Three-dimensional magneto-hydrodynamic simulations of the formation of the inner torus in black hole accretion flows: Brief Instructions for Users of the 'WORKSHOP' Style File
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Department of Physics and Astrophysics, Nagoya University
Department of Physics, Chiba University
出版者
宇宙航空研究開発機構
出版者（英）
Japan Aerospace Exploration Agency (JAXA)
雑誌名
宇宙航空研究開発機構特別資料:
雑誌名(英)
JAXA Special Publication: The Energetic Cosmos; from Suzaku to ASTRO-H
巻
JAXA-SP-09-008E
ページ
308 - 309
発行年
2010-02-26
会議概要（会議名, 開催地, 会期, 主催者等）（英）
The 3rd Suzaku international Conference "Energetic Cosmos : from Suzaku to ASTRO-H" (June 29-July 2, 2009. Grand Park Otaru Hotel), Otaru, Hokkaido Japan
抄録（英）
We present the results of formation of the inner torus in black hole accretion flows obtained from three dimensional magneto-hydrodynamic simulations. We focus on the dependence of numerical results on the gas temperature supplied from the outer region. General relativisitc effects are taken into account using the pseudo-Newtonian potential. We ignore the radiative cooling of the accreting gas. The initial state is a torus threaded by a weak azimuthal magnetic field. We found that mass accretion rate and the mass outflow rate strongly depend on the temperature of the initial torus. In the cool model, a constant angular momentum inner torus is formed around 4-8gamm(sub s) where gamm(sub s) is the Schwarzschild radius. This radius is near the maximum radius of the radial epyciclic frequency. This inner torus deforms itself from a circle to a crescent quasi-periodically. During this deformation, the mass accretion torus returns to a circular shape and starts the next cycle. The time interval of this deformation is caused by the magnetic dynamo activitis driven by MRI. When the magnetic energy released, magnetic pressure driven outflows blow from the inner torus. Power spectral density (PSD) of the time variation of the mass accretion rate in the coolo model has a low frequency peak around 10Hz when we assumed a 10 solar mass black hole. The PSD of the hot model is flat in 1-30Hz. The slope of the PSD in the cool model is steeper than than in the hot model in 30-100Hz.
内容記述（英）
Meeting sponsors: The University of Tokyo, The Institute of Physical and Chemical Research, The Japan Society for the Promotion of Science
Three-dimensional magneto-hydrodynamic simulations of the formation of the inner torus in black hole accretion flows: Brief Instructions for Users of the 'WORKSHOP' Style File
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