【摘要】 本文提出，原则上所有活动星系核都能产生喷流，但是星系核心区域介质的渗入可能使得一部分喷流被减速以至于消失。这为喷流只见于一部分活动星系的事实提供了一种可能解释，也可能是建立活动星系核结构统一模型的一个有意义的步骤。更多还原

【Abstract】 We suggest that in principle all active galactic nuclei are able to produce jets,and then show that the entrainment of medium in the region of galactic nuclei can possibly destroy some jets.This result can be used to explain why jets are observed only in a part of active galaxies.It may also be a meaningful step towards building a unified model of active galactic nuclei.更多还原