Structure and Evolution of Clusters of Galaxies by X-Ray Observations

(1)星系团观测分析了ASCA和XMM-Newton观测到的近300个星系团的x射线图像和空间图，研究了它们的结构和演化。推导了0.7 ~ 10kev两个能带的强度比和铁谱与连续体分量的比值，构建了整个簇上铁谱的硬度比和等效宽度图。根据这些图，通过光谱分析获得了选定区域的等离子体温度和铁丰度。结果表明，星系团合并会产生巨大的Mpc尺度的热区域，而星系团对星系团主体的引力落入会在星系团外围形成斑块状的几kpc尺度的冷区域。然而，铁丰度的分布与等离子体温度的分布不一致。这是有待进一步调查的问题。(2)硬x射线望远镜研制：通过建立量产体系，构建了Pt/C多层超镜硬x射线望远镜。在名古屋大学和NASA/GSFC （InFOCμS项目）的合作下，该望远镜通过气球飞行成功地进行了Cyg X-1的首次硬x射线成像观测。所有仪器都安全回收，因此第二次飞行定于2003年9月进行。为了提高望远镜的质量和多层超反射镜的制作效率，采用玻璃心轴上多层超反射镜直接复制的方法制作了多层超反射镜。我们还开发了成像硬x射线探测器，以完整地组装我们实验室的望远镜系统。

(1) Ovservatios of clusters of galaxiesX-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 telescopeA 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.