【摘要】 从观测事实出发,我们给出了活动星系核的定义,阐述了活动星系核的细致分类,探讨了影响活动星系核观测特征的各种因素,以及它的家族成员之间的相互关系。最后,我们指出活动星系核的现象是极普遍的。更多还原

【Abstract】 From observational facts, this review paper offers a definition of AGNs, elaborates detail classification of AGNs, goes further into a lot of factors interfering with observational characters of AGNs and some interrelationships between various iamily members.Finally, we point out that AGN phenomena at low energy levels are extremely common.更多还原