Japan-U. K. Collaboration in X-ray Astronomy Research with the Scientific Satellite "Ginga"

1991财年成为Ginga卫星的任务寿命终点，自1987年2月5日发射以来，Ginga卫星在轨道上停留了4年零9个月。Ginga的轨道持续衰减，直到1991年10月30日与卫星进行最后一次接触。据信，银河于11月1日左右重新进入大气层。在此情况下，两名日本科学家三次访问英国，两名英国科学家也三次访问日本。本财年的主要合作成果包括以下三项：（1）双方科学家在银河号任务生命最后阶段密切合作。特别是作为Ginga主要仪器的英日联合实验大面积比例计数器，经过详细校准，证明其性能在整个任务寿命期间保持恒定。（2）整个Ginga数据都存储在日本和英国，对全世界仍将具有宝贵的科学价值。因此，讨论建立适当的方案，将这些档案数据向公众，特别是其他国家的科学家开放。(3)对多个研究课题进行联合数据分析，并准备联合论文。主题包括宇宙X射线背景、活动星系核、X射线脉冲星、发射X射线的白矮星等。

The fiscal year of 1991 has become the end of mission life of the Ginga satellite, which stayed in the orbit for 4 years and 9 months since the launch on February 5 1987. The orbit of Ginga continued to decay, until October 30 1991 when the last contact was made with the satellite. It is believed that Ginga re-entered the atmosphere on November 1 or so. Under these circumstances, two scientists from Japan visited the United Kingdom on three occasions, and two UK scientists visited Japan on three occasions as well. Principal results of collaboration in the present fiscal year include the following three items.(1)The scientists from, both parties closely collaborated on the Ginga operation during the last phase of its mission life. In particular, the Large Area Proportional Counter, a UK-Japan joint experiment serving as the main instrument of Ginga, has been calibrated in detail to demonstrate that its performance stayed constant during the entire mission life.(2)The entire Ginga data are stored both in Japan and UK, and will continue to be of precious scientific valuable for the entire world. Discussion was therefore made to establish an appropriate scheme to make these archival data open to public, especially to scientists of other countries.(3)Joint data analysis was made on several research topics, followed by preparations of joint papers. The topics include cosmic X-ray background, active galactic nuclei, X-ray pulsars, X-ray emitting white dwarfs, and so on.