2002 Fiscal Year Final Research Report Summary
Structure and Evolution of Clusters of Galaxies by X-Ray Observations
| Project/Area Number |
07102007
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| Research Category |
Grant-in-Aid for Specially Promoted Research
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| Allocation Type | Single-year Grants |
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| Review Section |
Physics
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| Research Institution | Nagoya University |
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Principal Investigator |
YAMASHITA Koujun Dept. of Physics, Professor, 大学院・理学研究科, 教授 (80022622)
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| Co-Investigator(Kenkyū-buntansha) |
NAMBA Yoshiharu Faculty of Engineering, Chubu University, Professor, 工学部, 教授 (40029129)
KUNIEDA Hideyo Institute of Space and Astronautical Science, Professor, 教授 (00126856)
TAWARA Yuzuru Dept. of Physics, Associate Professor, 大学院・理学研究科, 助教授 (10135296)
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| Project Period (FY) |
1999 – 2002
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| Keywords | Cluster of galaxies / X-ray spectrum / Plasma temperature / Iron emission lines / Elemental abundance / Hard X-ray telescope / Multilayer supermirror / Balloon observation |
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| Research Abstract |
(1) Ovservatios of clusters of galaxies
X-ray images and spactra of nearly 300 clusters of galaxies observed by ASCA and XMM-Newton were analyzed to investigate their structure and evolution. Intensity ratios of two energy bands in 0.7-10keV and iron lines to continuum component are derived to construct maps of hardness ratio and equivalent width of iron lines over a whole cluster. Referring to these maps, plasma temperature and iron abundance are obtained in selected regions by spectral analysis. It turned out that cluster merging would produce large hot regions with Mpc scale, whereas gravitational infalling of group of galaxies to the main body of clusters forms patchy cool regions with a few kpc scale in the ouetr envelope of a cluster. However distribution of iron abundance could not coincide to that of plasmatemperature. This is the problem to be investigated further.
(2) Development of hard X-ray telescope
A Pt/C multilayer supermirror hard X-ray telescope was constructed by establishing the mass production system. The first hard X-ray imaging observation of Cyg X-1 was successfully carried out by a balloon flight on board this telescope under the collaboration of Nagoya University and NASA/GSFC (InFOCμS project). All instruments were safely recovered, so that the second flight is scheduleed on September, 2003. In order to improve the quality of telescopes and production efficiency of multilayer supermirrors, multilayer replica mirrors are fablicated by the direct replication method of multilayers on glass mandrel to thin Al-foil substrates. We also developed imaging hard X-ray detectors to completely assemble the telescope system in our laboratory.
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