scholarly journals Formation and Evolution of Massive Black Holes in Star Clusters

2005 ◽  
Vol 13 ◽  
pp. 350-353
Author(s):  
Holger Baumgardt ◽  
Junichiro Makino ◽  
Simon Portegies Zwart
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Initial Conditions ◽  
Star Clusters ◽  
Dynamical Evolution ◽  
Young Star ◽  
Cluster Center ◽  
Massive Black Hole ◽  
Massive Black Holes ◽  
Equilibrium Profile

AbstractWe present results of N-body simulations on the formation of massive black holes by run-away merging in young star clusters and the later dynamical evolution of star clusters containing massive black holes. We determine the initial conditions necessary for run-away merging to form a massive black hole and study the equilibrium profile that is established in the cluster center as a result of the interaction of stars with the central black hole. Our results show that star clusters which contain black holes have projected luminosity profiles that can be fitted by standard King models. The presence of massive black holes in (post-)core collapse clusters is therefore ruled out by our simulations.

scholarly journals Tidal disruption events on to stellar black holes in triples

2019 ◽  
Vol 489 (1) ◽  
pp. 727-737 ◽  
Author(s):  
Giacomo Fragione ◽  
Nathan W C Leigh ◽  
Rosalba Perna ◽  
Bence Kocsis
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Force ◽  
Main Sequence ◽  
Initial Conditions ◽  
Main Sequence Stars ◽  
Tidal Disruption ◽  
Mean Velocity ◽  
Massive Black Holes ◽  
The Mean

ABSTRACT Stars passing too close to a black hole can produce tidal disruption events (TDEs), when the tidal force across the star exceeds the gravitational force that binds it. TDEs have usually been discussed in relation to massive black holes that reside in the centres of galaxies or lurk in star clusters. We investigate the possibility that triple stars hosting a stellar black hole (SBH) may be sources of TDEs. We start from a triple system made up of three main-sequence stars and model the supernova (SN) kick event that led to the production of an inner binary comprised of an SBH. We evolve these triples with a high-precision N-body code and study their TDEs as a result of Kozai–Lidov oscillations. We explore a variety of distributions of natal kicks imparted during the SN event, various maximum initial separations for the triples, and different distributions of eccentricities. We show that the main parameter that governs the properties of the SBH–MS binaries that produce a TDE in triples is the mean velocity of the natal kick distribution. Smaller σ’s lead to larger inner and outer semimajor axes of the systems that undergo a TDE, smaller SBH masses, and longer time-scales. We find that the fraction of systems that produce a TDE is roughly independent of the initial conditions, while estimate a TDE rate of $2.1\times 10^{-4}{\!-\!}4.7 \, \mathrm{yr}^{-1}$, depending on the prescriptions for the SBH natal kicks. This rate is almost comparable to the expected TDE rate for massive black holes.

scholarly journals 9.8. Bars and black holes

1998 ◽  
Vol 184 ◽  
pp. 397-398
Author(s):  
Eric Emsellem
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galaxies ◽  
Significant Fraction ◽  
Massive Black Hole ◽  
Central Mass ◽  
Massive Black Holes ◽  
Dark Object ◽  
Nearby Galaxies ◽  
Gas Accretion

Massive black holes are now thought to be present at the centre of a fair fraction of nearby galaxies. The origin of these central dark masses is still unknown, although tentative explanations have been proposed in an attempt to reconcile non-active galaxies with AGNs and quasars. The activity of a galaxy may then mostly depend on the efficiency of gas accretion onto the central dark object. It is important to note that many of the galaxies which are today candidates for the presence of a massive black hole are spirals. In this context, bars should play an important role in the evolution (and formation?) of a central mass, since (1) they are present in a significant fraction of spirals, (2) they may be efficient drivers of gas accretion. If indeed most of present day galaxies hosts a central dark mass, then bars and black holes should coexist in a significant fraction of them. We examine here the cases of 3 edge-on galaxies which are candidates for the presence of a central black holes: NGC 4570, NGC 3115 and M 104.

scholarly journals Probing Massive Black Hole Binary Populations with LISA

2019 ◽  
Author(s):  
Michael L Katz ◽  
Luke Zoltan Kelley ◽  
Fani Dosopoulou ◽  
Samantha Berry ◽  
Laura Blecha ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Evolutionary Process ◽  
Massive Black Hole ◽  
Detection Rates ◽  
Massive Black Holes ◽  
Affect Detection ◽  
Lower Detection ◽  
Black Hole Binary

Abstract ESA and NASA are moving forward with plans to launch LISA around 2034. With data from the Illustris cosmological simulation, we provide analysis of LISA detection rates accompanied by characterization of the merging massive black hole population. Massive black holes of total mass ∼105 − 1010M⊙ are the focus of this study. We evolve Illustris massive black hole mergers, which form at separations on the order of the simulation resolution (∼kpc scales), through coalescence with two different treatments for the binary massive black hole evolutionary process. The coalescence times of the population, as well as physical properties of the black holes, form a statistical basis for each evolutionary treatment. From these bases, we Monte Carlo synthesize many realizations of the merging massive black hole population to build mock LISA detection catalogs. We analyze how our massive black hole binary evolutionary models affect detection rates and the associated parameter distributions measured by LISA. With our models, we find massive black hole binary detection rates with LISA of ∼0.5 − 1 yr−1 for massive black holes with masses greater than 105M⊙. This should be treated as a lower limit primarily because our massive black hole sample does not include masses below 105M⊙, which may significantly add to the observed rate. We suggest reasons why we predict lower detection rates compared to much of the literature.

scholarly journals Tidal disruption events from massive black hole binaries: predictions for ongoing and future surveys

2019 ◽  
Vol 488 (3) ◽  
pp. 4042-4060 ◽  
Author(s):  
Stephen Thorp ◽  
Eli Chadwick ◽  
Alberto Sesana
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Low Frequency ◽  
Mass Range ◽  
Tidal Disruption ◽  
Massive Black Hole ◽  
Massive Black Holes ◽  
X Ray ◽  
Black Hole Binaries ◽  
Survey Instruments

ABSTRACT We compute the expected cosmic rates of tidal disruption events (TDEs) induced by individual massive black holes (MBHs) and by MBH binaries (MBHBs) – with a specific focus on the latter class – to explore the potential of TDEs to probe the cosmic population of sub-pc MBHBs. Rates are computed by combining MBH and MBHB population models derived from large cosmological simulations with estimates of the induced TDE rates for each class of objects. We construct empirical TDE spectra that fit a large number of observations in the optical, UV, and X-ray and consider their observability by current and future survey instruments. Consistent with results in the literature, and depending on the detailed assumption of the model, we find that LSST and Gaia in optical and eROSITA in X-ray will observe a total of 3000–6000, 80–180, and 600–900 TDEs per year, respectively. Depending on the survey, 1 to several per cent of these are prompted by MBHBs. In particular, both LSST and eROSITA are expected to see 150–450 MBHB-induced TDEs in their respective mission lifetimes, including 5–100 repeated flares. The latter provide an observational sample of binary candidates with relatively low contamination and have the potential of unveiling the sub-pc population of MBHBs in the mass range $10^5\lt M\lt 10^7\, \mathrm{M}_\odot$, thus informing future low-frequency gravitational wave observatories.

scholarly journals Tidal disruption events from different kinds of astrophysical objects: a preliminary analysis

2016 ◽  
Vol 12 (S324) ◽  
pp. 132-133
Author(s):  
Aurora Clerici ◽  
Andreja Gomboc
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Preliminary Analysis ◽  
Tidal Disruption ◽  
Massive Black Hole ◽  
Massive Black Holes ◽  
Astrophysical Objects

AbstractTidal disruption events are a powerful tool to study quiescent massive black holes residing in the centre of galaxies. Occasionally, astrophysical objects such as stars, planets and smaller bodies are captured and tidally disrupted by the massive black hole, giving rise to a luminous flare. A detailed study of disruption parameters and the emitted radiation can give important insights on the black hole and its surroundings.

scholarly journals Black hole and nuclear cluster scaling relations: Mbh ∝ Mnc2.7±0.7

2014 ◽  
Vol 10 (S312) ◽  
pp. 269-273 ◽  
Author(s):  
Alister W. Graham
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Star Clusters ◽  
Compact Object ◽  
Scaling Relations ◽  
Black Hole Mass ◽  
Massive Black Holes ◽  
Mass Scaling ◽  
Nuclear Cluster ◽  
Evolutionary Growth

AbstractThere is a growing array of supermassive black hole and nuclear star cluster scaling relations with their host spheroid, including a bent (black hole mass)–(host spheroid mass) Mbh–Msph relation and a different (massive compact object mass)–(host spheroid velocity dispersion) Mmco–σ relations for black holes and nuclear star clusters. By combining the observed Mbh ∝ σ5.5 relation with the observed Mnc ∝ σ1.6–2.7 relation, we derive the expression Mbh ∝ Mnc2–3.4, which should hold until the nuclear star clusters are eventually destroyed in the larger core-Sérsic spheroids. This new mass scaling relation helps better quantify the rapid evolutionary growth of massive black holes in dense star clusters, and the relation is consistently recovered when coupling the observed Mnc ∝ Msph0.6–1.0 relation with the recently observed quadratic relation Mbh ∝ Msph2 for Sérsic spheroids.

scholarly journals The Early Evolution of Massive Black Holes

2009 ◽  
Vol 5 (S267) ◽  
pp. 26-33 ◽  
Author(s):  
Marta Volonteri
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Velocity Dispersion ◽  
Host Galaxy ◽  
Formation Processes ◽  
Hole Formation ◽  
Physical Processes ◽  
Massive Black Hole ◽  
Potential Wells ◽  
Massive Black Holes

AbstractMassive black holes (MBHs) are nowadays believed to reside in most local galaxies. Studies have also established a number of relations between the MBH mass and properties of the host galaxy such as bulge mass and velocity dispersion. These results suggest that central MBHs, while much less massive than their hosts (~ 0.1%), are linked to the evolution of galactic structure. When did it all start? In hierarchical cosmologies, a single big galaxy today can be traced back to the stage when it was split up in hundreds of smaller components. Did MBH seeds form with the same efficiency in small proto-galaxies, or did their formation have to await the buildup of substantial galaxies with deeper potential wells? I briefly review here some of the physical processes that are conducive to the evolution of the massive black hole population. I will discuss black hole formation processes for “seed” black holes that are likely to take place at early cosmic epochs, and possible observational tests of these scenarios.

scholarly journals Planetary systems in a star cluster II: intermediate-mass black holes and planetary systems

2020 ◽  
Vol 497 (3) ◽  
pp. 3623-3637
Author(s):  
Francesco Flammini Dotti ◽  
M B N Kouwenhoven ◽  
Qi Shu ◽  
Wei Hao ◽  
Rainer Spurzem
Keyword(s):  
Black Holes ◽  
Star Clusters ◽  
Planetary Systems ◽  
Dynamical Evolution ◽  
Star Cluster ◽  
High Mass ◽  
Intermediate Mass ◽  
Massive Black Holes ◽  
Mass Segregation ◽  
Intermediate Mass Black Holes

ABSTRACT Most stars form in dense stellar environments. It is speculated that some dense star clusters may host intermediate-mass black holes (IMBHs), which may have formed from runaway collisions between high-mass stars, or from the mergers of less massive black holes. Here, we numerically explore the evolution of populations of planets in star clusters with an IMBH. We study the dynamical evolution of single-planet systems and free-floating planets, over a period of 100 Myr, in star clusters without an IMBH, and in clusters with a central IMBH of mass $100\, \mathrm{M}_\odot$ or $200\, \mathrm{M}_\odot$. In the central region ($r\lesssim 0.2$ pc), the IMBH’s tidal influence on planetary systems is typically 10 times stronger than the average neighbour star. For a star cluster with a $200\, \mathrm{M}_\odot$ IMBH, the region in which the IMBH’s influence is stronger within the virial radius (∼1 pc). The IMBH quenches mass segregation, and the stars in the core tend to move towards intermediate regions. The ejection rate of both stars and planets is higher when an IMBH is present. The rate at which planets are expelled from their host star rate is higher for clusters with higher IMBH masses, for t < 0.5trh, while remains mostly constant while the star cluster fills its Roche lobe, similar to a star cluster without an IMBH. The disruption rate of planetary systems is higher in initially denser clusters, and for wider planetary orbits, but this rate is substantially enhanced by the presence of a central IMBH.

scholarly journals A loud quasi-periodic oscillation after a star is disrupted by a massive black hole

Science ◽  
2019 ◽  
Vol 363 (6426) ◽  
pp. 531-534 ◽  
Author(s):  
Dheeraj R. Pasham ◽  
Ronald A. Remillard ◽  
P. Chris Fragile ◽  
Alessia Franchini ◽  
Nicholas C. Stone ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Periodic Oscillation ◽  
Host Galaxy ◽  
X Rays ◽  
Tidal Disruption ◽  
Massive Black Hole ◽  
Quasi Periodic Oscillation ◽  
Massive Black Holes ◽  
Tidal Forces

The tidal forces close to massive black holes can rip apart stars that come too close to them. As the resulting stellar debris spirals toward the black hole, the debris heats up and emits x-rays. We report observations of a stable 131-second x-ray quasi-periodic oscillation from the tidal disruption event ASASSN-14li. Assuming the black hole mass indicated by host galaxy scaling relations, these observations imply that the periodicity originates from close to the event horizon and that the black hole is rapidly spinning. Our findings demonstrate that tidal disruption events can generate quasi-periodic oscillations that encode information about the physical properties of their black holes.

Is there a massive black hole at the galactic center?

1979 ◽  
Vol 84 ◽  
pp. 395-400
Author(s):  
L. M. Ozernoy
Keyword(s):  
Black Hole ◽  
Galactic Center ◽  
Dynamical Evolution ◽  
Galactic Nuclei ◽  
Black Hole Mass ◽  
Massive Black Hole ◽  
Massive Black Holes ◽  
Infrared Observations ◽  
The Galaxy ◽  
Remote Past

During the past 10 years an hypothesis about the presence of a massive black hole at the center of our Galaxy (Lynden-Bell, 1969) has been an object of many exciting speculations. This hypothesis is based, firstly, on attempts to explain the nature of the “point radio source” at the galactic center (as well as a presumed much more powerful activity of the galactic nucleus in the remote past), and, secondly, on the opinion that the conditions in the course of dynamical evolution of galactic nuclei are favorable for the formation of massive black holes. However, both these approaches did not succeed in predicting with any confidence the black hole mass at the center of the Galaxy. The estimates available are based on indirect arguments and range from 107-1011 M⊙ (Novikov and Thorne, 1973) to 104 M⊙ (Shklovskii, 1976). A recent dynamical approach using NeII infrared observations of the galactic center (Wollman et al., 1977) has indicated that the black hole mass does not exceed 5×106 M⊙ (Oort, 1977), although this value may well be due to a very dense star cluster whose brightest members only are seen in the infrared.

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