1997 Fiscal Year Final Research Report Summary
X-ray study for the Unified Seyfert Model and evolution of AGN
| Project/Area Number |
07454040
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | KYOTO UNIVERSITY |
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Principal Investigator |
AWAKI Hisamitsu Kyoto University Physics Reseach Associate, 大学院・理学研究科, 助手 (30252414)
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| Co-Investigator(Kenkyū-buntansha) |
KOYAMA Katsuji Kyoto University Physics Proffesor, 大学院・理学研究科, 教授 (10092206)
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| Project Period (FY) |
1995 – 1997
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| Keywords | X-ray / AGN / Unified Model / evolution |
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| Research Abstract |
Our motivations for this research are to examine the Unified Seyfert model and to reveal an evolutional link between Seyfert galaxies and Starburst galaxies.
1)examination of the Unified Seyfertmodel
In the unified Seyfert model, Seyfert 2 galaxies have the same nuclei as those of Seyfert 1 galaxies, and the nuclei are obscured by surrounding matter. The Japanese X-ray sattelite Ginga found several Seyfert 2 galaxies which X-ray spectra could be well explained by the mode. However, it is still unclear whether the model can be applied for all Seyfert 2 galaxies. We made non X-ray bias sample in order to resolve this problem, then we observed them with the Japanese X-ray satellite ASCA.We found obscured nuclei from all of our targets, and their luminosities were similar to those of Seyfer 1 galaxies as predicted by the unified Seyfert model. We studied the disctribution of column density of the obscuring matter, then found that Seyfert 2 galaxies have similar clumn density of 10^<23> cm^<-2> each other.
2)evolution of AGN
An evolutional scenario of active galactic nucleus were proposed by Sanders. In order to examine this scenario, we observed Seyfert 2 galaxied with weak activity and composite type of Seyfert and starburst activities with ASCA.We found that the spectral property was quite similar to that of starburst galaxy or LINER.Recent optical observations suggests that these galaxies except for NGC1667, should be classified into LINER.Our observations and the optical identification indicate that previous classification were not complete.
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