天体物理学家通过监听碰撞产生的电磁回波，对中子星碰撞的情况有了更好的了解。克里斯托弗•因塔利亚塔报道。

撰文\播音：克里斯托弗·因塔利亚塔（Christopher Intagliata）

翻译：邱燕宁

审校：许楠

Last year, astronomers observed two neutron stars collide—a crash transmitted in gravitational waves to detectors here on Earth. Represented in sound, you can hear a small upwards sweep in frequency, in the data, if you listen closely. 

去年，天文学家观测到两颗中子星相撞——一种以引力波形式传送到地球上探测器的碰撞。如果你仔细听，你可以在数据中听到一个小的升阶频率。

<

<<片段：LIGO 中子星合并>>

Several seconds later, the first waves of electromagnetic radiation arrived here on Earth - the first time a collision has been detected by both light and gravitational waves. And it's in studying the electromagnetic echoes of the collision that astrophysicists have gotten a far better glimpse of what really happened after those binary neutron stars merged, 130 million light-years away. 

几秒钟后，第一波电磁辐射到达地球，这是第一次用光波和引力波探测到的碰撞。正是在研究碰撞的电磁回声时，天体物理学家们才得以更清楚地看到，在1.3亿光年之外，这两颗中子星合并后究竟发生了什么。

"Oh yeah, absolutely, so it gives us an understanding of basically all the nitty gritty of what's going on after the merger takes place." Kunal Mooley, an astrophysicist at Caltech.

“哦，是的，当然了，所以它让我们基本上了解了合并后发生的所有细节。” 加州理工学院的天体物理学家库农·莫里（Kunal Mooley）说。

First, he says, the stars collided <

首先，他说，这两颗恒星相撞，创造了一个巨大的，黑色黑洞状的物体，开始吸收撞击后留下的富含中子的宇宙碎片。但它的胃口（能力）有限。

"It cannot eat all of it, so some bit of it basically escapes." Those escaping leftovers spewed outward into space, as a powerful jet. But along the way, Mooley says, the jet appears to have interacted with that cloud of neutron-rich material, blowing up a sort of cocoon within the debris floating around the collision. Until finally, the jet burst out and slammed into interstellar space… releasing yet more radiation we could detect here on Earth. 

“因为它不能吸收所有的碎片，所以一些碎片会流失掉。”那些逃逸出来的剩余物向外喷射到太空，就像一架强大的喷气式飞机。但在此过程中，莫里说，喷射物似乎会与富含中子物质的云团相互作用，在碰撞周围漂浮的碎片中炸开了一个茧状结构。直到最后，喷气机爆炸并撞向星际空间，释放出更多我们在地球上可以探测到的辐射。

The full play by play is in the journal Nature. [K. P. Mooley et al., Superluminal motion of a relativistic jet in the neutron-star merger GW170817]

《自然》杂志上刊登了全部过程。

In this case, Mooley says, we were lucky to spot the event—the narrow jet was pointed close to Earth. But these collisions could be happening all the time, just that their jets point in directions hard to detect from Earth. But maybe, he says, astronomers can now look for those 'cocoons' as an alternate way to study these colossal bits of cosmic wreckage. 

在这种情况下，莫里说，我们很幸运的发现了这个事件——狭窄的射流指向了地球附近。但这些碰撞可能一直在发生，只是它们的喷射指向地球难以探测的方向。但他说，也许天文学家现在可以寻找这些“茧”，作为研究这些巨大的宇宙残骸的另一种方式。

And while gravitational waves are exciting, "there's a lot more to be learned through electromagnetic waves and gravitational waves than that is to be learned through gravitational waves alone." When the LIGO gravitational wave detector fires up, early next year, he says, he'll be watching, waiting, perhaps, for his next study subject. 

尽管引力波是令人兴奋的，“但通过电磁波和引力波可以学到的东西比仅仅通过引力波学到的要多得多。”他说，当LIGO引力波探测器明年初启动时，他将会观察、等待，或许，等待他的下一个研究课题。