They also didn't compare active galaxies to those with quiet black holes.

它们也没有把活动星系同那些黑洞活动相对平静的星系作比较。

youdao

PKS 1502+106, and PKS 0727-115 are active galaxies billions of light-years distant.

在我们的银河系之外：巨大的星系NGC 1275 位于离我们 2.33 亿光年远的英仙座星系团的中心，而3C 454.3 PKS1502+106 PKS 0727-115 是距离我们数十亿光年远的活跃星系团。

youdao

This scenario may explain why only 10% of active galaxies have radio jets, and how active galaxies evolve over time.

这种假设或许可以解释为什么活跃星系中只有10%存在喷流，以及它们如何持续演变。

youdao

Centaurus A is the closest of the "active galaxies", which are galaxies spewing out huge amounts of energy and light.

BBC: Hubble spies black hole gobbling galaxy

They did this by taking a peek at an astronomers' catalogue of 318 active galaxies located within 300m light years of Earth.

ECONOMIST: Cosmic rays: They came from outer space | The

Blazars are a special case of "active galaxies" - those whose supermassive black holes spray out great quantities of light across the whole electromagnetic spectrum as they feed on surrounding matter.

BBC: Blazar Markarian 421's flare-up is cosmic coincidence