| Project/Area Number |
16540213
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Astronomy
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| Research Institution | The University of Tokyo |
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Principal Investigator |
SHIGEYAMA Toshikazu The University of Tokyo, Graduate School of ScienceUniversity of Tokyo, Associate Professor (70211951)
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| Project Period (FY) |
2004 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥2,250,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥150,000)
Fiscal Year 2007: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2006: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2005: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2004: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | supernovae / light element production / self-similar solutions / collisionless plasmas / stationary solutions / プラズマ / 無衝突系 / 特殊相対論 / 衝撃波 / 金属欠乏星 / 銀河の化学進化 / 相対論 |
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| Research Abstract |
Phenomena associated with supernova explosions of massive stars with stripped envelope like WolfRayet stars are investigated from three aspects. 1. Numerical calculations using a relativistic hydrodynamics code were performed to investigate the acceleration of the outer most envelopes of massive stars exposing their C-O cores. The subsequent interaction of the accelerated C and O (He) with H and He (N) is also investigated to estimate the amount of light elements (Li, Be, and B) through spallation (and/or fusion) reactions. It has been shown that these processes can be realized in a rapidly rotating star even in the early stages of a galaxy and enhance the contents of these elements in the circumstellar matter around the star This indicates that stars with large amount of the light elements could form in an infant galaxy 2. Two self similar solutions describing the passage of an ultra-relativistic shock through the stellar surface and the subsequent hydrodynamical interactions with the circumstellar matter are discovered in the plane parallel geometry The latter solution is extended to include the effect of the spherical shape of the stellar surface. A comparison with results from numerical calculation is made to estimate the validity of this extention. 3. We have investigated electromagnetic interactions of two plasmas with counter streams by numerical calculations for Vlasov-Maxwell systems with 2-D in real-space and 3-D in momentum space. We have observed the formation of filamentary structure, amplifying magnetic fields, the merging of these filaments, and the associated change of the configuration of magnetic fields. Because the intermediate states appear as quasi- stationary state, we have developed an analytical expression for this state expanding the deviation of the distribution function from the Maxwell-Boltzmann distribution into the Hermite polynomial systems.
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