ZAJAČEK, Michal, Arman TURSUNOV, Andreas ECKART and Silke BRITZEN. On the charge of the Galactic centre black hole. Monthly Notices of the Royal Astronomical Society. 2018, vol. 480, No 4, p. 4408-4423. ISSN 0035-8711. Available from: https://dx.doi.org/10.1093/mnras/sty2182.
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Basic information
Original name On the charge of the Galactic centre black hole
Authors ZAJAČEK, Michal (703 Slovakia), Arman TURSUNOV (860 Uzbekistan, guarantor, belonging to the institution), Andreas ECKART (276 Germany) and Silke BRITZEN (276 Germany).
Edition Monthly Notices of the Royal Astronomical Society, 2018, 0035-8711.
Other information
Original language English
Type of outcome Article in a journal
Field of Study 10308 Astronomy
Country of publisher United Kingdom of Great Britain and Northern Ireland
Confidentiality degree is not subject to a state or trade secret
WWW URL
RIV identification code RIV/47813059:19240/18:A0000244
Organization unit Faculty of Philosophy and Science in Opava
Doi http://dx.doi.org/10.1093/mnras/sty2182
UT WoS 000449617100011
Keywords in English Galaxy: centre; black hole physics; radiation mechanisms: general
Tags International impact, Reviewed
Links GJ16-03564Y, research and development project.
Changed by Changed by: RNDr. Arman Tursunov, Ph.D., učo 39715. Changed: 23/4/2020 14:07.
Abstract
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.
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