2000 Fiscal Year Final Research Report Summary
Study of Gamma-ray Bursts by the Cooperation with the Satellites and the Ground Based Observatories
| Project/Area Number |
09640368
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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 |
素粒子・核・宇宙線
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| Research Institution | Miyazaki University |
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Principal Investigator |
YAMAUCHI Makoto Miyazaki University, Faculty of Engineering Assoc.Prof., 工学部, 助教授 (80264365)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIDA Atsumasa The Institute of Physical and Chemical Research, Cosmic Radiation Lab. Senior Research Scientist, 宇宙放射線研究室, 先任研究員 (80240274)
HATSUKADE Isamu Miyazaki University, Faculty of Engineering Assoc.Prof., 工学部, 助教授 (30221500)
TAKAGISHI Kunio Miyazaki University, Faculty of Engineering Prof., 工学部, 教授 (80041060)
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| Project Period (FY) |
1997 – 2000
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| Keywords | transient object / gamma-ray burst / satellite / observation |
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| Research Abstract |
We have developed two kinds of instrument whose prime purpose is observing the gamma-ray bursts. One is HETE-II (High Energy Transient Explorer II) satellite, the other is MAXI (Monitor of All sky X-ray Image) onboard international space station. HETE-II satellite was launched on October 9th 2000 and was successfully enterd into the orbit. We have prepared for launching this satellite since 1997. The design of the instrument was slightly changed to improve the detection efficiency and the background rejection efficiency than those of the former one which was failed to operate. Many kinds of environmental test or performance test were carried out.
For the duration of many test for initial performance after its launch, we have obtained in-orbit calibration data of detectors. Now we have started the normal observation. As of March 26th 2001, 20 candidates for gamma-ray burst were discoverd and 10 events among them were confirmed by other observations.
We have also constructed the optical follow-up observation system in cooperation with HETE-II satellite on the rooftop of the builing in Miyazaki university. When HETE-II discovers a gamma-ray burst, it sends the position information of gamma-ray burst to the ground. This information will be received by the computer through the internet soon. Then the conputer controls the system to start the follow-up observation using a small telescope. The obtained data by this system will be compared with one obtained previosly or the catalogued data. We found that we can detect automatically an unknown object brighter than 18th magnutude using the exposure about 10 seconds.
We have not only developed an observational system, but also analized the observational data obtained by japanese satellite. We found two knees in the x-ray spectrum of a gamma-ray burst. This means the possibility of spectral variability of the gamma-ray burst.
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