摘要
长时间以来被看作是典型致密双源之一的类星体４Ｃ３９．２５，其主要成分显示坦谱，且具有特殊的视超光速结构变化。根据在１８厘米波长新的ＶＬＢＩ及ＭＥＲＬＩＮ观测，可以认为该源是一个核－喷流类星体．喷流在毫角秒尺度上旋转了大约９０度，并是终向７９度的方向角延伸，喷流中包含了几个“节”及在其终点的一个热斑。预期在更高频率的亚毫角秒观测可以证实这样的结构，并对其核本身在１８厘米，甚至６厘米波长都几乎是不可见的作出解释．
The quasar 4C39.25 has been long considered u one of paradigms of .ompact double sources which shows flat spectrum and peculiarly superluminal structure variation. On the basis of new observations at 18 cm with both VLBI and MERLIN, the source can be supposed as a core-jet quasar.The jet,consisting of several knots and a hot spot at the end, turns over about 90 degree on scales of mas and finally elongates toward to PA = 79° . Further sub-mas-resolution observations at higher frequency are expected to confirm this suspect and to explain why the Core itself is almost invisible in VLBI observations at 18 and even at 3 cm wavelengths.
基金
国家自然科学基金
