Cosmological models have long predicted the existence of filaments – the gas in which galaxies are created – but no images of the phenomenon have been captured, except in the vicinity of quasars, which are high-brightness astronomical objects found in the center of galaxies.
The cosmic network is the constituent element of the cosmos – consisting mainly of dark matter and gas-laced – on which galaxies are built.
Using the MUSE tool, scientists studied a region of the sky called the Hubble Ultra-Deep Field for about 140 hours over eight months. The area is where the deepest images of the cosmos were obtained.
“Galaxies in the sky and in the universe are not evenly distributed,” the study’s lead author, Roland Bacon, an astrophysicist and researcher at the Lyon Astrophysics Research Center in Lyon, told CNN.
“Galaxies in the early days of the universe were formed by gas. Gas, especially hydrogen, is the fuel that forms stars and ultimately forms the galaxy,” he explained. “Galaxies will form in these very long filaments of gas.”
There was some indirect evidence that the gas was present in the region, Bacon said. When the team studied the quasars, they sometimes found that the light was hidden, which they thought was due to the presence of gas.
The team’s analysis of the images captured with the telescope revealed light from the hydrogen filaments.
“The best explanation is that the light we see in the images is not due to the ultraviolet background – it comes from billions of tiny galaxies that form stars, called dwarf galaxies,” Bacon said.
Our large galaxy, the Milky Way, is orbited by more than 50 smaller galaxies, including dwarf galaxies.
While the Milky Way now hosts between 200 and 400 billion stars, dwarf galaxies contain between 100 and several billion.
Dwarf galaxies merged into the early universe to form the larger galaxies that populate it today, including the Milky Way.
“We cannot see these galaxies because they are intrinsically weak and too far away: we observe them 2 billion years after the Big Bang – 11 billion light-years away. But there are so many that we can see the integrated light produced by them, “he said.