, with particular emphasis on the topical questions in this area of research.

scholarly journals Formation of supermassive black holes in galactic nuclei – I. Delivering seed intermediate-mass black holes in massive stellar clusters

2021 ◽  
Vol 502 (2) ◽  
pp. 2682-2700
Author(s):  
Abbas Askar ◽  
Melvyn B Davies ◽  
Ross P Church
Keyword(s):  
Black Holes ◽  
Galactic Nuclei ◽  
Supermassive Black Holes ◽  
Stellar Clusters ◽  
Orbital Eccentricity ◽  
Intermediate Mass ◽  
Stellar Cluster ◽  
Wave Emission ◽  
Gas Accretion ◽  
Intermediate Mass Black Holes

ABSTRACT Supermassive black holes (SMBHs) are found in most galactic nuclei. A significant fraction of these nuclei also contains a nuclear stellar cluster (NSC) surrounding the SMBH. In this paper, we consider the idea that the NSC forms first, from the merger of several stellar clusters that may contain intermediate-mass black holes (IMBHs). These IMBHs can subsequently grow in the NSC and form an SMBH. We carry out N-body simulations of the simultaneous merger of three stellar clusters to form an NSC, and investigate the outcome of simulated runs containing zero, one, two, and three IMBHs. We find that IMBHs can efficiently sink to the centre of the merged cluster. If multiple merging clusters contain an IMBH, we find that an IMBH binary is likely to form and subsequently merge by gravitational wave emission. We show that these mergers are catalyzed by dynamical interactions with surrounding stars, which systematically harden the binary and increase its orbital eccentricity. The seed SMBH will be ejected from the NSC by the recoil kick produced when two IMBHs merge, if their mass ratio q ≳ 0.15. If the seed is ejected then no SMBH will form in the NSC. This is a natural pathway to explain those galactic nuclei that contain an NSC but apparently lack an SMBH, such as M33. However, if an IMBH is retained then it can seed the growth of an SMBH through gas accretion and tidal disruption of stars.

scholarly journals Observational evidence for intermediate-mass black holes

2017 ◽  
Vol 26 (11) ◽  
pp. 1730021 ◽  
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.

scholarly journals X‐Ray Emission from Active Galactic Nuclei with Intermediate‐Mass Black Holes

2008 ◽  
Vol 689 (2) ◽  
pp. 762-774 ◽  
Author(s):  
G. C. Dewangan ◽  
S. Mathur ◽  
R. E. Griffiths ◽  
A. R. Rao
Keyword(s):  
Black Holes ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Intermediate Mass ◽  
X Ray ◽  
Intermediate Mass Black Holes

Do Intermediate-Mass Black Holes Exist?

2014 ◽  
Author(s):  
Charles D. Bailyn
Keyword(s):  
Black Holes ◽  
Empirical Evidence ◽  
Stellar Mass ◽  
Supermassive Black Holes ◽  
The Sun ◽  
Intermediate Mass ◽  
Lines Of Evidence ◽  
Intermediate Mass Black Holes

This chapter addresses the existence of intermediate-mass black holes. There is powerful empirical evidence for two classes of black holes, namely, the stellar-mass black holes, with masses a few times that of the Sun, and the supermassive black holes at the centers of galaxies. The considerable gap in mass between these two categories naturally prompts the question whether black holes might exist at other mass scales. In recent years, two lines of evidence have been presented in support of the idea that black holes with masses intermediate between stellar mass and supermassive might exist. Such sources are referred to as intermediate-mass black holes. In both cases the results are currently still ambiguous, and much debated.

scholarly journals A NEW SAMPLE OF CANDIDATE INTERMEDIATE-MASS BLACK HOLES SELECTED BY X-RAY VARIABILITY

2012 ◽  
Vol 751 (1) ◽  
pp. 39 ◽  
Author(s):  
Naoya Kamizasa ◽  
Yuichi Terashima ◽  
Hisamitsu Awaki
Keyword(s):  
Black Holes ◽  
Intermediate Mass ◽  
X Ray ◽  
Intermediate Mass Black Holes

scholarly journals Probing black hole accretion tracks, scaling relations, and radiative efficiencies from stacked X-ray active galactic nuclei

2019 ◽  
Vol 493 (1) ◽  
pp. 1500-1511 ◽  
Author(s):  
Francesco Shankar ◽  
David H Weinberg ◽  
Christopher Marsden ◽  
Philip J Grylls ◽  
Mariangela Bernardi ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Selection Bias ◽  
Stellar Mass ◽  
Supermassive Black Holes ◽  
Independent Evidence ◽  
X Ray ◽  
Black Hole Accretion ◽  
Black Hole Masses ◽  
Hole Accretion

ABSTRACT The masses of supermassive black holes at the centres of local galaxies appear to be tightly correlated with the mass and velocity dispersions of their galactic hosts. However, the local Mbh–Mstar relation inferred from dynamically measured inactive black holes is up to an order-of-magnitude higher than some estimates from active black holes, and recent work suggests that this discrepancy arises from selection bias on the sample of dynamical black hole mass measurements. In this work, we combine X-ray measurements of the mean black hole accretion luminosity as a function of stellar mass and redshift with empirical models of galaxy stellar mass growth, integrating over time to predict the evolving Mbh–Mstar relation. The implied relation is nearly independent of redshift, indicating that stellar and black hole masses grow, on average, at similar rates. Matching the de-biased local Mbh–Mstar relation requires a mean radiative efficiency ε ≳ 0.15, in line with theoretical expectations for accretion on to spinning black holes. However, matching the ‘raw’ observed relation for inactive black holes requires ε ∼ 0.02, far below theoretical expectations. This result provides independent evidence for selection bias in dynamically estimated black hole masses, a conclusion that is robust to uncertainties in bolometric corrections, obscured active black hole fractions, and kinetic accretion efficiency. For our fiducial assumptions, they favour moderate-to-rapid spins of typical supermassive black holes, to achieve ε ∼ 0.12–0.20. Our approach has similarities to the classic Soltan analysis, but by using galaxy-based data instead of integrated quantities we are able to focus on regimes where observational uncertainties are minimized.

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