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On the charge of the Galactic centre black hole

The result's identifiers

  • Result code in IS VaVaI

    <a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F47813059%3A19240%2F18%3AA0000244" target="_blank" >RIV/47813059:19240/18:A0000244 - isvavai.cz</a>

  • Result on the web

    <a href="https://academic.oup.com/mnras/article-abstract/480/4/4408/5069413?redirectedFrom=fulltext" target="_blank" >https://academic.oup.com/mnras/article-abstract/480/4/4408/5069413?redirectedFrom=fulltext</a>

  • DOI - Digital Object Identifier

    <a href="http://dx.doi.org/10.1093/mnras/sty2182" target="_blank" >10.1093/mnras/sty2182</a>

Alternative languages

  • Result language

    angličtina

  • Original language name

    On the charge of the Galactic centre black hole

  • Original language description

    The Galactic centre supermassive black hole (SMBH), in sharp contrast with its complex environment, is characterized by only three classical parameters - mass, spin, and electric charge. Its charge is poorly constrained. It is, however, usually assumed to be zero because of neutralization due to the presence of plasma. We revisit the question of the SMBII charge and put realistic limits on its value, time-scales of charging and discharging, and observable consequences of the potential, small charge associated with the Galactic centre black hole. The electric charge due to classical arguments based on the mass difference between protons and electrons is less than or similar to 10^9 C and is of a transient nature on the viscous time-scale. However, the rotation of a black hole in magnetic field generates electric field due to the twisting of magnetic field lines. This electric field can be associated with induced charge, for which we estimate an upper limit of less than or similar to 10^{15} C. Moreover, this charge is most likely positive due to an expected alignment between the magnetic field and the black hole spin. Even a small charge of this order significantly shifts the position of the innermost stable circular orbit (ISCO) of charged particles. In addition, we propose a novel observational test based on the presence of the bremsstrahlung surface brightness decrease, which is more sensitive for smaller unshielded electric charges than the black hole shadow size. Based on this test, the current upper observational limit on the charge of Sgr A* is less than or similar to 3 x 10^8 C.

  • Czech name

  • Czech description

Classification

  • Type

    J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database

  • CEP classification

  • OECD FORD branch

    10308 - Astronomy (including astrophysics,space science)

Result continuities

  • Project

    <a href="/en/project/GJ16-03564Y" target="_blank" >GJ16-03564Y: Accretion configurations in strong gravity combined with electromagnetic field</a><br>

  • Continuities

    P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Others

  • Publication year

    2018

  • Confidentiality

    S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Data specific for result type

  • Name of the periodical

    Monthly Notices of the Royal Astronomical Society

  • ISSN

    0035-8711

  • e-ISSN

    1365-2966

  • Volume of the periodical

    480

  • Issue of the periodical within the volume

    4

  • Country of publishing house

    GB - UNITED KINGDOM

  • Number of pages

    16

  • Pages from-to

    4408-4423

  • UT code for WoS article

    000449617100011

  • EID of the result in the Scopus database

    2-s2.0-85055154673