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Current High Energy Emission from Black Holes

Blandford, R. D. (2002) Current High Energy Emission from Black Holes. In: Current High-Energy Emission Around Black Holes. World Scientific , Singapore, pp. 199-216. ISBN 9789812777959.

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Two related topics are discussed. 1. Accretion onto black holes at low and high (though not very high) rates is believed to proceed adiabatically (ie non-radiatively). It is argued that the liberated energy is carried off by an outflow, probably involving almost all of the gas that is supplied. Two dimensional, fluid, accretion disks, in which mass, angular momentum and energy are transported to the disk surface, are summarized. It is conjectured that relatively minor changes are needed to describe magnetised disks. By contrast, the disk surface physics is argued to dictate the character of the outflow. 2. Ultrarelativistic jets appear to be produced by active galactic nuclei (AGN), pulsars and γ-ray bursts (GRB). In all three cases, it is argued that the power is generated electromagnetically by a magnetic rotator, (in a DC not AC form), and transported in this manner to the emission site. A model of a relativistically expanding electromagnetic shell is described and used to provide a simple model of a GRB in which the γ-rays are produced by unstable electrical currents flowing along the rotation axis. The shell drives a relativistic blast wave into the surrounding medium with a speed that varies with latitude and whose afterglow emission may exhibit achromatic breaks. Similar processes may be at work in non-relativistic plerions like the Crab Nebula and, possibly, AGN jets. The observational implications of these two classes of model and the prospects for performing instructive, numerical experiments to elucidate them further are briefly outlined.

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Blandford, R. D.0000-0002-1854-5506
Additional Information:© 2002 World Scientific Publishing. I thank the organisers of this workshop for their gracious and generous hospitality, my colleagues Mitch Begelman and Max Lyutikov for their collaboration on the above and several of the conference participants for discussion which helped to clarify some of the arguments I have presented. Support under NASA grant 5-2837 is gratefully acknowledged.
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Official Citation:CURRENT HIGH ENERGY EMISSION FROM BLACK HOLES R. D. BLANDFORD Current High-Energy Emission Around Black Holes. May 2002, 199-216
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:98928
Deposited By: George Porter
Deposited On:07 Oct 2019 14:39
Last Modified:07 Oct 2019 14:39

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