Investigation of X-ray Objects with Astro-D and ROSAT

日本国际天文研究所的第四颗x射线天文卫星ASCA （ASTRO-D）于1993年2月发射。ASCA是一个x射线天文台，首次能够在0.5-10 keV的宽能量范围内同时进行成像和光谱观测。鉴于德国马克斯-普朗克研究所的x射线天文卫星ROSAT于1990年6月发射。ROSAT也是一个x射线天文台，其特点是具有出色的成像能力，尽管它的能量带比ASCA更窄。ASCA具有比ROSAT高得多的光谱能力，而ROSAT具有比ASCA更精细的成像能力和更高的源探测灵敏度。两个天文台确实是互补的。日本和德国科学家在同步观测、x射线望远镜的交叉校准、数据交换、分析软件开发、sc讨论等方面进行了广泛的合作，更多的科学成果，向国际社会展示结果，未来仪器的发展等等。ASCA仪器覆盖了等离子体诊断最重要的能量带，因为所有的k线和从氧到铁在不同电离阶段的k吸收边都在这个波段内。ASCA的CCD摄像机可以单独分辨所有主要线路。从谱线能量的多普勒频移可以明显地测量到1000 km/s以上数量级的等离子体运动。ASCA的这些功能可以诊断中子星和黑洞等致密物体周围的吸积物质。另一方面，ROSAT望远镜提供了每个x射线源的精确位置，使我们能够识别光学上已知的x射线源。利用ROSAT获得的高分辨率空间信息也为研究超新星残骸、星系和星系团中的扩展等离子体提供了有力的手段。结合这两个天文台的这些特点，已经获得了一些显著的科学成果，并在许多科学论文中得到了证明。这种合作研究应该在未来继续下去。少

ASCA (ASTRO-D), the fourth X-ray astonomy satellite of ISAS,Japan, was launched in February, 1993. ASCA is an X-ray astronomy observatory which is, for the first time, capable of performing imaging and spectroscopic observations simultaneously over a wide energy range 0.5-10 keV.Whereas, ROSAT,the X-ray astronomy satellite of the Max-Planck Institute, Germany, was launched in June, 1990. ROSAT is also an X-ray astronomy observatory which is characterized by its excellent imaging capability, although it is limited to narrower energy bands than ASCA.ASCA has much higher spectral capability than ROSAT,while ROSAT has much finer imaging capability and higher source detection sensitivity that ASCA.Both observatories are really complimetary to each other.An extensive collaboration between Japanese and German scientists has been carried out in performing simultaneous observations, cross-calibrations of the X-ray telescopes, exchanging the data, developping analysis software, discussing the sc … More ientific yields, presenting the results to international communities, future development of instruments and so on.The ASCA instruments cover the most important energy band for plasma diagnostics, because all the K-lines and the K-absorption edges from oxygen through iron at various ionization stages lie within this band. The CCD camera of ASCA can resolve all major lines individually. Motion of plasma of the order or greater than 1000 km/s can be measured significantly from Doppler shift of the line energies. These capabilities of ASCA allow diagnostics of accreting matter around such compact objeots as neutron stars and black holes. On the other hand, the ROSAT telescope provides an accurate position of each X-ray sources and enables us to indentify the X-ray sources with optically known sources. The highly resolved spatial information with ROSAT also provides powerful means for the investigations of extended plasmas in supernova remnants, galaxies, and clusters of galaxies. Combining these characteristics of the two observatories, several remarkable scientific results have already been obtained and shown in many scientific papers. This collaborative study should be kept continuing in future. Less