2003/05/31 by Ramesh Narayan, Igor V. Igumenshchev, I. V. Igumenshchev +2 · 725 citations
Physics and Astronomy · #Accretion (finance) #Accretion disc #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Flow (mathematics) #Magnetic field #Magnetohydrodynamics #Mechanics #Physics #Pulsars and Gravitational Waves Research #RADIUS #Rotational symmetry #astro-ph #gr-qc
paper · pdf · doi:10.1093/pasj/55.6.l69
published in Publications of the Astronomical Society of Japan 55(6), L69-L72 (Oxford University Press) · 4 pages, 2 figure, new refs added, in print in PASJ
arxiv created 2003/09/26 · openalex publication_date 2003/12/25 · arxiv updated 2015/06/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract We consider an accretion flow model originally proposed by Bisnovatyi-Kogan and Ruzmaikin (1974), which has been confirmed in recent 3D MHD simulations. In the model, the accreting gas drags in a strong poloidal magnetic field to the center such that the accumulated field disrupts the axisymmetric accretion flow at a relatively large radius. Inside the disruption radius, the gas accretes as discrete blobs or streams with a velocity much less than the free-fall velocity. Almost the entire rest mass energy of the gas is released as heat, radiation and mechanical/magnetic energy. Even for a non-rotating black hole, the efficiency of converting mass to energy is of order 50% or higher. The model is thus a practical analog of an idealized engine proposed by Geroch and Bekenstein.