| Project/Area Number |
12640236
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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 | HIROSHIMA UNIVERSIlY |
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Principal Investigator |
KUSANO Kannya Hiroshima University, Graduate School of Associate, Professor, 大学院・先端物質科学技術研究科, 助教授 (70183796)
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| Co-Investigator(Kenkyū-buntansha) |
YOKOYAMA Takaaki University of Tokyo, School of Sciences, Associate Professor, 大学院・理学研究科, 助教授 (00311184)
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| Project Period (FY) |
2000 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2002: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2001: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2000: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | the Sun / flares / corona / MHD / simulation / reconnection / magnetic helicity / plasma / ヘリシティ / 太陽磁場 / 不安定性 |
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| Research Abstract |
This project was carried out aiming to reveal the physical mechanism of the solar coronal energetic activity in terms of the combination of the detail observation of solar magnetic field by vector magnetographs and the three-dimensional numerical simulations. The following important results are obtained. (1)We developed a new methodology, which enables the measurement of magnetic helicity flux across the photospheric surface. (2)We found a clear correlation between the magnetic helicity flux across the photosphere and the soft X-ray energy flux out of the solar corona. (3)We revealed that the reversal of magnetic shear activates the energy liberation of the solar coronal magnetic field. (4)Based on the results above, we proposed a new flare model called "Reversed-Shear Flare Model", and examined the validity of that using the three-dimensional numerical simulations. (5)We investigated the spatial correlation between the magnetic shear structure and the brightening in pre-flare phases, and revealed that the initial bright points were located at the shear inversion line, as the Reversed-Shear Flare Model predicted. These results demonstrate the hypothesis that the magnetic helicity flux across the photosphere can play a cause of the solar coronal activity. In particular, it should be noted that the Reversed-Shear Flare Model can explain several important features seen in observation of solar flares. However, the development of the three-dimensional simulation only using realistic data is not yet completed, and remains for future works.
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