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
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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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