Astronomers find a cosmic Titan in the early universe

An international team of astronomers has discovered a titanic structure in the early Universe, just two billion years after the Big Bang. This galaxy proto-supercluster, nicknamed Hyperion, is the largest and most massive structure yet found at such a remote time and distance.

The University of California, Italy, and the scientist Brian Lemaux in the Department of Physics, College of Letters and Science at the University of California, Davis, and included Lori Lubin , professor of physics at UC Davis. They used the VIMOSinstrument on ESO's Very Large Telescope in Paranal, Chile to identify a gigantic proto-supercluster of galaxies forming in the early Universe, just 2.3 billion years after the Big Bang.

Hyperion is the largest and most massive structure in the world, with more than one million trillion times that of the Sun. This enormous mass is one of the largest structures observed in the Universe today, but finding such a massive object in the early Universe surprised astronomers.

"This is the first time that such a large structure has been identified at such a high redshift, just over 2 billion years after the Big Bang," Cucciati said. "Normally these kinds of structures are known to lower redshifts, which means that the Universe has had a lot more to do with it.

Supercluster mapped in three dimensions

Located in the constellation of Sextans, Hyperion was identified by a novel technique developed at UC Davis to analyze the VIMOS Ultra-Deep Survey led by Olivier Le Fèvre from Marseille Astrophysics Laboratory, National Center for Scientific Research and National Center for Space Studies. The VIMOS instrument can measure the distance to galaxies at the same time, making it possible to map the position of galaxies within the supercluster in three dimensions.

The team found that Hyperion has a very complex structure, containing at least seven high-density regions connected by filaments of galaxies, and its size is comparable to superclusters closer to Earth, though it has a very different structure.

"Superclusters closer to Earth tend to a much more concentrated distribution of mass with clear structural features," Lemaux said. "But in Hyperion, the mass is distributed much more uniformly in a series of connected blobs, populated by loose associations of galaxies."

The researchers are comparing the findings with the findings of the Overseas Survey of Large Scale Environments (ORELSE), led by Lubin. The ORELSE survey uses telescopes at the W.M. Keck Observatory in Hawaii to study superclusters closer to Earth. Lubin and Lemaux are also using the Keck observatory to map out Hyperion and similar structures more completely.

The contrast between Hyperion and the remote superclusters is most likely due to the fact that superclusters have had more than one billion years of aging in the past.

Given its size so in the history of the Universe, Hyperion is expected to evolve into something similar to the huge structures in the local universe as the superclusters making the Sloan Great Wall or the Virgo Supercluster that contains our own galaxy, the Milky Way.

"Understanding Hyperion and how it compares to similar recent structures can give insights into how the world will develop," he said. "Unearthing this cosmic titan helps uncover the history of these large-scale structures."

This research will be published in an upcoming issue of the journal Astronomy & Astrophysics.

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More information:
O. Cucciati et al. The progeny of a cosmic titan: a massive multi-component proto-supercluster in formation at z = 2.45 in VUDS, Astronomy & Astrophysics (2018). DOI: 10.1051 / 0004-6361 / 201833655