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Magnetic null points can develop near the ergosphere boundary of a rotating black hole by the combined effects of strong gravitational field and the frame-dragging mechanism. The induced electric component does not vanish an efficient…

High Energy Astrophysical Phenomena · Physics 2015-01-06 V. Karas , O. Kopacek , D. Kunneriath , J. Hamersky

Magnetic field can be amplified and twisted near a supermassive black hole residing in a galactic nucleus. At the same time magnetic null points develop near the horizon. We examine a large-scale oblique magnetic field near a rotating…

High Energy Astrophysical Phenomena · Physics 2013-07-19 V. Karas , O. Kopacek , D. Kunneriath

Understanding the mechanisms of particle acceleration from the vicinity of black holes poses a challenge. Electromagnetic effects are thought to be a prime suspect, but details still need an explanation. To this end, we study a…

High Energy Astrophysical Phenomena · Physics 2012-01-31 V. Karas , O. Kopacek , D. Kunneriath

We explore the structure of a dipole-type vacuum field of a slowly rotating magnetic star near the horizon of a supermassive black hole, where the structure of field lines becomes highly distorted by effects of strong gravity. Such a…

High Energy Astrophysical Phenomena · Physics 2018-12-13 Ondřej Kopáček , T. Tahamtan , Vladimír Karas

We discuss the role of general relativity frame dragging acting on magnetic field lines near a rotating (Kerr) black hole. Near ergosphere the magnetic structure becomes strongly influenced and magnetic null points can develop. We consider…

High Energy Astrophysical Phenomena · Physics 2015-06-04 V. Karas , O. Kopacek , D. Kunneriath

Magnetic layers are narrow regions where the field direction changes sharply. They often occur in the association with neutral points of the magnetic field. We show that an organised field can produce these structures near a rotating black…

Astrophysics · Physics 2008-12-22 V. Karas , O. Kopacek

Relativistic effects of compact objects onto electromagnetic fields in their vicinity are investigated using the test-field approximation. In particular, we study the possible emergence of magnetic null points which are astrophysically…

High Energy Astrophysical Phenomena · Physics 2019-02-27 Ondřej Kopáček , Tayebeh Tahamtan , Vladimír Karas

The electromagnetic field near a rotating black hole is being explored in educational style here. By employing analytic solutions for electrovacuum fields, we plot the surfaces of constant flux and we show how the field is dragged around…

Astrophysics · Physics 2007-05-23 Z. Budinova , M. Dovciak , V. Karas , A. Lanza

Magnetic fields play a central role in black hole astrophysics, powering relativistic jets and other energetic phenomena. While near-horizon magnetic field is usually assumed to originate from the accretion flow, additional large-scale…

High Energy Astrophysical Phenomena · Physics 2026-01-29 Madina Zhakipova , Arman Tursunov , Saken Toktarbay , Martin Kološ

Large-scale magnetic fields in the nuclear regions of protogalaxies can promote the formation and early growth of supermassive black holes (SMBHs) by direct collapse and magnetically boosted accretion. Turbulence associated with…

High Energy Astrophysical Phenomena · Physics 2023-09-06 Mitchell C. Begelman , Joseph Silk

Strong gravity and magnetic fields are key ingredients that power processes of accretion and ejection near compact objects. While the particular mechanisms that operate here are still discussed, it seems that the presence of an ordered…

High Energy Astrophysical Phenomena · Physics 2020-09-02 Ondřej Kopáček , Vladimír Karas

We study the effects of large scale magnetic fields on the dynamics of charged particles near a rotating black hole. We consider a scenario in which the initially neutral particles on geodesic orbits in the equatorial plane become ionized,…

High Energy Astrophysical Phenomena · Physics 2021-03-23 Vladimir Karas , Ondrej Kopacek

Black holes cannot support their own internal magnetic field like, for example, compact stars can. Despite this fact observations indicate that event horizons of supermassive black holes (SMBH) are threaded by field lines along which plasma…

High Energy Astrophysical Phenomena · Physics 2017-08-23 V. Karas , O. Kopacek , D. Kunneriath , M. Zajacek , A. Araudo , A. Eckart , J. Kovar

Already in the cornerstone works on astrophysical black holes published as early as in 1970s, Ruffini and collaborators have revealed potential importance of an intricate interaction between the effects of strong gravitational and…

General Relativity and Quantum Cosmology · Physics 2023-06-14 Vladimir Karas , Zdenek Stuchlik

Rotating bodies in General Relativity produce frame dragging, also known as the {\it gravitomagnetic effect} in analogy with classical electromagnetism. In this work, we study the effect of magnetic field on the gravitomagnetic effect in…

High Energy Astrophysical Phenomena · Physics 2017-01-31 Debarati Chatterjee , Chandrachur Chakraborty , Debades Bandyopadhyay

Three-dimensional electron phase space holes are shown to be positive charges on the plasma background which produce a radial electric field and force the trapped electron component into an azimuthal drift. In this way electron holes…

Space Physics · Physics 2012-04-20 R. A. Treumann , W. Baumjohann

As a black hole and neutron star approach during inspiral, the field lines of a magnetized neutron star eventually thread the black hole event horizon and a short-lived electromagnetic circuit is established. The black hole acts as a…

High Energy Astrophysical Phenomena · Physics 2013-11-28 Daniel J. D'Orazio , Janna Levin

Stationary axisymmetric magnetic fields are expelled from outer horizons of black holes as they become extremal. Extreme black holes exhibit Meissner effect also within exact Einstein--Maxwell theory and in string theories in higher…

Astrophysics · Physics 2007-05-23 J. Bicak , V. Karas , T. Ledvinka

Using the Grad-Shafranov equation, we consider a new analytical model of the black hole magnetosphere based on the assumption that the magnetic field is radial near the horizon and uniform (cylindrical) in the jet region. Within this model,…

High Energy Astrophysical Phenomena · Physics 2013-03-12 V. S. Beskin , A. A. Zheltoukhov

Combined influence of rotation of a black hole and ambient magnetic fields creates conditions for powerful astrophysical processes of accretion and outflow of matter which are observed in many systems across the range of masses; from…

High Energy Astrophysical Phenomena · Physics 2023-07-26 Ondrej Kopacek , Vladimir Karas
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