Astronomers spot galaxy shaped like the Milky Way but is far more massive
天文学家发现形似银河系但质量远超的星系
WASHINGTON, May 23 (Reuters) – Astronomers have observed a galaxy dating to an earlier epoch in the universe’s history that surprisingly is shaped much like our Milky Way – a spiral structure with a straight bar of stars and gas running through its center – but far more massive, offering new insight into galactic formation.
华盛顿，5 月 23 日（路透社）——天文学家观测到一个可追溯至宇宙历史更早期阶段的星系，其形态竟与我们的银河系惊人相似——拥有螺旋结构及贯穿中心的恒星与气体直棒，但质量远超银河系，为星系形成提供了新见解。
The distant galaxy, called J0107a, was observed as it appeared 11.1 billion years ago, when the universe was about a fifth of its current age. The researchers used data from the Chile-based Atacama Large Millimeter/submillimeter Array (ALMA) and NASA’s James Webb Space Telescope to study the galaxy.
这个名为 J0107a 的遥远星系被观测到时的状态是 111 亿年前，那时宇宙的年龄仅为现在的五分之一左右。研究人员利用位于智利的阿塔卡马大型毫米/亚毫米阵列（ALMA）和美国宇航局詹姆斯·韦伯太空望远镜的数据对该星系进行了研究。
They determined that the galaxy’s mass, including its stars and gas, was more than 10 times greater than that of the Milky Way, and it was forming stars at an annual rate approximately 300 times greater. J0107a was more compact than the Milky Way, however.
他们测定该星系的总质量（包括恒星和气体）是银河系的十倍以上，其恒星形成速率约为银河系的 300 倍。不过，J0107a 的结构比银河系更为致密。
“The galaxy is a monster galaxy with a high star formation rate and plenty of gas, much more than present-day galaxies,” said astronomer Shuo Huang of the National Astronomical Observatory of Japan, lead author of the study published this week in the journal Nature.
“这个星系是个拥有极高恒星形成率和丰富气体的巨无霸星系，远超现今的星系，”日本国立天文台的天文学家、本周发表在《自然》期刊上的该研究主要作者黄硕表示。
“This discovery,” said study co-author Toshiki Saito, an astronomer at Shizuoka University in Japan, “raises the important question: How did such a massive galaxy form in such an early universe?”
“这一发现，”该研究的合着者、日本静冈大学的天文学家斋藤俊树说，”提出了一个重要问题：如此巨大的星系是如何在宇宙如此早期形成的？”
While a few galaxies that are undergoing star formation at a similar rate to J0107a exist in today’s universe, almost all of them are ones that are in the process of a galactic merger or collision. There was no sign of such circumstances involving this galaxy.
尽管现今宇宙中存在少数与 J0107a 恒星形成速率相近的星系，但其中几乎所有的星系都正处于星系合并或碰撞的过程中。而该星系并未显示出此类迹象。
J0107a and the Milky Way have some commonalities.
J0107a 与银河系存在某些共同特征。
“They are similarly huge and possess a similar barred structure. However, the Milky Way had plenty of time to form its huge structures, while J0107a didn’t,” Saito said.
赛托表示：”它们同样巨大，且拥有相似的棒状结构。然而，银河系有充足的时间形成其庞大结构，而 J0107a 则没有。”
In the first few billion years after the Big Bang event 13.8 billion years ago that initiated the universe, galaxies were turbulent entities and were much richer in gas than those existing currently – factors that fostered extreme bursts of star formation. While galaxies with highly organized structures like the barred spiral shape of the Milky Way are common now, that was not the case 11.1 billion years ago.
在 138 亿年前引发宇宙的大爆炸事件后的最初几十亿年里，星系是动荡不安的实体，其气体含量远高于现今存在的星系——这些因素促成了极端的恒星形成爆发。虽然像银河系这样具有棒旋结构的组织化星系如今很常见，但在 111 亿年前情况并非如此。
“Compared to other monster galaxies in the distant universe (dating to an earlier cosmic epoch) whose shapes are usually disturbed or irregular, it is unexpected that J0107a looks very similar to present-day spiral galaxies,” Huang said.
“相较于遥远宇宙（对应更早宇宙时期）中通常形态扭曲或不规则的其他巨型星系，J0107a 看起来与现今的螺旋星系极为相似，这出乎意料，”黄说道。
“Theories about the formation of present-day galactic structures may need to be revised,” Huang added.
“关于现今星系结构形成的理论可能需要重新审视，”黄补充道。
The Webb telescope, as it peers across vast distances back to the early universe, has found that galaxies with a spiral shape appeared much earlier than previously known. J0107a is now one of the earliest-known examples of a barred spiral galaxy.
韦伯望远镜在遥望早期宇宙的浩瀚距离时发现，螺旋形状的星系出现时间比此前认知的要早得多。J0107a 现在是已知最早的棒旋星系范例之一。
About two thirds of spiral galaxies observed in the universe today possess a bar structure. The bar is thought to serve as a form of stellar nursery, bringing gas inward from the galaxy’s spiral arms. Some of the gas forms what are called molecular clouds. Gravity causes the contraction of these clouds, with small centers taking shape that heat up and become new stars.
现今宇宙中观测到的螺旋星系约三分之二具有棒状结构。这种棒状结构被认为是一种恒星孕育场所，能将气体从星系的旋臂向内输送。部分气体形成了所谓的分子云。引力导致这些云团收缩，形成小型核心并升温，最终诞生新恒星。
The bar that is part of J0107a measures about 50,000 light years in length, Huang said. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km).
黄表示，J0107a 星系的棒状结构长度约 5 万光年。一光年即光在一年内行进的距离，相当于 5.9 万亿英里（9.5 万亿公里）。
The Webb telescope “has been studying the morphology of early massive galaxies intensely recently. However, their dynamics are still poorly understood,” Saito said.
斋藤指出：”韦伯望远镜近期正密集研究早期大质量星系的形态特征，但其动力学机制仍知之甚少。”