| Project/Area Number |
61460008
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Astronomy
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| Research Institution | Tokyo Astronomical Observatory, University of Tokyo |
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Principal Investigator |
KAI Keizo Tokyo Astronomical Observatory, University of Toky, Professor, 東京天文台, 教授 (70012846)
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| Co-Investigator(Kenkyū-buntansha) |
SEKIGUCHI Hideaki Tokyo Astronomical Observatory, University of Tokyo, Technical staff, 東京天文台, 教務技官 (40154645)
SHIOMI Yasuhiko Tokyo Astronomical Observatory, University of Tokyo, Assistant, 東京天文台, 助手 (00134627)
NAKAJIMA Hiroshi Tokyo Astronomical Observatory, University of Tokyo, Lecturer (Iye,Masanori), 東京天文台, 講師 (40012877)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥6,300,000 (Direct Cost: ¥6,300,000)
Fiscal Year 1987: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1986: ¥4,100,000 (Direct Cost: ¥4,100,000)
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| Keywords | Solar radio emission / High energy phenomena of the Sun / 偏波観測 / ミリ波電波 / 太陽高エネルギー電子 / ミリ波帯電波 |
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| Research Abstract |
(1) Objective
We have proposed a new method for estimating energy spectra of nonthermal electrons prroduced in solar flares, using radio observations of bursts at mm wavelengths: the frequency (wavelengt h) dependence of both flux and polarization. The method can be used also for estimating the pol arity and intensity of magnetic fiels in the radio emitting region. These quantities could not otherwise be determined.
(2) Result
The frequency dependence of both flux and posarization was obtained for flare-associated bursts from observations made at three different frequencies with the 17, 35 and 80 GHz polarimeters at Nobeyama. Comparing the measured frequency dependence with that calculated based on gyrosynchrotron theory for various distribution functions of energetic electrons, we have obtained the following result: Hte energy spectrum of nonthermal electrons responsible for mmemission can be wxpressed as a power-law distribution. However it was found that the power-law distribution is not consistent with that independently derived from X-ray observations on the thick-target model, which has been widely accepeted as the X-ray emission model. How to resolve this discrepancy is a problem to be investigated in future.
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