scholarly journals Probing Massive Black Hole Binary Populations with LISA

Author(s):  
Michael L Katz ◽  
Luke Zoltan Kelley ◽  
Fani Dosopoulou ◽  
Samantha Berry ◽  
Laura Blecha ◽  
...  

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.

2020 ◽  
Vol 497 (1) ◽  
pp. 739-746 ◽  
Author(s):  
Imran Nasim ◽  
Alessia Gualandris ◽  
Justin Read ◽  
Walter Dehnen ◽  
Maxime Delorme ◽  
...  

ABSTRACT The coalescence of massive black hole binaries (BHBs) in galactic mergers is the primary source of gravitational waves (GWs) at low frequencies. Current estimates of GW detection rates for the Laser Interferometer Space Antenna and the Pulsar Timing Array vary by three orders of magnitude. To understand this variation, we simulate the merger of equal-mass, eccentric, galaxy pairs with central massive black holes and shallow inner density cusps. We model the formation and hardening of a central BHB using the fast multiple method as a force solver, which features a O(N) scaling with the number N of particles and obtains results equivalent to direct-summation simulations. At N ∼ 5 × 105, typical for contemporary studies, the eccentricity of the BHBs can vary significantly for different random realizations of the same initial condition, resulting in a substantial variation of the merger time-scale. This scatter owes to the stochasticity of stellar encounters with the BHB and decreases with increasing N. We estimate that N ∼ 107 within the stellar half-light radius suffices to reduce the scatter in the merger time-scale to ∼10 per cent. Our results suggest that at least some of the uncertainty in low-frequency GW rates owes to insufficient numerical resolution.


1998 ◽  
Vol 184 ◽  
pp. 397-398
Author(s):  
Eric Emsellem

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.


2009 ◽  
Vol 5 (S267) ◽  
pp. 332-332
Author(s):  
Vladimír Karas ◽  
Ladislav Šubr

AbstractFluid disks and tori around black holes are discussed within different approaches and with the emphasis on the role of disk gravity. We first review the prospects for investigating the gravitational field of a black hole–disk system by analytical solutions of stationary, axially symmetric Einstein equations. More detailed considerations are focused on the middle and outer parts of extended disk-like configurations where relativistic effects are small and the Newtonian description is adequate. As an example, we investigate the case of a torus near a massive black hole that is a member of the black-hole binary system.


2019 ◽  
Vol 488 (3) ◽  
pp. 4042-4060 ◽  
Author(s):  
Stephen Thorp ◽  
Eli Chadwick ◽  
Alberto Sesana

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.


2016 ◽  
Vol 12 (S324) ◽  
pp. 132-133
Author(s):  
Aurora Clerici ◽  
Andreja Gomboc

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.


2009 ◽  
Vol 5 (S267) ◽  
pp. 26-33 ◽  
Author(s):  
Marta Volonteri

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.


2005 ◽  
Vol 13 ◽  
pp. 350-353
Author(s):  
Holger Baumgardt ◽  
Junichiro Makino ◽  
Simon Portegies Zwart

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.


Science ◽  
2019 ◽  
Vol 363 (6426) ◽  
pp. 531-534 ◽  
Author(s):  
Dheeraj R. Pasham ◽  
Ronald A. Remillard ◽  
P. Chris Fragile ◽  
Alessia Franchini ◽  
Nicholas C. Stone ◽  
...  

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.


2020 ◽  
Vol 495 (1) ◽  
pp. L12-L16 ◽  
Author(s):  
Pierre Boldrini ◽  
Roya Mohayaee ◽  
Joseph Silk

ABSTRACT Using fully GPU N-body simulations, we demonstrate for the first time that subhaloes sink and transfer energy via dynamical friction into the centres of dwarf galaxies. This dynamical heating kicks any central massive black hole out to tens of parsecs, especially at early epochs (z = 1.5–3). This mechanism helps explain the observed off-centre black holes (BHs) in dwarf galaxies and also predicts that off-centre BHs are more common in higher mass dwarf galaxies since dynamical friction becomes significantly weaker and BHs take more time to sink back towards the centres of their host galaxies. One consequence of off-centre BHs during early epochs of dwarf galaxies is to quench any BH feedback.


2020 ◽  
Vol 496 (1) ◽  
pp. 921-932
Author(s):  
Henriette Wirth ◽  
Kenji Bekki

ABSTRACT Recent observational studies of ultracompact dwarf galaxies (UCDs) have discovered the massive black hole (MBH), with masses of more than ${10^6~\rm M_\odot }$, in their central regions. We here consider that these MBHs can be formed through the merging of intermediate-mass black hole (IMBH), with masses of (103–105) M⊙, within the stellar nuclei of dwarf galaxies, which are progenitors of UCDs. We numerically investigate this formation process for a wide range of model parameters using N-body simulations. This means that IMBH growth and feedback is neglected in this study. We find that only massive IMBHs of $10^5~\rm M_\odot$ sink into the central regions of their host dwarf ($\approx 10^{10}~\rm M_\odot$) to be gravitationally trapped by its stellar nucleus within less than 1 Gyr in most dwarf models. We also find that lighter IMBHs with $(1\!-\!30) \times 10^3~\rm M_\odot$ sink into the centre in low-mass dwarfs ($\approx 10^{9}~\rm M_\odot$) due to more efficient dynamical frictionitionally, we show that the IMBHs can form binaries in the centre and, rarely, before they reach the centre, which may lead to the IMBHs merging and thus emitting gravitational waves that could be detected by LISA. Finally, we discuss the required number of IMBHs for the MBH formation in UCDs and the physical roles of stellar nuclei in IMBH binaries and mergers.


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