scholarly journals THE ROLE OF NUCLEAR STAR CLUSTERS IN ENHANCING SUPERMASSIVE BLACK HOLE FEEDING RATES DURING GALAXY MERGERS

2015 ◽  
Vol 803 (2) ◽  
pp. 81 ◽  
Author(s):  
J. P. Naiman ◽  
E. Ramirez-Ruiz ◽  
J. Debuhr ◽  
C.-P. Ma
Keyword(s):  
Black Hole ◽  
Star Clusters ◽  
Galaxy Mergers ◽  
Feeding Rates ◽  
Supermassive Black Hole

scholarly journals Morphological evolution of supermassive black hole merger hosts and multimessenger signatures

2021 ◽  
Vol 503 (3) ◽  
pp. 3629-3642
Author(s):  
Colin DeGraf ◽  
Debora Sijacki ◽  
Tiziana Di Matteo ◽  
Kelly Holley-Bockelmann ◽  
Greg Snyder ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Star Formation ◽  
Morphological Evolution ◽  
Full Range ◽  
High Mass ◽  
Morphological Evidence ◽  
Galaxy Mergers ◽  
Host Galaxies ◽  
Supermassive Black Hole

ABSTRACT With projects such as Laser Interferometer Space Antenna (LISA) and Pulsar Timing Arrays (PTAs) expected to detect gravitational waves from supermassive black hole mergers in the near future, it is key that we understand what we expect those detections to be, and maximize what we can learn from them. To address this, we study the mergers of supermassive black holes in the Illustris simulation, the overall rate of mergers, and the correlation between merging black holes and their host galaxies. We find these mergers occur in typical galaxies along the MBH−M* relation, and that between LISA and PTAs we expect to probe the full range of galaxy masses. As galaxy mergers can trigger star formation, we find that galaxies hosting low-mass black hole mergers tend to show a slight increase in star formation rates compared to a mass-matched sample. However, high-mass merger hosts have typical star formation rates, due to a combination of low gas fractions and powerful active galactic nucleus feedback. Although minor black hole mergers do not correlate with disturbed morphologies, major mergers (especially at high-masses) tend to show morphological evidence of recent galaxy mergers which survive for ∼500 Myr. This is on the same scale as the infall/hardening time of merging black holes, suggesting that electromagnetic follow-ups to gravitational wave signals may not be able to observe this correlation. We further find that incorporating a realistic time-scale delay for the black hole mergers could shift the merger distribution towards higher masses, decreasing the rate of LISA detections while increasing the rate of PTA detections.

scholarly journals Black hole and neutron star mergers in galactic nuclei: the role of triples

2019 ◽  
Vol 488 (2) ◽  
pp. 2825-2835 ◽  
Author(s):  
Giacomo Fragione ◽  
Nathan W C Leigh ◽  
Rosalba Perna
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Neutron Star ◽  
Massive Stars ◽  
Star Clusters ◽  
Galactic Nuclei ◽  
Compact Objects ◽  
Large Numbers ◽  
Binary Case

ABSTRACT Nuclear star clusters that surround supermassive black holes (SMBHs) in galactic nuclei are thought to contain large numbers of black holes (BHs) and neutron stars (NSs), a fraction of which form binaries and could merge by Kozai–Lidov oscillations (KL). Triple compact objects are likely to be present, given what is known about the multiplicity of massive stars, whose life ends either as an NS or a BH. In this paper, we present a new possible scenario for merging BHs and NSs in galactic nuclei. We study the evolution of a triple black hole (BH) or neutron star (NS) system orbiting an SMBH in a galactic nucleus by means of direct high-precision N-body simulations, including post-Newtonian terms. We find that the four-body dynamical interactions can increase the KL angle window for mergers compared to the binary case and make BH and NS binaries merge on shorter time-scales. We show that the merger fraction can be up to ∼5–8 times higher for triples than for binaries. Therefore, even if the triple fraction is only ∼10–$20\rm{\,per\,cent}$ of the binary fraction, they could contribute to the merger events observed by LIGO/VIRGO in comparable numbers.

scholarly journals Tidal disruption as a probe for supermassive black hole binaries

2014 ◽  
Vol 10 (S312) ◽  
pp. 43-47
Author(s):  
Shuo Li ◽  
Fukun Liu ◽  
Peter Berczik ◽  
Rainer Spurzem
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Galactic Center ◽  
Galaxy Mergers ◽  
Tidal Disruption ◽  
Black Hole Binaries ◽  
Supermassive Black Hole ◽  
Before And After ◽  
Many Core ◽  
Disruption Event

AbstractSupermassive black hole binaries (SMBHBs) are the products of frequent galaxy mergers. It is very hard to be detected in quiescent galaxy. By using one million particle direct N-body simulations on special many-core hardware (GPU cluster), we study the dynamical co-evolution of SMBHB and its surrounding stars, specially focusing on the evolution of stellar tidal disruption event (TDE) rates before and after the coalescence of the SMBHB. We find a boosted TDE rate during the merger of the galaxies. After the coalescence of two supermassive black holes (SMBHs), the post-merger SMBH can get a kick velocity due to the anisotropic GW radiations. Our results about the recoiling SMBH, which oscillates around galactic center, show that most of TDEs are contributed by unbound stars when the SMBH passing through galactic center. In addition, the TDE light curve in SMBHB system is significantly different from the curve for single SMBH, which can be used to identify the SMBHB.

scholarly journals Galaxy Core Formation by Supermassive Black Hole Binaries: The Importance of Realistic Initial Conditions and Galaxy Morphology

2021 ◽  
Vol 922 (1) ◽  
pp. 40
Author(s):  
Fani Dosopoulou ◽  
Jenny E. Greene ◽  
Chung-Pei Ma
Keyword(s):  
Black Hole ◽  
Initial Conditions ◽  
Initial Density ◽  
Stellar Mass ◽  
Galaxy Mergers ◽  
Mass Ratio ◽  
Black Hole Binaries ◽  
Monte Carlo Techniques ◽  
Supermassive Black Hole ◽  
Order Of Magnitude

Abstract The binding energy liberated by the coalescence of supermassive black hole (SMBH) binaries during galaxy mergers is thought to be responsible for the low density cores often found in bright elliptical galaxies. We use high-resolution N-body and Monte Carlo techniques to perform single and multistage galaxy merger simulations and systematically study the dependence of the central galaxy properties on the binary mass ratio, the slope of the initial density cusps, and the number of mergers experienced. We study both the amount of depleted stellar mass (or mass deficit), M def, and the radial extent of the depleted region, r b. We find that r b ≃ r SOI and that M def varies in the range of 0.5–4M •, with r SOI the influence radius of the remnant SMBH and M • its mass. The coefficients in these relations depend weakly on the binary mass ratio and remain remarkably constant through subsequent mergers. We conclude that the core size and mass deficit do not scale linearly with the number of mergers, making it hard to infer merger histories from observations. On the other hand, we show that both M def and r b are sensitive to the morphology of the galaxy merger remnant, and that adopting spherical initial conditions, as done in early work, leads to misleading results. Our models reproduce the range of values for M def found in most observational work, but span nearly an order-of magnitude range around the true ejected stellar mass.

scholarly journals A Quasar-based Supermassive Black Hole Binary Population Model: Implications for the Gravitational Wave Background

2022 ◽  
Vol 924 (2) ◽  
pp. 93
Author(s):  
J. Andrew Casey-Clyde ◽  
Chiara M. F. Mingarelli ◽  
Jenny E. Greene ◽  
Kris Pardo ◽  
Morgan Nañez ◽  
...  
Keyword(s):  
Black Hole ◽  
Gravitational Wave ◽  
Population Model ◽  
Galaxy Mergers ◽  
Number Density ◽  
Data Set ◽  
Underlying Distribution ◽  
Supermassive Black Hole ◽  
Gravitational Wave Background ◽  
Local Number

Abstract The nanohertz gravitational wave background (GWB) is believed to be dominated by GW emission from supermassive black hole binaries (SMBHBs). Observations of several dual-active galactic nuclei (AGN) strongly suggest a link between AGN and SMBHBs, given that these dual-AGN systems will eventually form bound binary pairs. Here we develop an exploratory SMBHB population model based on empirically constrained quasar populations, allowing us to decompose the GWB amplitude into an underlying distribution of SMBH masses, SMBHB number density, and volume enclosing the GWB. Our approach also allows us to self-consistently predict the number of local SMBHB systems from the GWB amplitude. Interestingly, we find the local number density of SMBHBs implied by the common-process signal in the NANOGrav 12.5-yr data set to be roughly five times larger than previously predicted by other models. We also find that at most ∼25% of SMBHBs can be associated with quasars. Furthermore, our quasar-based approach predicts ≳95% of the GWB signal comes from z ≲ 2.5, and that SMBHBs contributing to the GWB have masses ≳108 M ⊙. We also explore how different empirical galaxy–black hole scaling relations affect the local number density of GW sources, and find that relations predicting more massive black holes decrease the local number density of SMBHBs. Overall, our results point to the important role that a measurement of the GWB will play in directly constraining the cosmic population of SMBHBs, as well as their connections to quasars and galaxy mergers.

scholarly journals Rapid Formation of Supermassive Black Hole Binaries in Galaxy Mergers with Gas

Science ◽  
2007 ◽  
Vol 316 (5833) ◽  
pp. 1874-1877 ◽  
Author(s):  
L. Mayer ◽  
S. Kazantzidis ◽  
P. Madau ◽  
M. Colpi ◽  
T. Quinn ◽  
...  
Keyword(s):  
Black Hole ◽  
Galaxy Mergers ◽  
Black Hole Binaries ◽  
Supermassive Black Hole ◽  
Rapid Formation

scholarly journals Limits on First Structure Formation from Pulsar Timing

2015 ◽  
Vol 11 (A29B) ◽  
pp. 329-335
Author(s):  
R. M. Shannon
Keyword(s):  
Black Hole ◽  
Gravitational Waves ◽  
Galaxy Mergers ◽  
Host Galaxies ◽  
Arrival Times ◽  
Black Hole Binaries ◽  
Supermassive Black Hole ◽  
Pulsar Timing ◽  
Formation And Evolution ◽  
Promising Source

AbstractBy monitoring the arrival times from millisecond pulsars for years to decades, it is possible to search for, or place limits on, nanohertz frequency gravitational radiation. The most promising source of gravitational waves in this band is a stochastic background emitted from a population of supermassive black hole binaries. As these binaries are the direct product of of galaxy mergers and the properties of the SMBHs correlated strongly with their host galaxies, the gravitational wave emission of the binaries can be used to study how galaxies evolve. Here I discuss how pulsar timing can be used to search for gravitational waves, and how limits on the strength of the background are being used to challenge models of supermassive black hole formation and evolution.

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