scholarly journals Magnetically arrrested disk around a black hole, and jet formation

2020 ◽  
Author(s):  
Gennady Bisnovatyi-Kogan
Keyword(s):  
Black Hole ◽  
Jet Formation

Why only a small fraction of quasars are radio loud?

2018 ◽  
Vol 14 (S342) ◽  
pp. 201-204
Author(s):  
Xinwu Cao
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Angular Momentum ◽  
Angular Velocity ◽  
Strong Magnetic Field ◽  
Weak Magnetic Field ◽  
Thin Disk ◽  
Relativistic Jets ◽  
Jet Formation ◽  
The Magnetic Field

AbstractIt is still a mystery why only a small fraction of quasars contain relativistic jets. A strong magnetic field is a necessary ingredient for jet formation. Gas falls from the Bondi radius RB nearly freely to the circularization radius Rc, and a thin accretion disk is formed within Rc We suggest that the external weak magnetic field threading interstellar medium is substantially enhanced in this region, and the magnetic field at Rc can be sufficiently strong to drive outflows from the disk if the angular velocity of the gas is low at RB. In this case, the magnetic field is efficiently dragged in the disk, because most angular momentum of the disk is removed by the outflows that lead to a significantly high radial velocity. The strong magnetic field formed in this way may accelerate jets in the region near the black hole, either by the Blandford-Payne or/and Blandford-Znajek mechanisms. If the angular velocity of the circumnuclear gas is low, the field advection in the thin disk is inefficient, and it will appear as a radio-quiet (RQ) quasar.

General Relativistic Simulations of Early Jet Formation in a Rapidly Rotating Black Hole Magnetosphere

2000 ◽  
Vol 536 (2) ◽  
pp. 668-674 ◽  
Author(s):  
Shinji Koide ◽  
David L. Meier ◽  
Kazunari Shibata ◽  
Takahiro Kudoh
Keyword(s):  
Black Hole ◽  
Jet Formation ◽  
Rotating Black Hole ◽  
General Relativistic

scholarly journals General Relativistic Simulation of Jet Formation from Magnetized Accretion Disk

1997 ◽  
Vol 163 ◽  
pp. 667-671
Author(s):  
Shinji Koide ◽  
Kazunari Shibata ◽  
Takahiro Kudoh
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Accretion Disk ◽  
Galactic Nuclei ◽  
Lorentz Factor ◽  
Numerical Code ◽  
Jet Formation ◽  
Relativistic Jet ◽  
Relativistic Regime ◽  
General Relativistic

AbstractRecently, superluminal motions are observed not only from active galactic nuclei but also in our Galaxy. These phenomena are explained as relativistic jets propagating almost toward us with Lorentz factor more than 2. For the formation of such a relativistic jet, magnetically driven mechanism around a black hole is most promising. We have extended the 2.5D Newtonian MHD jet model (Shibata & Uchida 1986) to general relativistic regime. For this purpose, we have developed a general relativistic magnetohydrodynamic (GRMHD) numerical code and applied it to the simulation of the magnetized accretion disk around a black hole. We have found the formation of magnetically driven jets with 86 percent of light velocity (i.e. Lorentz factor ~ 2.0).

scholarly journals Magnetization of AGN jets as imposed by leptonic models of luminous blazars

2014 ◽  
Vol 10 (S313) ◽  
pp. 85-86
Author(s):  
Mateusz Janiak ◽  
Marek Sikora ◽  
Rafal Moderski
Keyword(s):  
Black Hole ◽  
Kinetic Energy ◽  
Energy Flux ◽  
Broad Line ◽  
Jet Formation ◽  
Frequency Dependent ◽  
Broad Line Region ◽  
Line Region ◽  
Γ Ray ◽  
Dusty Torus

AbstractRecent measurements of frequency-dependent shift of radio-core locations indicate that the ratio of the magnetic to kinetic energy flux (the σ parameter) is of the order of unity. These results are consistent with predictions of magnetically-arrested-disk (MAD) models of a jet formation, but contradict the predictions of leptonic models of γ-ray production in luminous blazars. We demonstrate this discrepancy by computing the γ-ray-to-synchrotron luminosity ratio (the q parameter) as a function of a distance from the black hole for different values of σ and using both spherical and planar models for broad-line region and dusty torus. We find that it is impossible to reproduce observed q ≫ 1 for jets with σ ≥ 1. This may indicate that blazar radiation is produced in reconnection layers or in spines of magnetically stratified jets.

scholarly journals COMPLETE MULTIWAVELENGTH EVOLUTION OF GALACTIC BLACK HOLE TRANSIENTS DURING OUTBURST DECAY. I. CONDITIONS FOR “COMPACT” JET FORMATION

2013 ◽  
Vol 779 (2) ◽  
pp. 95 ◽  
Author(s):  
E. Kalemci ◽  
T. Dinçer ◽  
J. A. Tomsick ◽  
M. M. Buxton ◽  
C. D. Bailyn ◽  
...  
Keyword(s):  
Black Hole ◽  
Jet Formation ◽  
Galactic Black Hole
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