Astronomers observe proof of the cosmic web's existence

A team with the Very Large Telescope of the European Southern Observatory (ESO) and the Subaru Telescope of the National Astronomical Observatory of Japan (NAOJ) are studying a distant galaxy structure, a new clue to the formation of the cosmic web.

Masayuki Tanaka from ESO, who led the new study explains that matter clumps unevenly throughout the universe, locally as stars, galaxies and galaxy clusters. He accepts the cosmological theory that matter clumps together on the universal scale as well, as gigantic, wispy filaments, embedded with galaxies, stretching across vast voids. This universal framework is sometimes called a cosmic skeleton or the cosmic web. Cosmic web strands are theorized to be millions of light years long. Tanaka's team's discovery, within images that were obtained earlier, of an immense structure around a distant galaxy cluster is the first solid proof that the this cosmic web exists. The team is now studying this structure in greater detail, measuring the distances from Earth of its150 galaxies to get a three-dimensional perspective, and performing spectroscopic analysis. The astronomers have identified several clumps of galaxies in the distant structure around the main galaxy cluster. Each smaller group of galaxies is from ten to a thousand times as massive as our Milky Way galaxy. They estimate the total mass of the galaxy cluster to be at least ten thousand times the mass of our Milky Way, and that its gravity will eventually pull in many of the surrounding galaxy clumps. The filament and galaxy cluster being observed in this study is located about 6.7 billion light-years away, and extends at least 60 million light-years. Tanaka and his team speculate that it may stretch far beyond the field being probed by their study. Future observations are planned to obtain more accurate measurements and demographics. Tanaka et al. have published their observations in the Astronomy & Astrophysics Journal: The spectroscopically confirmed huge cosmic structure at z = 0.55.