Magnetic fields in thin accretion disks around black holes

1993 ◽  
pp. 193-196
Author(s):  
R. Khanna ◽  
M. Camenzind
Keyword(s):  
Black Holes ◽  
Magnetic Fields ◽  
Accretion Disks

Magnetic fields of accretion disks and outflows in prograde and retrograde black holes

2013 ◽  
Vol 334 (3) ◽  
pp. 264-267 ◽  
Author(s):  
Yu.N. Gnedin ◽  
M.Yu. Piotrovich ◽  
S.D. Buliga ◽  
T.M. Natsvlishvili
Keyword(s):  
Black Holes ◽  
Magnetic Fields ◽  
Accretion Disks

scholarly journals Influence of Cosmic Repulsion and Magnetic Fields on Accretion Disks Rotating around Kerr Black Holes

Universe ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 26 ◽  
Author(s):  
Zdeněk Stuchlík ◽  
Martin Kološ ◽  
Jiří Kovář ◽  
Petr Slaný ◽  
Arman Tursunov
Keyword(s):  
Magnetic Field ◽  
Black Holes ◽  
Magnetic Fields ◽  
Accretion Disks ◽  
Vacuum Energy ◽  
High Energy ◽  
Supermassive Black Holes ◽  
Ultra High Energy ◽  
Thin And Thick Disks ◽  
High Energy Particles

We present a review of the influence of cosmic repulsion and external magnetic fields on accretion disks rotating around rotating black holes and on jets associated with these rotating configurations. We consider both geometrically thin and thick disks. We show that the vacuum energy represented by the relic cosmological constant strongly limits extension of the accretion disks that is for supermassive black holes comparable to extension of largest galaxies, and supports collimation of jets at large distances from the black hole. We further demonstrate that an external magnetic field crucially influences the fate of ionized Keplerian disks causing creation of winds and jets, enabling simultaneously acceleration of ultra-high energy particles with energy up to 10 21 eV around supermassive black holes with M ∼ 10 10 M ⊙ surrounded by sufficiently strong magnetic field with B ∼ 10 4 G. We also show that the external magnetic fields enable existence of “levitating” off-equatorial clouds or tori, along with the standard equatorial toroidal structures, if these carry a non-vanishing, appropriately distributed electric charge.

Spins of Supermassive Black Holes and the Magnetic Fields of Accretion Disks in Active Galactic Nuclei with Maser Emission

Astrophysics ◽  
2014 ◽  
Vol 57 (2) ◽  
pp. 163-175 ◽  
Author(s):  
Yu. N. Gnedin ◽  
V. N. Globina ◽  
M. Yu. Piotrovich ◽  
S. D. Buliga ◽  
T. M. Natsvlishvili
Keyword(s):  
Black Holes ◽  
Magnetic Fields ◽  
Active Galactic Nuclei ◽  
Accretion Disks ◽  
Galactic Nuclei ◽  
Supermassive Black Holes ◽  
Maser Emission

scholarly journals Vortex generation in the early Universe

2020 ◽  
Vol 642 ◽  
pp. L6
Author(s):  
Chinmoy Bhattacharjee ◽  
David J. Stark
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Magnetic Fields ◽  
Accretion Disk ◽  
Early Universe ◽  
Accretion Disks ◽  
Disk Model ◽  
Spacetime Curvature ◽  
Vorticity Generation ◽  
Biermann Battery

Context. Accretion disks formed near primordial black holes can be sources of seed magnetic fields in the early Universe. In particular, the Biermann battery mechanism has been shown to generate primordial magnetic fields in an unmagnetized and turbulence-free accretion disk, but this depends on a delicate misalignment of density and pressure gradients in plasmas. Aims. We aim to reformulate the question of magnetogenesis in the context of plasma generalized vorticity and to search for a more robust mechanism of vorticity generation in the early Universe. Methods. We utilize the electro-vortical formalism in curved spacetime, which treats the plasma flow and electromagnetic field on an equal footing, and apply it to a thin accretion disk model near a rotating black hole. Results. We present a spacetime curvature-driven mechanism that persists even in the absence of the Biermann battery. We explore the vorticity and enstrophy generation rate dependencies on black hole masses and spin rates. Conclusions. Analysis indicates that the accretion disks around lower-mass, faster rotating black holes contribute the greatest amount to the enstrophy and vorticity generation rates from the spacetime curvature drive. The shorter turning radii at which the sign of the vorticity changes – corresponding with this region of phase space – may favor these length scales in vortical structure formation and subsequent evolution.

scholarly journals Retrograde versus Prograde Models of Accreting Black Holes

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
David Garofalo
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Magnetic Fields ◽  
Observational Data ◽  
Accretion Disks ◽  
General Consensus ◽  
Rotating Black Holes

There is a general consensus that magnetic fields, accretion disks, and rotating black holes are instrumental in the generation of the most powerful sources of energy in the known universe. Nonetheless, because magnetized accretion onto rotating black holes involves both the complications of nonlinear magnetohydrodynamics that currently cannot fully be treated numerically, and uncertainties about the origin of magnetic fields that at present are part of the input, the space of possible solutions remains less constrained. Consequently, the literature still bears witness to the proliferation of rather different black hole engine models. But the accumulated wealth of observational data is now sufficient to meaningfully distinguish between them. It is in this light that this critical paper compares the recent retrograde framework with standard “spin paradigm” prograde models.

scholarly journals Gaseous Disks in the Nuclei of Elliptical Galaxies

1997 ◽  
Vol 163 ◽  
pp. 620-625 ◽  
Author(s):  
H. Ford ◽  
Z. Tsvetanov ◽  
L. Ferrarese ◽  
G. Kriss ◽  
W. Jaffe ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Accretion Disks ◽  
Large Scale ◽  
Elliptical Galaxies ◽  
Central Mass ◽  
Massive Black Holes ◽  
Radio Jets

AbstractHST images have led to the discovery that small (r ~ 1″ r ~ 100 – 200 pc), well-defined, gaseous disks are common in the nuclei of elliptical galaxies. Measurements of rotational velocities in the disks provide a means to measure the central mass and search for massive black holes in the parent galaxies. The minor axes of these disks are closely aligned with the directions of the large–scale radio jets, suggesting that it is angular momentum of the disk rather than that of the black hole that determines the direction of the radio jets. Because the disks are directly observable, we can study the disks themselves, and investigate important questions which cannot be directly addressed with observations of the smaller and unresolved central accretion disks. In this paper we summarize what has been learned to date in this rapidly unfolding new field.

scholarly journals EFFECTS OF MAGNETIC FIELDS ON THE DISKOSEISMIC MODES OF ACCRETING BLACK HOLES

2008 ◽  
Vol 690 (2) ◽  
pp. 1386-1392 ◽  
Author(s):  
Wen Fu ◽  
Dong Lai
Keyword(s):  
Black Holes ◽  
Magnetic Fields
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