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Related papers: Black Holes as Cosmic Dynamos

200 papers

We compute a series of three-dimensional general relativistic magnetohydrodynamic simulations of accretion flows in the Kerr metric to investigate the properties of the unbound outflows that result. The overall strength of these outflows…

Astrophysics · Physics 2009-11-13 John F. Hawley , Julian H. Krolik

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

I show that Eddington accretion episodes in AGN are likely to produce winds with velocities $v \sim 0.1c$ and ionization parameters up to $\xi \sim 10^4$ (cgs), implying the presence of resonance lines of helium-- and hydrogenlike iron.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 A. R. King

Microquasars provide new insights into: 1) the physics of relativistic jets from black holes, 2) the connection between accretion and ejection, and 3) the physical mechanisms in the formation of stellar-mass black holes. Furthermore, the…

Astrophysics · Physics 2009-11-13 I. F. Mirabel

We use results from simulations of the production of magnetohydrodynamic jets around black holes to derive the cosmic spin history of the most massive black holes. We assume that the efficiency of jet production is a monotonic function of…

High Energy Astrophysical Phenomena · Physics 2015-05-30 Alejo Martinez-Sansigre , Steve Rawlings

Tidal disruption of main sequence stars by black holes has generally been thought to lead to a signal dominated by UV emission. If, however, the black hole spins rapidly and the poloidal magnetic field intensity on the black hole horizon is…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Julian H. Krolik , Tsvi Piran

Accreting black holes are observed to launch relativistic, collimated jets of matter and radiation. In some sources, discrete ejections have been detected with highly relativistic velocities. These particular sources typically have very…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Ashley L. King , Jon M. Miller , Michael Bietenholz , Kayhan Gultekin , Mark Reynolds , Amy Mioduszewski , Michael Rupen , Norbert Bartel

In cuspy atmospheres, jets driven by supermassive black holes (BHs) offset radiative cooling. The jets fire episodically, but often enough that the cuspy atmosphere does not move very far towards a cooling catastrophe in the intervals of…

Astrophysics · Physics 2009-11-10 James Binney

Theoretical models for the production of relativistic jets from active galactic nuclei predict that jet power arises from the spin and mass of the central black hole, as well as the magnetic field near the event horizon. The physical…

High Energy Astrophysical Phenomena · Physics 2015-06-23 G. Ghisellini , F. Tavecchio , L. Maraschi , A. Celotti , T. Sbarrato

We present the theoretical arguments and describe the accumulating experimental evidence that jets, powered by supermassive black holes, are true cosmic accelerators. They produce photons of TeV energy, possible higher, and may be the…

Astrophysics · Physics 2007-05-23 F. Halzen

According to the currently favored picture, relativistic jets in active galactic nuclei (AGN) are launched in the vicinity of the black hole by magnetic fields extracting energy from the spinning black hole or the accretion disk. In the…

High Energy Astrophysical Phenomena · Physics 2017-06-28 Talvikki Hovatta

Rotating black holes are known to launch relativistic jets and accelerate particles provided they accrete a magnetized plasma. However, it remains unclear how the global magnetic field orientation affects the jet powering efficiency. Here,…

High Energy Astrophysical Phenomena · Physics 2025-08-27 Enzo Figueiredo , Benoît Cerutti , Kyle Parfrey

Since a black hole does not emit light from its interior, nor does it have a surface on which light from nearby sources can be reflected, observational study of black hole physics requires observing the gravitational impact of the black…

High Energy Astrophysical Phenomena · Physics 2023-04-21 Marianne Vestergaard , Kayhan Gültekin

We present various instability mechanisms in the accreting black hole systems which might indicate at the connection between the accretion disk and jet. The jets observed in microquasars can have a persistent or blobby morphology.…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Agnieszka Janiuk , Bozena Czerny , Monika Moscibrodzka , Aneta Siemiginowska

We investigate time-dependent inviscid hydrodynamical accretion flows onto a black hole using numerical simulations. We consider the accretion that consists of hot tenuous gas with low specific angular momentum and cold dense gas with high…

Astrophysics · Physics 2009-10-30 Koji Nobuta , Tomoyuki Hanawa

The theoretical model suggests that relativistic jets of AGN rely on the black hole spin and/or accretion. We study the relationship between jet, accretion, and spin using supermassive black hole samples with reliable spin of black holes.…

High Energy Astrophysical Phenomena · Physics 2024-10-11 Yongyun Chen , Qiusheng Gu , Jianghe Yang , Junhui Fan , Xiaoling Yu , Dingrong Xiong , Nan Ding , Xiaotong Guo

Accreting black holes produce collimated outflows, or jets, that traverse many orders of magnitude in distance, accelerate to relativistic velocities, and collimate into tight opening angles. Of these, perhaps the least understood is jet…

High Energy Astrophysical Phenomena · Physics 2019-09-25 Koushik Chatterjee , Matthew Liska , Alexander Tchekhovskoy , Sera B. Markoff

Relativistic jets from black holes can extract energy not only from accretion but also directly from the black hole's spin, as described by the Blandford-Znajek mechanism. A longstanding question is whether magnetic flux can accumulate near…

High Energy Astrophysical Phenomena · Physics 2026-02-27 Antonios Nathanail

Black holes drive powerful plasma jets to relativistic velocities. This plasma should be collisionless, and self-consistently supplied by pair creation near the horizon. We present general-relativistic collisionless plasma simulations of…

High Energy Astrophysical Phenomena · Physics 2019-01-30 Kyle Parfrey , Alexander Philippov , Benoit Cerutti

One of the major open questions related to the production of jets by accreting black holes is: why do sources with similar accretion powers produce so vastly different jet powers? What conditions are required to make a powerful jet? If jets…

High Energy Astrophysical Phenomena · Physics 2025-02-19 Tuomas Savolainen , Wara Chamani