Grant-in-Aid for international Scientific Research
|Allocation Type||Single-year Grants|
|Research Institution||National Astronomical Observatory|
WATANABE Tetsuya Solar Physics Division, National Astron.Soc.Japan Associate Professor, 太陽物理学研究系, 助教授 (60134631)
BENTLEY R.D. Mullard Space Science Laboratory, Univeristy College London, 研究員
CULHANE J.L. Mullard Space Science Laboratory, University College London, 教授
MASUDA Satoshi Solar Terrestrial Environment Laboratory, Magoya University, 太陽地球環境研究所, 助手 (10262916)
HARA Hirohisa Solar Physics Division, National Astronomical Observatory, 太陽物理学研究系, 助手 (20270457)
SAKAO Taro Solar Physics Division, National Astronomical Observatory, 太陽物理学研究系, 助手 (00225781)
TSUNETA Saku Institute of Astronomy, University of Tokyo, 理学部, 助教授 (50188603)
SHIBATA Kazunari Solar Physics Division, National Astronomical Observatory, 太陽物理学研究系, 助教授 (70144178)
SAKURAI Takashi Solar Physics Division, National Astronomical Observatory, 太陽物理学研究系, 教授 (40114491)
KOSUGI Takeo Radio Astronomy Division, National Astronomical Observatory, 電波天文学研究系, 教授 (70107473)
OGAWARA Yoshiaki High Energy Physics Division, Institute of Astronautical Scineces, 宇宙圏研究系, 教授 (80013671)
UCHIDA Yutaka Department of Physics, Tokyo University of Science, 理学部, 教授 (90012814)
BENTLEY R.D. Mullard Space Science Laboratory Univers, 研究員
平山 淳 国立天文台, 太陽物理学研究系, 教授 (20012841)
|Project Period (FY)
1994 – 1995
Completed(Fiscal Year 1995)
|Budget Amount *help
¥7,600,000 (Direct Cost : ¥7,600,000)
Fiscal Year 1995 : ¥3,500,000 (Direct Cost : ¥3,500,000)
Fiscal Year 1994 : ¥4,100,000 (Direct Cost : ¥4,100,000)
|Keywords||Solar Flares / Solar High Energy Phenomena / Soft X-ry High Resolution Observation / Bragg Spectrometer / 科学衛星「ようこう」|
The sun observing satellite YOHKOH has been successfully operated for five years from the previous activity maximum and throughout the declining phase.All the scientific instruments onboard has been in good condition and the soft X-ray instruments can observe the quiet sun even at its minimum.
Investigating the whole set of data, the keyword of "magnetic reconnection" has been emerged as a fundamental process for producing high temperature plasmas in the corona.Loop-top hard X-ray sources newly found by Yohkoh show consistency with the "magnetic reconnection scenario." Characteristic of nonthermal line broadenings seen in helium-like sulphur lines were systematically investigated.The locations of hot plasmas at the time of the line broadening maximum were either footpoints or loop top of flaring loops.
Statistical studies of X-ray jets were also completed and they were mostly found in active regions with mixed magnetic polarity and strongly associated with emerging-flux regions.The interaction of emerged magnetic fields with pre-existing coronal field causes X-ray jets.Correspondence with micro-flares also suggests that the both phenomena come from the same mechanism.
On the other hand, some evidence also appeared for the mechanism of basic coronal heating was something other than "magnetic reconnection."
The Yohkoh dataset was compiled for nearly half of the solar cycle, with which studies of solar cycle and solar dynamo mechanisms will be done in future.The SoHO satellite launched in December 1995 will now station at the Lagrangean point and start its observations.Joint observations and collaborative studies with SoHO will be highly encouraged for the first space observations in the rising phase of the solar activity.