Polarimetry and strong gravity effects from spots orbiting near a black hole

0567696 - ASÚ 2023 RIV SG eng C - Konferenční příspěvek (zahraniční konf.)
Karas, Vladimír - Dovčiak, Michal - Svoboda, Jiří - Zhang, Wenda - Matt, G. - Eckart, A. - Zajaček, M.
Polarimetry and strong gravity effects from spots orbiting near a black hole.
The Fifteenth Marcel Grossmann Meeting: On Recent Developments in Theoretical and Experimental General Relativity, Astrophysics, and Relativistic Field Theories. Singapore: World Scientific, 2022 - (Battistelli, E.; Jantzen, R.; Ruffini, R.), s. 220-224. ISBN 978-981-125-825-1.
[Marcel Grossmann Meeting on General Relativity /15./. Rome (IT), 01.07.2018-07.07.2018]
Grant CEP: GA MŠMT LTI17018
Institucionální podpora: RVO:67985815
Klíčová slova: black holes * gravitation * galactic center
Obor OECD: Astronomy (including astrophysics,space science)

We study the modulation of the observed radiation flux and the associated changes in the polarization degree and angle that are predicted by the orbiting spot model for flares from accreting black holes. The geometric shape of the emission region influences the resulting model lightcurves, namely, the emission region of a spiral shape can be distinguished from a simpler geometry of a small orbiting spot. We further explore this scheme for the observed flares from the supermassive black hole in the context of Galactic center (Sgr A*). Our code simulates the lightcurves for a wide range of parameters. The energy dependence of the changing degree and angle of polarization should allow us to discriminate between the cases of a rotating and a non-rotating black hole.
Trvalý link: https://hdl.handle.net/11104/0338933