Constraining the charge of the Galactic centre black hole

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F47813059%3A19240%2F19%3AA0000565" target="_blank" >RIV/47813059:19240/19:A0000565 - isvavai.cz</a>

Výsledek na webu

<a href="https://iopscience.iop.org/article/10.1088/1742-6596/1258/1/012031" target="_blank" >https://iopscience.iop.org/article/10.1088/1742-6596/1258/1/012031</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1742-6596/1258/1/012031" target="_blank" >10.1088/1742-6596/1258/1/012031</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Constraining the charge of the Galactic centre black hole

Popis výsledku v původním jazyce

In this contribution, we summarize our results concerning the observational constraints on the electric charge associated with the Galactic centre black hole - Sgr A*. According to the no-hair theorem, every astrophysical black hole, including supermassive black holes, is characterized by at most three classical, externally observable parameters - mass, spin, and the electric charge. While the mass and the spin have routinely been measured by several methods, the electric charge has usually been neglected, based on the arguments of efficient discharge in astrophysical plasmas. From a theoretical point of view, the black hole can attain charge due to the mass imbalance between protons and electrons in fully ionized plasmas, which yields about ~ 10^8 C for Sgr A*. The second, induction mechanism concerns rotating Kerr black holes embedded in an external magnetic field, which leads to electric field generation due to the twisting of magnetic field lines. This electric field can be associated with the induced Wald charge, for which we calculate the upper limit of ~ 10^(15) C for Sgr A*. Although the maximum theoretical limit of ~ 10^(15) C is still 12 orders of magnitude smaller than the extremal charge of Sgr A*, we analyse a few astrophysical consequences of having a black hole with a small charge in the Galactic centre. Two most prominent ones are the effect on the X-ray bremsstrahlung profile and the effect on the position of the innermost stable circular orbit.

Název v anglickém jazyce

Constraining the charge of the Galactic centre black hole

Popis výsledku anglicky

In this contribution, we summarize our results concerning the observational constraints on the electric charge associated with the Galactic centre black hole - Sgr A*. According to the no-hair theorem, every astrophysical black hole, including supermassive black holes, is characterized by at most three classical, externally observable parameters - mass, spin, and the electric charge. While the mass and the spin have routinely been measured by several methods, the electric charge has usually been neglected, based on the arguments of efficient discharge in astrophysical plasmas. From a theoretical point of view, the black hole can attain charge due to the mass imbalance between protons and electrons in fully ionized plasmas, which yields about ~ 10^8 C for Sgr A*. The second, induction mechanism concerns rotating Kerr black holes embedded in an external magnetic field, which leads to electric field generation due to the twisting of magnetic field lines. This electric field can be associated with the induced Wald charge, for which we calculate the upper limit of ~ 10^(15) C for Sgr A*. Although the maximum theoretical limit of ~ 10^(15) C is still 12 orders of magnitude smaller than the extremal charge of Sgr A*, we analyse a few astrophysical consequences of having a black hole with a small charge in the Galactic centre. Two most prominent ones are the effect on the X-ray bremsstrahlung profile and the effect on the position of the innermost stable circular orbit.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/EF16_027%2F0008521" target="_blank" >EF16_027/0008521: Podpora mezinárodní mobility výzkumných pracovníků na SU</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

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

Název statě ve sborníku

Journal of Physics: Conference Series. Volume 1258, Issue 1, 21 October 2019, Article number 012031. 1st Sharjah International Conference on Particle Physics, Astrophysics and Cosmology, FISICPAC 2018; University of SharjahSharjah; United Arab Emirates; 11 November 2018 through 13 November 2018; Code 153573

ISBN

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ISSN

1742-6588

e-ISSN

—

Počet stran výsledku

17

Strana od-do

„012031-1“-„012031-17“

Název nakladatele

Institute of Physics Publishing

Místo vydání

neuvedeno

Místo konání akce

University of Sharjah, United Arab Emirates

Datum konání akce

11. 11. 2018

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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