The cosmic web theory holds that galaxies are held together by gravity. For the first time, this structure has been observed by scientists.
Through the European’s Southern Observatory’s Very Large Telescope, scientists were able to detect a cluster of galaxies over 12 billion light years away. The galaxies are in the Aquarius constellation and are linked together by a network of gas filaments.
Cosmic web is one of the front running theories to explain how galaxies were formed after the big bang, but until this latest observation the theory lacked convincing evidence.
Professor Michele Fumagalli, an astrophysicist at Durham University and co-author of the work, said: “it is very exciting to clearly see for the first time multiple and extended filaments in the early universe. We finally have a way to map these structures directly and to understand in detail their role in regulating the formation of supermassive black holes and galaxies.”
It is thought that 60% of hydrogen created during the big bang has been spread across space in the cosmic web. Theoretical predictions indicate that galaxies rely on these hydrogen filaments to form and evolve. The team were able to spot a new forming galaxy cluster and were able to detect the individual filaments of hydrogen gas.
Prior evidence of the theory had shown short blob of gas beyond galaxies, but the team’s observation was the first to show extended filaments. This bolsters the cosmic web argument because it indicates that the hydrogen gas that was created in the big bang collapses firstly into sheets and then expands out into space in filaments. In areas where the filaments come to intersect, they provide growth to the formation of new galaxies through a steady supply of gas
The newest discovery shows that the crossovers between large filaments were at one time home to active galactic centres. They held supermassive black holes and “starbursting” galaxies that have stars actively forming.
Hideki Umehata, the first author on the research, said “This suggests very strongly that gas falling along the filaments under the force of gravity triggers the formation of starbursting galaxies and supermassive black holes, giving the universe the structure that we see today.”
The whole report can be found in the journal Science Vol 366, Issue 6461
Last modified: 18th October 2019