After combing through NASA’s James Webb Space Telescope’s archive of sweeping extragalactic cosmic fields, a small team of astronomers at the University of Missouri says they have identified a sample of galaxies that have a previously unseen combination of features. Principal investigator Haojing Yan compares the discovery to an infamous oddball in another branch of science: biology’s taxonomy-defying platypus .
密苏里大学的一个天文学家小组在梳理了美国宇航局詹姆斯·韦伯太空望远镜的河外宇宙场档案后表示，他们已经识别出一个星系样本，这些样本具有以前从未见过的特征组合。首席研究员颜浩晶将这一发现与另一个科学分支中臭名昭著的怪人进行了比较：生物学中违反分类学的鸭嘴兽。
“It seems that we’ve identified a population of galaxies that we can’t categorize, they are so odd. On the one hand they are extremely tiny and compact, like a point source, yet we do not see the characteristics of a quasar, an active supermassive black hole, which is what most distant point sources are,” said Yan.
“我们似乎已经识别出一群无法分类的星系，它们太奇怪了。一方面，它们极其微小和紧凑，就像点源一样，但我们没有看到类星体的特征，类星体是一种活跃的超大质量黑洞，而这正是最遥远的点源的特征，”严说。
The research was presented in a press conference at the 247th meeting of the American Astronomical Society in Phoenix.
这项研究是在凤凰城举行的美国天文学会第 247 届会议的新闻发布会上公布的。
“I looked at these characteristics and thought, this is like looking at a platypus. You think that these things should not exist together, but there it is right in front of you, and it’s undeniable,” Yan said.
“我看着这些特征，想，这就像看鸭嘴兽。你认为这些东西不应该共存，但它就在你面前，这是不可否认的，”严说。
The team whittled down a sample of 2,000 sources across several Webb surveys to identify nine point-like sources that existed 12 to 12.6 billion years ago (compared to the universe’s age of 13.8 billion years). Spectral data gives astronomers more information than they can get from an image alone, and for these nine sources it doesn’t fit existing definitions. They are too far away to be stars in our own galaxy, and too faint to be quasars, which are so brilliant that they outshine their host galaxies. Though the spectra resemble the less distant “green pea” galaxies discovered in 2009, the galaxies in this sample are much more compact.
该团队在几次韦伯调查中缩减了 2000 个源的样本，以确定 12 至 126 亿年前存在的 9 个点状源（相对于宇宙的年龄为 138 亿年）。光谱数据为天文学家提供的信息比仅从图像中获得的信息要多，而对于这九个来源来说，它不符合现有的定义。它们离我们太远，无法成为我们银河系中的恒星，也太暗淡，无法成为类星体，而类星体是如此明亮，以至于比它们的宿主星系还要耀眼。尽管光谱类似于 2009 年发现的距离较近的“绿豌豆”星系，但该样本中的星系要紧凑得多。
“Like spectra, the detailed genetic code of a platypus provides additional information that shows just how unusual the animal is, sharing genetic features with birds, reptiles, and mammals,” said Yan. “Together, Webb’s imaging and spectra are telling us that these galaxies have an unexpected combination of features.”
“就像光谱一样，鸭嘴兽的详细遗传密码提供了额外的信息，显示出这种动物是多么不寻常，与鸟类、爬行动物和哺乳动物有共同的遗传特征，”严说。 “韦伯的成像和光谱共同告诉我们，这些星系具有意想不到的特征组合。”
Yan explained that for typical quasars, the peaks in their characteristic spectral emission lines look like hills, with a broad base, indicating the high velocity of gas swirling around their supermassive black hole. Instead, the peaks for the “platypus population” are narrow and sharp, indicating slower gas movement.
严解释说，对于典型的类星体，其特征光谱发射线的峰值看起来像山丘，具有宽阔的底部，表明气体在其超大质量黑洞周围旋转的速度很高。相反，“鸭嘴兽种群”的峰值狭窄而尖锐，表明气体运动较慢。
While there are narrow-line galaxies that host active supermassive black holes, they do not have the point-like feature of the sample Yan’s team has identified.
虽然有一些窄线星系拥有活跃的超大质量黑洞，但它们并不具有严团队所识别的样本的点状特征。
Has Yan’s team discovered a missing link in the cosmos? Once the team determined that the objects didn’t fit the definition of a quasar, graduate student researcher Bangzheng Sun analyzed the data to see if there were signatures of star-forming galaxies.
严的团队是否发现了宇宙中缺失的一环？一旦团队确定这些物体不符合类星体的定义，研究生研究员孙邦正就分析了数据，看看是否存在恒星形成星系的特征。
“From the low-resolution spectra we have, we can’t rule out the possibility that these nine objects are star-forming galaxies. That data fits,” said Sun. “The strange thing in that case is that the galaxies are so tiny and compact, even though Webb has the resolving power to show us a lot of detail at this distance.”
“从我们掌握的低分辨率光谱来看，我们不能排除这九个天体是恒星形成星系的可能性。这些数据是合适的，”孙说。 “在这种情况下，奇怪的是星系是如此微小和紧凑，尽管韦伯有能力在这个距离向我们展示很多细节。”
One proposal the team suggests is that Webb, as promised, is revealing earlier stages of galaxy formation and evolution than we have ever been able to see before. It is generally accepted across the astronomy community that large, massive galaxies like our own Milky Way grew by many smaller galaxies merging together. But, Yan asks, what comes before small galaxies?
该团队提出的一项建议是，韦伯正如所承诺的那样，揭示了星系形成和演化的早期阶段，比我们以前能够看到的更早。天文学界普遍认为，像我们银河系这样的大型星系是由许多较小的星系合并而成的。但是，严问道，小星系之前是什么？
“I think this new research is presenting us with the question, how does the process of galaxy formation first begin? Can such small, building-block galaxies be formed in a quiet way, before chaotic mergers begin, as their point-like appearance suggests?” Yan said.
“我认为这项新研究向我们提出了一个问题，星系形成的过程首先是如何开始的？在混乱的合并开始之前，如此小的积木星系能否以安静的方式形成，正如它们的点状外观所暗示的那样？”严说。
To begin answering that question, as well as to determine more about the nature of their odd platypuses, the team says they need a much larger sample than nine to analyze, and with higher-resolution spectra.
研究小组表示，为了开始回答这个问题，并进一步确定这些奇怪鸭嘴兽的性质，他们需要比九个更大的样本进行分析，并且需要更高分辨率的光谱。
“We cast a wide net, and we found a few examples of something incredible. These nine objects weren’t the focus; they were just in the background of broad Webb surveys,” said Yan. “Now it’s time to think about the implications of that, and how we can use Webb’s capabilities to learn more.”
“我们撒了一张大网，发现了一些令人难以置信的例子。这九个物体不是焦点；它们只是广泛的韦伯调查的背景，”严说。 “现在是时候考虑一下它的含义，以及我们如何利用韦伯的能力来了解更多信息。”
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).
詹姆斯·韦伯太空望远镜是世界上首屈一指的太空科学天文台。韦伯正在解开太阳系中的谜团，展望其他恒星周围的遥远世界，并探索宇宙的神秘结构和起源以及我们在其中的位置。韦伯是由 NASA 及其合作伙伴 ESA（欧洲航天局）和 CSA（加拿大航天局）领导的一项国际计划。
The following sections contain links to download this article’s images and videos in all available resolutions followed by related information links, media contacts, and if available, research paper and Spanish translation links.
以下部分包含以所有可用分辨率下载本文图像和视频的链接，然后是相关信息链接、媒体联系人以及研究论文和西班牙语翻译链接（如果有）。
More Webb: News | Images | Science | Home Page
更多韦伯：新闻|图片 |科学|主页