Verifying the Black Hole Interpretation of Ultra Luminous Cosmic X-ray Sources

二十多年来，宇宙x射线研究人员在附近螺旋星系的臂区观察到许多神秘的发光x射线源。通过日本第四颗x射线天文卫星ASCA（1993-2001）的观测，我们得出了一个新的假设，即这些“超亮致密x射线源”（ULXs）是质量吸积黑洞（BHs），可能具有相对较大的质量。本研究旨在加强这一新的观点。我们分析了ASCA、钱德拉和xmm -牛顿大量ulx的档案数据，并获得了进一步的证据，证明它们实际上是中等质量的黑洞。利用斯巴鲁望远镜，我们探测到了一个超光速x射线的光学对应体，并获得了一个变化的暗示，这表明伴星（x射线发射器）相当大。利用HETE-2宇宙飞船，我们探测到了一个强烈的伽马射线暴GRB030329，这导致了全世界范围内的发现，即它与一颗一定产生了黑洞的超新星有关。我们还成功地推导出在非常高的吸积速率下具有不同质量的黑洞的统一图像。所有这些结果都将由2005年7月10日成功发射的日本第五次x射线任务“朱雀”进一步发展。我们为朱雀号上的硬x射线探测器（HXD）的开发做出了贡献。为了进一步推动ULX在Suzaku HXD之外的研究，我们需要具有成像能力的硬x射线探测器，因此，我们开发了使用调制准直器和CeTe条带探测器的傅里叶合成成像仪，并在实验室实验中验证了它们的性能。我们的成就还包括成功开发了堆叠薄板闪烁体代替CeTe，以及评估了新的多晶闪烁体。

Over two decades, cosmic X-ray investigators have observed a number of mysterious luminous X-ray sources in arm regions of nearby spiral galaxies. Through observations with the 4th Japanese X-ray astronomy satellite ASCA (1993-2001), we have arrived at a novel hypothesis that these "ultra-luminous compact X-ray sources" (ULXs) are mass-accreting black holes (BHs), possibly with relatively large masses. The present research aims at strengthening this novel view.We have analyzed archival ASCA, Chandra, and XMM-Newton data of a large number of ULXs, and obtained further pieces of evidence that they are actually intermediate mass BHs. Using the Subaru telescope, we detected an optical counterpart to one ULX, and obtained a hint of variability which suggests that the companion (the X-ray emitter) is fairly massive. Using the HETE-2 spacecraft, we have detected an intense gamma-ray burst GRB030329, leading to the world-wide discovery that it is associated with a hyper-nova that must have produced a BH. We also succeeded in deducing a unified picture on BHs with various masses under very high accretion rates.All these results are to be further developed by the 5th Japanese X-ray mission Suzaku, which has been launched successfully on 2005 July 10. We have contributed to the development of the Hard X-ray Detector (HXD) onboard Suzaku.To further promote the ULX investigation beyond the Suzaku HXD, we need hard X-ray detectors with imaging capability, Accordingly, we have developed Fourier-synthesis imagers using modulation collimators and CeTe strip detectors, and verified their performance in laboratory experiments. Our achievements further include the successful development of stacked thin-plate scintillators in place of CeTe, and the evaluation of new poly-crystalline scintillators.