甚么是类星体和活跃星系核？
科学家过去认为，这些微尘环是高度活跃星系的主要特征。
Scientists had thought that these rings were key features of such highly energetic galaxies.
它们的表现可以极端活跃星系（称为类星体）中心的大型黑洞作为参照。
They behave as scaled-down versions of much more massive black holes that are at the cores of extremely active galaxies, called quasars.
应用推荐