国际天球参考系

阐述了１９９８年１月４日起ＩＡＵ采用的天球参考系的定义，以及它与以往采用的光学天球参考架ＦＫ５的关系。介绍了国际天球参考系在射电波段的实现过程，其稳定性的维持方法和它与依巴谷星表之间的关系。重点描述了影响国际天球参考架稳定性的物理因素－河外射电源的结构及其变化，射电源喷流的视超光速现象和由银河系盘星和大质量致密晕的引力透镜效应引起的视自行等。

International Celestial Reference System

Since January 1, 1998 the international Celestial Reference System (ICRS) has been adoptedby IAU. In this paper, the definition of the ICRS, the relation between ICRS and FKS, whichis the previous optical celestical reference frame, are described. The procedure of the realizationof ICRS in the radio wavelength, the method of maintenance of ICRS and the linkage betweenvarious reference frames such as ICRS and Hipparcos Catalogue, ICRS and ephemeris DE200 arealso illtroduced. The influences of the physical characteristics of radio sources on the stabilityof international Celestial Reference Frame (ICRF) such as the structure and 'proper motion' ofextragalactic radio sources, superluminal phenomenon of the jet of radio source and the gravitational lensing due to the the disk stars and MACHOs in our Galaxy are emphasized. Finally,authors suggest some research subjects to be developed for the contribution of Chinese VLBInetwork to the mailltenance of extragalactic reference frame with sub-milliarcsecond accuracy.