APOD
我们从地球上看到的这个强烈扭曲的星系对,编号为Arp81。它们已经碰撞了一亿年了。碰撞时,两个星系的重力相互作用引发了一场浩劫。从这张彩色合成图像中,可以看到扭曲的气体和尘埃,大量恒星形成的混乱、绵延20万光年的潮汐尾扫荡着星系残骸。图中NGC6622(左)和NGC6621两个星系大小大致相等,在遥远的未来注定要经历同样的过程,合并成一个巨大的星系。这个星系对位于天龙座,离我们2.8亿光年。这幅锐利的合成图像来自于哈勃归档数据(Hubble Legacy Archive data),在更遥远的背景上,还可以分辨出一些星系。
Explanation: From planet Earth, we see this strongly distorted pair of galaxies, cataloged as Arp 81, as they were only about 100 million years after their close encounter. The havoc wreaked by their mutual gravitational interaction during the encounter is detailed in this color composite image showing twisted streams of gas and dust, a chaos of massive star formation, and a tidal tail stretching for 200 thousand light-years or so as it sweeps behind the cosmic wreckage. Also known as NGC 6622 (left) and NGC 6621, the galaxies are roughly equal in size but are destined to merge into one large galaxy in the distant future, making repeated approaches until they finally coalesce. Located in the constellation Draco, the galaxies are 280 million light-years away. Even more distant background galaxies can be spotted in this sharp, reprocessed, image from Hubble Legacy Archive data.
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