1999 Fiscal Year Final Research Report Summary
ROLE OF THE TOROIDAL MAGNETIC FIELD FOR THE FORMATION OF STRUCTURE OF ASTRONOMICAL BOLDES
| Project/Area Number |
09680468
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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 |
プラズマ理工学
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| Research Institution | SHONAN INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
WASHIMI Haruichi SHONAN INSTITUTE OF TECHNOLOGY. FACULTY OF ENGINEERINGS. PROFESSOR, 工学部, 教授 (60023686)
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| Co-Investigator(Kenkyū-buntansha) |
MORI Masao UNIVERSITY OF TOKYO. FACULTY OF SCIENCES. JSPS RESEARCH FELLOW, 理学部, 学＊特別研究員
TANAKA Takashi COMMUNICATIONS RESEARCH LABORATORY. SPACE SCIENCE DIVISION. SENIOR SCIENTIST, 宇宙科学部, 主任研究員
SHIBATA Shinpei YAMAGAWA UNIVERSITY. FACULTY OF SCIENCES, 理学部, 助教授 (90187401)
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| Project Period (FY) |
1997 – 1999
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| Keywords | STRUCTURE OF ASTRONOMICAL BODIES / TOROIDAL MAGNETIC FIELD / ASTRO-PLASMA / COSMIC PLASMA / SUPERNOVA / HELIOSPHERE |
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| Research Abstract |
This project was aimed to make clear that the toroidal magnetic field plays an important role for the formation of the structure of astronomical bodies. Among many astronomical bodies, we expected that the 3-ring structure in the Supernova (SN) 1987A nebula, which was observed by Hubble Space Telescope (HST) recently, was an important one, because the 3-ring was expected to be formed by the magnetic pressure effect due to the toroidal magnetic field. We were also interested in the magnetic effect in the heliosphere.
For this sake, we have developed a 3-dimensional magnetohydrodynamic (MHD) computer scheme and a graphic system, and performed computer simulation for the SN 1987A and the helioshere extensively.
Our results are as followings : (1) The center ring in SN 1987A is formed by the magnetic pressure force due to the toroidal field from both sides of the northern and southern hemisphere, because the magnetic intensity is extremely weak around the equatorial region. (2) The outer rings in the middle latitude in both northern and southern hemisphere of SN 1987A is found to be formed by the cooperative effects due to the pollard magnetic pressure force and the high ram pressure of the stellar wind in the high latitudes. (3) By the above two results, we first succeeded in recreating the 3-ring structure in the SN 1987A nebula, which means that the important role of the toroidal magnetic field for the formation of the structure is made clear. (4) The MHD structure of the heliosphere was also obtained. It is found that a ditch-type dent structure on the equatorial plane of the magnetic neutral sheet on the termination shock surface is formed due to the magnetic pressure effect.
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