| Project/Area Number |
05640306
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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 | Niigata University |
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Principal Investigator |
TOMISAKA Kohji Niigata U.Fac.education Assoc.Professor, 教育学部, 助教授 (70183879)
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| Co-Investigator(Kenkyū-buntansha) |
HABE Asao Hokkaido U.Fac.Science Assoc.Professor, 理学部, 助教授 (90180926)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1993: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Supernova Remnants / Interstellar Magnetic Fields / Magnetohydrodynamics |
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| Research Abstract |
1. Evolutions of magnetized supernova remnants are studied with the ideal MHD simulation. Poloidal magnetic fields are taken into account and a two-dimensional axisymmetric MHD code is used.
2. (1) "Monotonic Scheme" (a kind of TVD schemes) and "Constrained Transport Scheme, " which conserves strictly the divergence of magnetic fields, are adopted.
(2) It is shown that the "Nested Grid" technique is applicable to the MHD simulations.
3. The effect of the magnetic fields becomes crucial in a late phase of supernova remnants.
(1) In the case of 5*10^<50> ergs of the explosion energy and 0.3cm^<-3> of the ambient density, the magnetic fields with B_0=5muG reduces the volume occupied with a hot gas to -20% of the volume expected for a nonmagnetic supernova remnant.
(2) The magnetic tension plays a role after -1 Myr has passed since the supernova explosion occurs. The supernova remnant contracts due to the magnetic tension.
4. This indicates that the volume fraction of hot interstellar matter seems much smaller than that suggested previously.
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