Non-thermal Processes in Black-Hole-Jet Magnetospheres

TL;DR

This paper reviews non-thermal particle acceleration and emission processes in supermassive black hole magnetospheres, exploring mechanisms like electric field acceleration, magnetic reconnection, and their implications for high-energy astrophysical phenomena.

Contribution

It provides a comprehensive overview of non-thermal processes near black holes, highlighting recent observational progress and discussing key acceleration mechanisms and their efficiency constraints.

Findings

Identification of electric field acceleration as a key process

Insights into ultra-high energy cosmic ray production

Analysis of efficiency constraints in black hole magnetospheres

Abstract

The environs of supermassive black holes are among the universe's most extreme phenomena. Understanding the physical processes occurring in the vicinity of black holes may provide the key to answer a number of fundamental astrophysical questions including the detectability of strong gravity effects, the formation and propagation of relativistic jets, the origin of the highest energy gamma-rays and cosmic-rays, and the nature and evolution of the central engine in Active Galactic Nuclei (AGN). As a step towards this direction, this paper reviews some of the progress achieved in the field based on observations in the very high energy domain. It particularly focuses on non-thermal particle acceleration and emission processes that may occur in the rotating magnetospheres originating from accreting, supermassive black hole systems. Topics covered include direct electric field acceleration in the black hole's magnetosphere, ultra-high energy cosmic ray production, Blandford-Znajek mechanism, centrifugal acceleration and magnetic reconnection, along with the relevant efficiency constraints imposed by interactions with matter, radiation and fields. By way of application, a detailed discussion of well-known sources (Sgr A*; Cen A; M87; NGC1399) is presented.