Electron-positron cascade in magnetospheres of spinning black holes

作     者：Alexander L. Ford Brett D. Keenan Mikhail V. Medvedev 

作者机构：Department of Physics and Astronomy University of Kansas Lawrence Kansas 66045 USA Los Alamos National Lab Los Alamos NM 87545 Institute for Theory and Computation Harvard University Cambridge Massachusetts 02138 USA Laboratory for Nuclear Science Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Department of Physics and Astronomy University of Kansas Lawrence KS 66045 

出 版 物：《Physical Review D》 (Phy. Rev. D)

年 卷 期：2018年第98卷第6期

页      面：063016-063016页

核心收录：

基　　金：Institute for Theory and Computation at Harvard U.S. Department of Energy, USDOE, (DE-SC0016368) U.S. Department of Energy, USDOE 

主　　题：Electromagnetic radiation astronomy Gamma ray astronomy Space & astrophysical plasma Astronomical black holes Astrophysical jets 

摘      要：We quantitatively study the stationary, axisymmetric, force-free magnetospheres of spinning (Kerr) black holes (BHs) and the conditions needed for relativistic jets to be powered by the Blandford-Znajek mechanism. These jets could be from active galactic nuclei, blazars, quasars, microquasars, radioactive galaxies, and other systems that host Kerr BHs. The structure of the magnetosphere determines how the BH energy is extracted, e.g., via the Blandford-Znajek mechanism, which converts the BH rotational energy into Poynting flux. The key assumption is the force-free condition, which requires the presence of plasma with the density being above the Goldreich-Julian density. Unlike neutron stars, which in principle can supply electrons from the surface, BHs cannot supply plasma at all. The plasma must be generated in situ via an electron-positron cascade, presumably in the gap region. Here we study varying conditions that provide a sufficient amount of plasma for the Blandford-Znajek mechanism to work effectively.