Restrictions on the Parameters of Black Hole and Plasma in the Vicinity of the Source Sagittarius A

• Published in: Astronomy reports Vol. 65; no. 2; pp. 110 - 125
• Main Author: Chernov, S. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-02-2021; Springer Nature B.V
• Subjects: Astronomy; Constrictions; Deposition; Electron energy; Energy dissipation; Flux density; Galaxies; Magnetic fields; Mathematical models; Observations and Techniques; Parameter estimation; Physics; Physics and Astronomy; Plasma; Protons; Radiation; Radio range; Rotation; Supermassive black holes; Synchrotron radiation; Synchrotrons
• ISSN: 1063-7729; 1562-6881
• DOI: 10.1134/S1063772921020013

Estimates for the parameters of accretion plasma flows and the central black hole by comparing the MHD model numerical calculations with observations for the center of our Galaxy Sagittarius
A*
in the radio range are obtained. The accretion flow was modeled in terms of the distribution of a toroidal two-temperature electron-proton plasma. It is assumed that protons are heated due to viscous dissipation effects, and electrons lose energy due to synchrotron radiation. It is considered that the Coulomb interactions between protons and electrons are ineffective. Based on a comparison with observations of the spectral flux density and polarization (linear and circular) for a supermassive black hole in the source Sagittarius
A
*, the following restrictions were obtained: the rotation parameter (spin) of the black hole is equal to
, the electron temperature is a fraction
of the proton temperature, the observer is located at an angle
to the rotation axis of the black hole, and the accretion rate is much less than the Eddington limit
. It was not possible to obtain restrictions on the magnetic field due to the small sample in the plasma parameter
.