If we could zoom out of the universe, we would see galaxies organized in clusters, and those clusters form superclusters that are distributed along dense filaments between under-dense voids. On the largest scales the universe looks the same everywhere, but looking closer to these filaments we can see peculiar and unique structures.
One of them is the newly discovered BOSS Great Wall. The system consists of 830 galaxies and has a mass of 280 million billion suns. It is about 5 billion light-years away from the Milky Way, and it is 1.3 billion light-years in diameter.
The BOSS Great Wall is not the first cosmic wall discovered. The largest structure in the nearby universe is the Sloan Great Wall, which has about half the mass of the BOSS Great Wall. Claims on these structures are quite contentious, though, as although they appear as a single structure in the sky, they are not bound together by gravity like clusters and superclusters.
"We found two walls of galaxies [...] that are larger in volume and diameter than any previously known superclusters. Together they form the system of the BOSS Great Wall, which is more extended than any other known structure," said the researchers in the paper, which will appear in Astronomy & Astrophysics.
According to our current model of the universe, structures shouldn't be larger than 1.2 billion light-years, but this is not the first time that scientists have claimed the existence of structures larger than what the model predicts.
The BOSS Great Wall was discovered by Heidi Lietzen of the Canary Islands Institute of Astrophysics and her team. They were observing a large chunk of the universe between 4.5 to 6.4 billion light-years from Earth.
“It was so much bigger than anything else in this volume,” Lietzen said to New Scientist.
While this mass grouping is definitely interesting, other scientists are questioning the discovery.
“I don’t entirely understand why they are connecting all of these features together to call them a single structure,” says Allison Coil of the University of California, San Diego to New Scientist. “There are clearly kinks and bends in this structure that don’t exist, for example, in the Sloan Great Wall.”
[H/T: New Scientist]