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

1991财政年度已成为结束使命寿命的Ginga卫星，它停留在轨道4年零9个月以来，1987年2月5日发射。Ginga的轨道继续衰减，直到1991年10月30日最后一次与卫星联系。据信，Ginga于11月1日左右重新进入大气层。在这种情况下，两名日本科学家三次访问联合王国，两名英国科学家也三次访问日本。本财政年度的主要合作成果包括以下三个项目。（1）双方的科学家在Ginga号使命寿命的最后阶段就其作业进行了密切合作。特别是，对作为Ginga主要仪器的大面积比例计数器-一项联合王国和日本的联合实验-进行了详细的校准，以证明其性能在整个使命寿命期间保持不变。（2）整个Ginga数据都存储在日本和英国，并将继续为整个世界提供宝贵的科学价值。因此，讨论了建立一个适当的计划，使这些档案数据向公众，特别是其他国家的科学家开放。（3）对多个研究主题进行联合数据分析，并准备联合论文。内容包括宇宙X射线背景、活动星系核、X射线天体、X射线发射白色矮星等。

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.