Komissarov, SS orcid.org/0000-0003-4545-9774 (2021) Electrically-charged black holes and the Blandford-Znajek mechanism. Monthly Notices of the Royal Astronomical Society. stab2686. ISSN 0035-8711
Abstract
Recently, it was claimed by King & Pringle that accretion of electric charge by a black hole rotating in an aligned external magnetic field results in a “dead” vacuum magnetosphere, where the electric field is totally screened, no vacuum breakdown is possible, and the Blandford-Znajek mechanism cannot operate. Here we study in details the properties of the Wald solution for electrically charged black holes discussed in their paper. Our results show that the claim is erroneous as in the solution with the critical charge q0 = 2aB0 there exists a drop of electrostatic potential along all magnetic field lines except the one coinciding with the symmetry axis. It is also found that while uncharged rotating black holes expel external vacuum magnetic field from their event horizon (the Meissner effect), electric charging of black holes pulls the magnetic field lines back on it, resembling what has been observed in some previous force-free, RMHD and PIC simulations of black hole magnetospheres. This suggests that accretion of electric charge may indeed be a feature of the black hole electrodynamics. However, our analysis shows that the value q0 of the BH charge given by Wald is likely to be only an upper limit, and that the actual value depends of the details of the magnetospheric physics.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society This is a pre-copyedited, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record: Serguei S Komissarov, Electrically-charged black holes and the Blandford-Znajek mechanism, Monthly Notices of the Royal Astronomical Society, 2021;, stab2686, is available online at: https://doi.org/10.1093/mnras/stab2686 |
Keywords: | black hole physics, magnetic fields, galaxies: jets, stars: jets |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mathematics (Leeds) > Applied Mathematics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 01 Oct 2021 10:48 |
Last Modified: | 01 Oct 2021 10:48 |
Status: | Published online |
Publisher: | Oxford University Press (OUP) |
Identification Number: | 10.1093/mnras/stab2686 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:178607 |