English
Related papers

Related papers: Black Holes as Cosmic Dynamos

200 papers

A brief summary of the properties of astrophysical black holes is presented. Various modes of accretion are distinguished, corresponding to accretion at rates from well below to well above the Eddington rate. The importance of mass loss is…

Astrophysics · Physics 2007-05-23 Roger. D. Blandford

Accretion supermassive black holes in the center of active galaxies usually produce ``jets''-collimated bipolar outflows of relativistic particles. Magnetic fields near the black hole event horizon may play a crucial role in the formation…

High Energy Astrophysical Phenomena · Physics 2025-03-05 Yongyun Chen , Qiusheng Gu , Junhui Fan , Xiaotong Guo , Xiaoling Yu , Nan Ding , Dingrong Xiong

Extragalactic relativistic jets are engines able to carry out to large distances a huge amount of power, not only in the form of radiation, but especially in the form of kinetic energy of matter and fields. As such, they can be thought as…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 G. Ghisellini

Steady axisymmetric outflows originating at the hot coronal magnetosphere of a Schwarzschild black hole and surrounding accretion disk are studied in the framework of general relativistic magnetohydrodynamics (GRMHD). The assumption of…

Astrophysics · Physics 2009-11-11 Z. Meliani , C. Sauty , N. Vlahakis , K. Tsinganos , E. Trussoni

We investigate some features of the hydrodynamics and neutrino physics in the (predominantly) electron-positron plasma above a hyperaccreting disk (or torus) around a black hole, a conjectured engine for a short gamma ray burst. We suggest…

Astrophysics · Physics 2008-11-26 R. F. Sawyer

We discuss the properties of magnetically dominated jet-like outflows from stellar mass black holes surrounded by debris tori resulting from neutron star disruption. These jets may have narrow cores (along the rotation axis) which are…

Astrophysics · Physics 2015-06-24 P. Meszaros , M. J. Rees

Theoretical models show that the power of relativistic jets of active galactic nuclei depends on the spin and mass of the central supermassive black holes, as well as the accretion. Here we report an analysis of archival observations of a…

High Energy Astrophysical Phenomena · Physics 2021-06-09 Yongyun Chen , Qiusheng Gu , Junhui Fan , Hongyan Zhou , Yefei Yuan , Weimin Gu , Qinwen Wu , Dingrong Xiong , Xiaotong Guo , Nan Ding , Xiaoling Yu

We propose a scenario for launching relativistic jets from rotating black holes, in which small-scale magnetic flux loops, sustained by disc turbulence, are forced to inflate and open by differential rotation between the black hole and the…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Kyle Parfrey , Dimitrios Giannios , Andrei M. Beloborodov

A model is presented in which the strongest radio-emitting jet outflows are produced in black hole systems when the accretion is a geometrically thick ($H/R \sim 1$) inflow ({\it e.g.}, ADAF, CDAF) {\em and} if the black hole is rotating.…

Astrophysics · Physics 2009-10-31 David L. Meier

This is the fourth paper of our series of works studying winds from hot accretion flows around black holes. In the first two papers, we have shown the existence of strong winds in hot accretion flows using hydrodynamical and…

High Energy Astrophysical Phenomena · Physics 2021-06-30 Hai Yang , Feng Yuan , Ye-fei Yuan , Christopher J. White

In this book chapter, we will briefly review the current empirical understanding of the relation between accretion state and and outflows in accreting stellar mass black holes. The focus will be on the empirical connections between X-ray…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Rob Fender , Elena Gallo

Supermassive black holes lying in the center of galaxies can launch relativistic jets of plasma along their polar axis. The physics of black-hole jets is a very active research topic in astrophysics, owing to the fact that many questions…

High Energy Astrophysical Phenomena · Physics 2020-12-25 Matteo Cerruti

Astronomers have discovered two populations of black holes: (i) stellar-mass black holes with masses in the range 5 to 30 solar masses, millions of which are present in each galaxy in the universe, and (ii) supermassive black holes with…

High Energy Astrophysical Phenomena · Physics 2014-07-23 Ramesh Narayan , Jeffrey E. McClintock

Relativistic outflows are a common phenomenon in accreting black holes. Despite the enormous differences in scale, stellar-mass black holes in binaries and supermassive black holes in Galactic Nuclei produce jets with analogous properties.…

Astrophysics · Physics 2009-10-31 I. F. Mirabel

An axisymmetric MHD model is examined analytically to illustrate some key aspects of the physics of hot and magnetized outflows which originate in the near environment of a central gravitating body. By analyzing the asymptotical behaviour…

Astrophysics · Physics 2007-05-23 C. Sauty , K. Tsinganos , E. Trussoni

Most powerful jets are observed to emanate from accreting black hole systems. Recent quasi-stationary radiative MHD calculations reveal that jet-launching start in the innermost region of a transition layer (:TL), which is located between…

Astrophysics · Physics 2007-05-23 A. Hujeirat

In the standard paradigm, astrophysical black holes can be described solely by their mass and angular momentum - commonly referred to as `spin' - resulting from the process of their birth and subsequent growth via accretion. Whilst the mass…

High Energy Astrophysical Phenomena · Physics 2017-12-19 Matthew Middleton

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…

High Energy Astrophysical Phenomena · Physics 2021-01-25 Shane W. Davis , Alexander Tchekhovskoy

Most black holes (BHs) formed in collapsing stars have low spin, though some are expected to acquire a magnetic accretion disk during the collapse. While such BH disks can launch magnetically driven winds, their physics and observational…

High Energy Astrophysical Phenomena · Physics 2025-03-11 Justin Bopp , Ore Gottlieb

Accreting black hole sources show variable outflows at different mass scales. For instance, in the case of galactic nuclei, our own galactic center Sgr A* exhibits flares and outbursts in the X-ray and infrared bands. Recent studies suggest…

High Energy Astrophysical Phenomena · Physics 2024-07-17 Bestin James , Agnieszka Janiuk , Vladimir Karas