A cluster of galaxies in the C-EAGLE simulation shows a portion of the image with filaments similar to those detected in reality.
The colored map simulates the newly discovered structure: a cluster of galaxies forms at the intersection of this cosmic network.
In the cold space wild seemingly distant galaxies hold together resisting the call of black holes. In the darkness of great distances it is a “mesh”, a net, a gas road car that keeps them united and in connection with each other.
This intergalactic gaseous network is known in cosmological models as the "cosmic network". Formed by long strands of hydrogen left as a trace by the Big Bang, the network contains most of the gas in the universe (more than 60%) and is also a storehouse of substance for the creation of new stars. At the intersection of these "gas paths" galaxies are born: this is the theory.
The filaments of the cosmic web have never been observed directly before, because they are among the "weakest" structures and easily obscured by the reflection of the galaxies that surround them. Now however, in a study published today in Science, the researchers assembled the first photo in history showing this "gas highway" bringing galaxies to life and connecting them together.
The merit is all of the cooperation of some of the most sensitive terrestrial telescopes.
"These observations of the largest and thinnest structures in the universe are the key to understanding how our universe has evolved over time," says Erika Hamden, a University of Arizona observatory astronomer not involved in the research. “They are the tip of the iceberg, it is a network that connects the whole universe”.
A dark road
The new study finally clarifies a reality: this gaseous network has filaments so thin that without a glare from the galaxies it would be indistinguishable from cosmic darkness.
And indeed the discovery was made using galaxies like flashes.
Using an instrument called the “Multi-unit Spectroscopic Explorer” on the European Southern Observatory, the researchers focused on an ancient group of galaxies located in the constellation Aquarius. Using the reflection of the light of the young stars in formation, they were then able to draw a vague map of this network.
The structures observed
The researchers detected two parallel highways of gas linking galaxies millions of light years away, crossed with another motorway linking them crosswise. The gas filaments seem to feed the forming galaxies like blood vessels in a uterus, pumping hydrogen directly to the center of only babies and black holes.
However, the study of this structure is still very complicated. The weakness of the filaments makes them difficult to detect, and for the same reason only the most enlightened ones are detectable.