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旋臂区域观察到了许多神秘的发光X射线源。通过对日本第四颗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”（ULX）是质量吸积黑洞（BH），可能具有相对较大的质量。本研究旨在加强这一新观点，我们分析了大量ULX的ASCA，Chandra和XMM-Newton档案数据，并获得了进一步的证据，它们实际上是中等质量的BH。使用斯巴鲁望远镜，我们检测到一个ULX的光学对应物，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。使用HETE-2航天器，我们探测到了一次强烈的伽马射线爆发GRB 030329，这导致全世界发现它与一颗必定产生BH的超新星有关。我们还成功地推导出一个统一的图像与各种质量的黑洞在非常高的吸积率。所有这些结果将进一步发展的第五次日本X射线使命朱雀，已成功地发射于2005年7月10日。我们为朱雀号上的硬X射线探测器（HXD）的开发做出了贡献。为了进一步推动朱雀号HXD以外的ULX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条探测器的傅里叶合成成像仪，并在实验室实验中验证了其性能。我们的成就还包括成功开发了替代CeTe的堆叠式薄板蒸发器，以及对新的多晶蒸发器进行了评估。

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.