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Magnetic field and radius of the innermost stable circular orbit near super‐massive black holes in active galactic nuclei
Author(s) -
Piotrovich M. Yu.,
Gnedin Yu. N.,
Silant'ev N. A.,
Natsvlishvili T. M.,
Buliga S. D.
Publication year - 2015
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.201512213
Subject(s) - physics , circular orbit , astrophysics , magnetic field , radius , faraday effect , accretion (finance) , schwarzschild radius , orbit (dynamics) , scattering , black hole (networking) , polarization (electrochemistry) , optics , quantum mechanics , computer network , routing protocol , computer security , routing (electronic design automation) , computer science , engineering , link state routing protocol , aerospace engineering , chemistry
Magnetic fields in an accretion disk around the central black hole can modify the size of the innermost stable circular orbit (ISCO) and can produce a difference to the classical Novikov‐Thorne radius. We estimated the ISCO magnetic field strength from the polarimetric observations of the accretion‐disk radiation. This estimate is obtained taking into account the effect of the Faraday rotation of the polarization plane at the distance of the mean free path of photons between successive electron scattering events. We present the new method for estimating the ISCO radius in the accretion disk, i.e. in the nearest vicinity of a central black hole. Our estimates confirmed the Frolov, Shoom & Tzounis (2014) and Ranea‐Sandoval & Garcia (2015) conclusion that the magnetic field in the accretion disk decreases the size of the innermost stable circular orbit. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)