A cosmic behemoth seems to have escaped its home galaxy. A new image from the Hubble Space Telescope shows a trail of stars leading away from a galaxy nearly 11 billion light years away, which may indicate a supermassive black hole that has been flung away and is leaving bursts of star formation in its wake.

一个宇宙庞然大物似乎已经逃离了它的母星系。哈勃太空望远镜拍摄的一张新图像显示，一条从一个近110亿光年外的星系中走出来的恒星轨迹，这可能表明有一个超大质量的黑洞被甩出，并在它的尾迹上留下了恒星形成的爆发。

“There’s this weird straight line that points to the heart of this little galaxy, and we’ve never seen something like that before,” says Pieter van Dokkum at Yale University, who spotted this oddity. “It looks to the eye like something shot out of that galaxy, and now something very massive is barrelling through space at incredible velocities.”

“有一条奇怪的直线指向这个小星系的中心，我们以前从未见过这样的东西，”这个奇怪现象的发现者——耶鲁大学的Pieter van Dokkum说，“看上去，它就像从那个星系中射出的东西，现在，一个非常巨大的东西正以令人难以置信的速度在太空中飞驰。”

It is most likely that the massive object is a supermassive black hole that once resided at the centre of the galaxy. At the tip of the trail, van Dokkum and his colleagues found a bright knot of ionised oxygen, indicating that the black hole is slamming into the gas around it as it hurtles away at speeds around 1600 kilometres per second. The line of stars is more than 200,000 light years long, which means the black hole left its galaxy around 40 million years ago.

这个大质量物体很可能是一个超大质量的黑洞，它曾经位于星系的中心。在黑洞尾迹的末端，他和同事们发现了一个明亮的电离氧结节，表明黑洞在以每秒1600公里的速度飞驰的同时，正在与周围的气体相撞。这条恒星线超过20万光年长，这意味着黑洞大约在4000万年前离开了它的星系。

The most likely cause for its exodus is interactions between several different galaxies, a common process that was theorised to result in rogue supermassive black holes decades ago – a prediction that may finally be confirmed. When two galaxies merge, their supermassive black holes are thought to sink to the centre of the new, larger galaxy and orbit one another. But if a third galaxy comes into the picture, it could disrupt that orbit and fling one, or even all, of the black holes away into intergalactic space.

它的出走最有可能的原因是几个不同星系之间的相互作用，这是几十年前理论上导致流氓超大质量黑洞的常见过程——这一预测可能最终会得到证实。按之前的理论，当两个星系合并时，它们的超大质量黑洞会下沉到新的、更大的星系的中心，并相互环绕。但如果第三个星系出现，可能会扰乱轨道，将一个甚至所有黑洞抛向星系间空间。