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。

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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。

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This morning we noticed that one of the many active galaxies in the Fermi sky had become extremely bright in gamma-rays.

早上，我们从费米伽马射线图中的众多活跃星系中观察到，其中一个星系的伽马射线变得极度明亮。

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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