| Project/Area Number |
04640268
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Astronomy
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| Research Institution | Nagoya University |
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Principal Investigator |
TOMIMATSU Akira Nagoya University, Department of physics, Professor, 理学部, 教授 (10034612)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1993: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1992: ¥700,000 (Direct Cost: ¥700,000)
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| Keywords | Rotating Black Hole / Active Galaxies / Plasma Flows / MHD Waves / X-ray Radiation |
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| Research Abstract |
Observational studies of active galactic nuclei suggest the existence of a massive black hole in the central region. In this research the astrophysical activities, such as jet formation and X-ray radiation, have been investigated in terms of a model of the black hole magnetosphere, by using the general ralativistic magnetohydrodynamic (MHD) equations. The approach is to consider the following three magnetospheric regions and to analyze plasma flows and magnetic field-line configurations.
1. The inner ingoing-wind region with accretion onto black hole : For magnetically dominated winds near the black hole, the interaction between magnetic field and plasma particles transporting energy and angular momentum is found to work very effectively. Then it is shown that the generation of MHD waves highly disturbs the ingoing motion of plasma, and the collimated propagation towards therotation axis occurs as a trigger of jet-like outgoing winds.
2. The outer outgoing-wind region extending to large distances : The magnetic self-collimating action of field lines is studied to estimate characteristicscales of the jet structure of relativistic outgoing winds and to give a boundary condition on the equatorial plane. The conclusion is that any observed jets should not have too high Lorentz factors.
3. The particle creation region which is a boundary layr between ingoingand outgoing winds : The Joule dissipation in a thin shell with a large current density is proposed as a mechanism of steady supply of plasma particles into the magnetosphere. This idea is verified, by showing the production of ingoing and outgoing mass fluxes with a heat flux which is converted into X-ray radiation. Anunified treatment of the three different regions to relate the inner magnetospheric structure to the outer one through the particle creation mechanism remains in future works.
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