This intergalactic filament is 50 million-light-years lengthy, the longest we have ever seen
An optical image of the Abell 3391/95 system, on which scientists discovered the longest filament ever observed. (Photo credit: Reiprich et al., Astronomy & Astrophysics)
Exceptionally long filaments of hot gas known as intergalactic filaments connect and surround galaxies and galaxy clusters throughout the cosmos – and scientists have just discovered the longest that has ever existed.
intergalactic filaments form a cosmic web that extends across the observable universe. Within this structure, galaxies are arranged in a web-like pattern that is connected by and surrounded by these filaments.
According to previous research, after the Big Bang kicked off our universe 13.8 billion years ago, much of the hydrogen gas that makes up the known matter in the universe collapsed into layers that further disintegrated into long, winding filaments.
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Now scientists, led by researchers from the University of Bonn, have observed the longest filament ever found. The gas thread stretches for an astonishing 50 million light years and its structure agrees with predictions made by the researchers according to a computer simulation published by the University of Bonn.
“According to calculations, more than half of all baryonic matter in our universe is contained in these filaments – this is the form of matter that stars and planets are made of, just like us,” said Thomas Reiprich, a professor at Das Argelander Institute for astronomy at the University of Bonn said in the same statement.
Because the filaments stretch so much, the particles that make them up are very dispersed, making them extremely difficult to see. However, Reiprich and his colleagues were able to make the gas fully visible for the first time by using the eROSITA space telescope, an X-ray telescope that, according to the Max Planck Institute for Extraterrestrial Physics, was built in Germany.
“eROSITA has very sensitive detectors for the type of X-ray radiation emitted by the gas in filaments,” said Reiprich about the observations. “It also has a large field of view – like a wide-angle lens, it covers a relatively large part of the sky in a single measurement and with a very high resolution.” These aspects of the space telescope allow researchers to take detailed images of huge objects like the filaments, and do it relatively quickly.
On the right the eROSITA image, on the left a computer simulation for comparison. (Photo credit: Reiprich et al., Space Science Reviews, 177, 195; right)
The team studied Abell 3391/95 – a system of three galaxy clusters located 700 million light years from Earth. The images captured with eROSITA show the clusters and individual galaxies that have speckled the system, but perhaps even more amazingly they show the tendrils connecting the galaxies and clusters, with the entire filament spanning 50 million light years.
Although this is the longest filament ever observed, the researchers believe it could be even longer than the section shown in the pictures, according to the statement.
“We compared our observations with the results of a simulation that reconstructs the evolution of the universe,” said Reiprich. “The eROSITA images are strikingly similar to computer-generated graphics. This suggests that the generally accepted standard model for the evolution of the universe is correct.”
This work was described in a study that was accepted for publication in the journal Astronomy & Astrophysics.
Email Chelsea Gohd at cgohd@space.com or follow her on Twitter @chelsea_gohd. Follow us on Twitter @Spacedotcom and on Facebook.