这是宇宙？

Astronomers have discovered the largest known structure in the universe, a clump of active galactic cores that stretches 4 billion light-years from end to end.

The structure is a large quasar group (LQG), a collection of extremely luminous galactic nuclei powered by supermassive central black holes. This particular group is so large that it challenges modern cosmological theory, researchers said.

"While it is difficult to fathom the scale of this LQG, we can say quite definitely it is the largest structure ever seen in the entire universe," lead author Roger Clowes, of the University of Central Lancashire in England, said in a statement. "This is hugely exciting, not least because it runs counter to our current understanding of the scale of the universe."

Quasars are the brightest objects in the universe. For decades, astronomers have known that they tend to assemble in huge groups, some of which are more than 600 million light-years wide.

But the record-breaking quasar group, which Clowes and his team spotted in data gathered by the Sloan Digital Sky Survey, is on another scale altogether. The newfound LQC is composed of 73 quasars and spans about 1.6 billion light-years in most directions, though it is 4 billion light-years across at its widest point.

To put that mind-boggling size into perspective, the disk of the Milky Way galaxy — home of Earth's solar system — is about 100,000 light-years wide. And the Milky Way is separated from its nearest galactic neighbor, Andromeda, by about 2.5 million light-years.

The newly discovered LQC is so enormous, in fact, that theory predicts it shouldn't exist, researchers said. The quasar group appears to violate a widely accepted assumption known as the cosmological principle, which holds that the universe is essentially homogeneous when viewed at a sufficiently large scale.  

Calculations suggest that structures larger than about 1.2 billion light-years should not exist, researchers said.

"Our team has been looking at similar cases which add further weight to this challenge, and we will be continuing to investigate these fascinating phenomena," Clowes said.

The new study was published today (Jan. 11) in the Monthly Notices of the Royal Astronomical Society.

Follow SPACE.com senior writer Mike Wall on Twitter @michaeldwall or SPACE.com@Spacedotcom. We're also on Facebook and Google+. 

借助 Google，试翻一下：

什么新闻也没这个大，别太认真！:)

天文学家已经发现了宇宙中已知最大的结构，一丛活动的星系核，从端到端绵延40亿光年年。

结构是一个大的类星体组（LQG），电中央的超大质量黑洞非常明亮的星系核的集合。这个特殊的群体是如此之大，它挑战了现代宇宙学理论，研究人员如是说。

“虽然是很难捉摸这LQG的规模，我们可以说相当肯定，它是在整个宇宙中见过的最大的结构”，第一作者Roger Clowes，在英国中央兰开夏大学在一份声明中说。“这是非常令人兴奋的，因为它违背了我们目前的了解宇宙的规模。”

类星体是宇宙中最明亮的天体。几十年来，天文学家已经知道，他们往往聚集在庞大的群体，其中有一些是超过6亿光年宽。

但破纪录的类星体，Clowes和他的团队发现了斯隆数字巡天计划所收集的数据，是完全在另一个规模。新发现的LQC是由73个类星体，各方向跨度约16亿光年，但它的最大跨度约是40亿光年。

令人难以置信的大小，角度，银河系的磁盘地球上的太阳能系统-家庭-大约10万光年宽。和分离其最近的银河系邻居，仙女座星系，约2.5百万光年的银河系。

新发现的LQC是如此巨大，实际上，这理论预测它不应该存在的，研究人员说。类星体似乎违反了一个被广泛接受的假设被称为宇宙学原理，认为宇宙在一个足够大的规模里，本质上是均匀的。

计算表明，大于约12亿光年的结构不应该存在的，研究人员说。

Clowes表示：“我们的团队一直在类似的情况下，进一步增加重量这一挑战，我们将继续调查这些迷人的现象，”。

今日（1月11日）的英国皇家天文学会月刊“上的这项新的研究发表。