scholarly journals Orbital evolution of a massive black hole pair by dynamical friction

1994 ◽  
Vol 433 ◽  
pp. 733 ◽  
Author(s):  
Alberto Vecchio ◽  
Monica Colpi ◽  
Alexander G. Polnarev
2020 ◽  
Vol 498 (3) ◽  
pp. 3601-3615 ◽  
Author(s):  
Elisa Bortolas ◽  
Pedro R Capelo ◽  
Tommaso Zana ◽  
Lucio Mayer ◽  
Matteo Bonetti ◽  
...  

ABSTRACT The forthcoming Laser Interferometer Space Antenna (LISA) will probe the population of coalescing massive black hole (MBH) binaries up to the onset of structure formation. Here, we simulate the galactic-scale pairing of ∼106 M⊙ MBHs in a typical, non-clumpy main-sequence galaxy embedded in a cosmological environment at z = 7–6. In order to increase our statistical sample, we adopt a strategy that allows us to follow the evolution of six secondary MBHs concomitantly. We find that the magnitude of the dynamical-friction-induced torques is significantly smaller than that of the large-scale, stochastic gravitational torques arising from the perturbed and morphologically evolving galactic disc, suggesting that the standard dynamical friction treatment is inadequate for realistic galaxies at high redshift. The dynamical evolution of MBHs is very stochastic, and a variation in the initial orbital phase can lead to a drastically different time-scale for the inspiral. Most remarkably, the development of a galactic bar in the host system either significantly accelerates the inspiral by dragging a secondary MBH into the centre, or ultimately hinders the orbital decay by scattering the MBH in the galaxy outskirts. The latter occurs more rarely, suggesting that galactic bars overall promote MBH inspiral and binary coalescence. The orbital decay time can be an order of magnitude shorter than what would be predicted relying on dynamical friction alone. The stochasticity and the important role of global torques have crucial implications for the rates of MBH coalescences in the early Universe: both have to be accounted for when making predictions for the upcoming LISA observatory.


Author(s):  
Mohammad Sayeb ◽  
Laura Blecha ◽  
Luke Zoltan Kelley ◽  
Davide Gerosa ◽  
Michael Kesden ◽  
...  

Abstract Massive black hole (MBH) binary inspiral time scales are uncertain, and their spins are even more poorly constrained. Spin misalignment introduces asymmetry in the gravitational radiation, which imparts a recoil kick to the merged MBH. Understanding how MBH binary spins evolve is crucial for determining their recoil velocities, their gravitational wave (GW) waveforms detectable with LISA, as well as their retention rate in galaxies. Here we introduce a sub-resolution model for gas- and GW-driven MBH binary spin evolution using accreting MBHs from the Illustris cosmological hydrodynamics simulations. We also model binary inspiral via dynamical friction, stellar scattering, viscous gas drag, and GW emission. Our model assumes that the circumbinary disk always removes angular momentum from the binary. It also assumes differential accretion, which causes greater alignment of the secondary MBH spin in unequal-mass mergers. We find that 47% of the MBHs in our population merge by z = 0. Of these, 19% have misaligned primaries and 10% have misaligned secondaries at the time of merger in our fiducial model with initial eccentricity of 0.6 and accretion rates from Illustris. The MBH misalignment fraction depends strongly on the accretion disc parameters, however. Reducing accretion rates by a factor of 100, in a thicker disc, yields 79% and 42% misalignment for primaries and secondaries, respectively. Even in the more conservative fiducial model, more than 12% of binaries experience recoils of > 500km/s, which could displace them at least temporarily from galactic nuclei. We additionally find that a significant number of systems experience strong precession.


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 498 (1) ◽  
pp. L31-L34
Author(s):  
Pierre Boldrini

ABSTRACT Using state-of-the-art high-resolution fully GPU N-body simulations, we demonstrate for the first time that the infall of a dark matter-rich satellite naturally explains a present black hole offset by subparsecs in M31. Observational data of the tidal features provide stringent constraints on the initial conditions of our simulations. The heating of the central region of M31 by the satellite via dynamical friction entails a significant black hole offset after the first pericentric passage. After having reached its maximum offset, the massive black hole sinks towards the M31 centre due to dynamical friction and it is determined to be offset by subparsecs as derived by observations.


2000 ◽  
Vol 119 (3) ◽  
pp. 1157-1171 ◽  
Author(s):  
Karl Gebhardt ◽  
Douglas Richstone ◽  
John Kormendy ◽  
Tod R. Lauer ◽  
Edward A. Ajhar ◽  
...  

2009 ◽  
Vol 692 (2) ◽  
pp. 1075-1109 ◽  
Author(s):  
S. Gillessen ◽  
F. Eisenhauer ◽  
S. Trippe ◽  
T. Alexander ◽  
R. Genzel ◽  
...  

Author(s):  
Hajime Inoue

Abstract We investigate a mechanism for a super-massive black hole at the center of a galaxy to wander in the nucleus region. A situation is supposed in which the central black hole tends to move by the gravitational attractions from the nearby molecular clouds in a nuclear bulge but is braked via the dynamical frictions from the ambient stars there. We estimate the approximate kinetic energy of the black hole in an equilibrium between the energy gain rate through the gravitational attractions and the energy loss rate through the dynamical frictions in a nuclear bulge composed of a nuclear stellar disk and a nuclear stellar cluster as observed from our Galaxy. The wandering distance of the black hole in the gravitational potential of the nuclear bulge is evaluated to get as large as several 10 pc, when the black hole mass is relatively small. The distance, however, shrinks as the black hole mass increases, and the equilibrium solution between the energy gain and loss disappears when the black hole mass exceeds an upper limit. As a result, we can expect the following scenario for the evolution of the black hole mass: When the black hole mass is smaller than the upper limit, mass accretion of the interstellar matter in the circumnuclear region, causing the AGN activities, makes the black hole mass larger. However, when the mass gets to the upper limit, the black hole loses the balancing force against the dynamical friction and starts spiraling downward to the gravity center. From simple parameter scaling, the upper mass limit of the black hole is found to be proportional to the bulge mass, and this could explain the observed correlation of the black hole mass with the bulge mass.


2020 ◽  
Vol 15 (S359) ◽  
pp. 280-282
Author(s):  
Gustavo Amaral Lanfranchi ◽  
Anderson Caproni ◽  
Jennifer F. Soares ◽  
Larissa S. de Oliveira

AbstractThe gas evolution of a typical Dwarf Spheroidal Galaxy is investigated by means of 3D hydrodynamic simulations, taking into account the feedback of type II and Ia supernovae, the outflow of an Intermediate Massive Black Hole (IMBH) and a static cored dark matter potential. When the IMBH’s outflow is simulated in an homogeneous medium a jet structure is created and a small fraction of the gas is pushed away from the galaxy. No jet structure can be seen, however, when the medium is disturbed by supernovae, but gas is still pushed away. In this case, the main driver of the gas removal are the supernovae. The interplay between the stellar feedback and the IMBH’s outflow should be taken into account.


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