Black Hole Spin-Up in the Light of General Relativistic MHD Simulations

2006 ◽  
pp. 274-283 ◽  
Author(s):  
J.H. Krolik
Keyword(s):  
Black Hole ◽  
Black Hole Spin ◽  
Mhd Simulations ◽  
General Relativistic

scholarly journals Influence of the geometric configuration of accretion flow on the black hole spin dependence of relativistic acoustic geometry

2018 ◽  
Vol 27 (03) ◽  
pp. 1850023 ◽  
Author(s):  
Pratik Tarafdar ◽  
Tapas K. Das
Keyword(s):  
Black Hole ◽  
Kerr Black Hole ◽  
Geometric Configuration ◽  
Surface Gravity ◽  
Linear Perturbation ◽  
Flow Profile ◽  
White Hole ◽  
Accretion Flow ◽  
Black Hole Spin ◽  
General Relativistic

Linear perturbation of general relativistic accretion of low angular momentum hydrodynamic fluid onto a Kerr black hole leads to the formation of curved acoustic geometry embedded within the background flow. Characteristic features of such sonic geometry depend on the black hole spin. Such dependence can be probed by studying the correlation of the acoustic surface gravity [Formula: see text] with the Kerr parameter [Formula: see text]. The [Formula: see text]–[Formula: see text] relationship further gets influenced by the geometric configuration of the accretion flow structure. In this work, such influence has been studied for multitransonic shocked accretion where linear perturbation of general relativistic flow profile leads to the formation of two analogue black hole-type horizons formed at the sonic points and one analogue white hole-type horizon which is formed at the shock location producing divergent acoustic surface gravity. Dependence of the [Formula: see text]–[Formula: see text] relationship on the geometric configuration has also been studied for monotransonic accretion, over the entire span of the Kerr parameter including retrograde flow. For accreting astrophysical black holes, the present work thus investigates how the salient features of the embedded relativistic sonic geometry may be determined not only by the background spacetime, but also by the flow configuration of the embedding matter.

scholarly journals General relativistic simulations of black-hole–neutron-star mergers: Effects of black-hole spin

2009 ◽  
Vol 79 (4) ◽  
Author(s):  
Zachariah B. Etienne ◽  
Yuk Tung Liu ◽  
Stuart L. Shapiro ◽  
Thomas W. Baumgarte
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Black Hole Spin ◽  
General Relativistic

scholarly journals Magnetohydrodynamics Simulations of Active Galactic Nucleus Disks and Jets

2020 ◽  
Vol 58 (1) ◽  
pp. 407-439
Author(s):  
Shane W. Davis ◽  
Alexander Tchekhovskoy
Keyword(s):  
Black Hole ◽  
Accretion Disk ◽  
Surrounding Medium ◽  
Observational Constraints ◽  
Disk Model ◽  
Accretion Flow ◽  
Accretion Flows ◽  
Black Hole Spin ◽  
Spiral Density Waves ◽  
Mhd Simulations

There is a broad consensus that accretion onto supermassive black holes and consequent jet formation power the observed emission from active galactic nuclei (AGNs). However, there has been less agreement about how jets form in accretion flows, their possible relationship to black hole spin, and how they interact with the surrounding medium. There have also been theoretical concerns about instabilities in standard accretion disk models and lingering discrepancies with observational constraints. Despite seemingly successful applications to X-ray binaries, the standard accretion disk model faces a growing list of observational constraints that challenge its application to AGNs. Theoretical exploration of these questions has become increasingly reliant on numerical simulations owing to the dynamic nature of these flows and the complex interplay between hydrodynamics, magnetic fields, radiation transfer, and curved spacetime. We conclude the following: ▪  The advent of general relativistic magnetohydrodynamics (MHD) simulations has greatly improved our understanding of jet production and its dependence on black hole spin. ▪  Simulation results show both disks and jets are sensitive to the magnetic flux threading the accretion flow as well as possible misalignment between the angular momentum of the accretion flow and the black hole spin. ▪  Radiation MHD simulations are providing new insights into the stability of luminous accretion flows and highlighting the potential importance of radiation viscosity, UV opacity from atoms, and spiral density waves in AGNs.

scholarly journals Jets from Black Hole Magnetospheres

2000 ◽  
Vol 195 ◽  
pp. 265-272
Author(s):  
K. Shibata ◽  
S. Koide ◽  
T. Kudoh ◽  
S. Aoki
Keyword(s):  
Black Hole ◽  
Strong Shock ◽  
Layered Shell ◽  
Frame Dragging ◽  
Accretion Flow ◽  
Mhd Simulations ◽  
Pressure Region ◽  
General Relativistic ◽  
Strong Shock Waves ◽  
High Pressure Region

Recent general-relativistic MHD simulations of jets ejected from black-hole magnetospheres (for both Schwarzschild and Kerr holes) have revealed that (1) strong shock waves are formed in the accretion flow inside 3rs, (2) jets show two-layered shell structure consisting of a gas-pressure driven jet and a magnetically driven jet, the former being accelerated from a high-pressure region heated by strong shocks, and (3) in the case of a Kerr hole, magnetically driven jets are produced from the ergosphere by the effect of frame dragging.

General relativistic MHD simulations of black hole accretion disks and jets

2007 ◽  
Vol 311 (1-3) ◽  
pp. 117-125 ◽  
Author(s):  
John F. Hawley ◽  
Kris Beckwith ◽  
Julian H. Krolik
Keyword(s):  
Black Hole ◽  
Accretion Disks ◽  
Black Hole Accretion ◽  
Mhd Simulations ◽  
General Relativistic ◽  
Hole Accretion

scholarly journals Black hole spin dependence of general relativistic multi-transonic accretion close to the horizon

New Astronomy ◽  
2015 ◽  
Vol 37 ◽  
pp. 81-104 ◽  
Author(s):  
Tapas K. Das ◽  
Sankhasubhra Nag ◽  
Swathi Hegde ◽  
Sourav Bhattacharya ◽  
Ishita Maity ◽  
...  
Keyword(s):  
Black Hole ◽  
Spin Dependence ◽  
Black Hole Spin ◽  
General Relativistic

scholarly journals Formation of precessing jets by tilted black hole discs in 3D general relativistic MHD simulations

2017 ◽  
Vol 474 (1) ◽  
pp. L81-L85 ◽  
Author(s):  
M Liska ◽  
C Hesp ◽  
A Tchekhovskoy ◽  
A Ingram ◽  
M van der Klis ◽  
...  
Keyword(s):  
Black Hole ◽  
Mhd Simulations ◽  
General Relativistic
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