Details
| Original language | English |
|---|---|
| Article number | 012031 |
| Number of pages | 17 |
| Journal | Journal of Physics: Conference Series |
| Volume | 1258 |
| Issue number | 1 |
| Publication status | Published - 21 Oct 2019 |
| Externally published | Yes |
| Event | 1st Sharjah International Conference on Particle Physics, Astrophysics and Cosmology, FISICPAC 2018 - Sharjah, United Arab Emirates Duration: 11 Nov 2018 → 13 Nov 2018 |
Abstract
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 ∼ 108 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 ∼ 1015 C for Sgr A∗. Although the maximum theoretical limit of ∼ 1015 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.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- General Physics and Astronomy
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In: Journal of Physics: Conference Series, Vol. 1258, No. 1, 012031, 21.10.2019.
Research output: Contribution to journal › Conference article › Research › peer review
}
TY - JOUR
T1 - Constraining the charge of the Galactic centre black hole
AU - Zajaček, Michal
AU - Tursunov, Arman
AU - Eckart, Andreas
AU - Britzen, Silke
AU - Hackmann, Eva
AU - Karas, Vladimír
AU - Stuchlík, Zdeněk
AU - Czerny, Bozena
AU - Zensus, J. Anton
N1 - Publisher Copyright: © 2019 IOP Publishing Ltd. All rights reserved.
PY - 2019/10/21
Y1 - 2019/10/21
N2 - 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 ∼ 108 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 ∼ 1015 C for Sgr A∗. Although the maximum theoretical limit of ∼ 1015 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.
AB - 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 ∼ 108 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 ∼ 1015 C for Sgr A∗. Although the maximum theoretical limit of ∼ 1015 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.
UR - http://www.scopus.com/inward/record.url?scp=85074788159&partnerID=8YFLogxK
U2 - 10.48550/arXiv.1812.03574
DO - 10.48550/arXiv.1812.03574
M3 - Conference article
AN - SCOPUS:85074788159
VL - 1258
JO - Journal of Physics: Conference Series
JF - Journal of Physics: Conference Series
SN - 1742-6588
IS - 1
M1 - 012031
T2 - 1st Sharjah International Conference on Particle Physics, Astrophysics and Cosmology, FISICPAC 2018
Y2 - 11 November 2018 through 13 November 2018
ER -