| Project/Area Number |
12640240
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Astronomy
|
|---|
| Research Institution | Institute of Space and Astronautical Science |
|---|
Principal Investigator |
SAKAO Taro Institute of Space and Astronautical Science (ISAS), Research Division for Basic Space Science, Associate Professor, 共通基礎研究系, 助教授 (00225781)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NAGATA Shin'ichi ISAS, Research Divison for Basic Space Science, Research Assistant, 共通基礎研究系, COE研究員
MATSUZAKI Kei-ichi ISAS, Center for Planning and Information Systems, Research Associate, 宇宙科学企画情報解析センター, 助手 (20321565)
KOSUGI Takeo ISAS, Research Division for Basic Space Science, Professor, 共通基礎研究系, 教授 (70107473)
KANO Ryouhei National Astronomical Observatory, Solar Physics Division, Research Associate, 太陽物理学研究系, 助手 (70321586)
MASUDA Satoshi Nagoya University, Solar-Terrestrial Environment Laboratory, Associate Professor, 太陽地球環境研究所, 助教授 (10262916)
|
|---|
| Project Period (FY) |
2000 – 2001
|
| Project Status |
Completed (Fiscal Year 2001)
|
| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2001: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
|
|---|
| Keywords | Solar Flares / Particle Acceleration / Hard X-ray Radiation / Magnetic Field Structure |
|---|
| Research Abstract |
By studying temporal evolution of solar flare hard X-ray footpoint sources with the Hard X-ray Telescope (HXT) aboard Yohkoh satellite, we have investigated magnetic field structure associated with flares and particle acceleration process(es). Amongst flares observed, a large flare which commenced on 14 July, 2000 has provided a unique opportunity to study hard X-ray footpoint sources in great detail. Analysis of this flare revealed a striking result that non-thermal (above 30 keV) footpoint sources show a pair of thin elongated ribbons which reminds one the so-called "two-ribbon structure" in H-alpha observations. This suggests that magnetic arcade structure, not just a single loop, should take part in solar flare energy release. Detailed analysis on the footpoint sources has indicated that magnetic shear decreases as the flare progresses, and that the sources tend to show harder spectra towards outer edges. These observational findings are expected to provide important clues for investigating particle acceleration mechanisms in flares. In addition to analyses of hard X-ray footpoint sources, theoretical studies, stimulated with the analyses, have been in progress with an attempt to understand solar flare energy release in the framework of 3-dimensional magnetic reconnection.
|
