A piece of the universe made up of filaments and spaces. Along the filaments, galaxies move towards large galaxy clusters – by rotating around the axis of their filament. Astronomers have now proven this for the first time (artist’s impression Nasa)
This discovery could lead to new insights into the origin of the rotational movements. “Where the angular momentum comes from in the cosmic framework is one of the unsolved riddles of cosmology,” explains Pen Wang’s team from the Leibniz Institute for Astrophysics in Potsdam. In today’s standard model, all cosmic structures arise from the slow compression of originally evenly distributed matter. In the initial state after the Big Bang, however, there were no rotational movements – so where do the observed rotations come from?
With their observations, Wang and his colleagues have come a little closer to an answer to this question. Galaxies are not evenly distributed in the cosmos. They form large piles, which in turn are connected by elongated, thin structures. In these filaments, galaxies slowly flow towards the large galaxy clusters, which sit like knots in a network of filaments.
The team studied the movement of galaxies in thousands of filaments. The result: the galaxies do not move randomly, but follow a rotational movement around the axis of their filament.
These are the greatest rotational movements that have ever been discovered in the universe. “Although these are thin cylinders that are hundreds of millions of light years long, but only a few million light years in diameter, these fantastic streams of matter rotate,” says project initiator Noam Libeskind from the Leibniz Institute.
As the researchers’ observations also show, the more massive the galaxy clusters are at its end, the stronger the rotation of a filament. According to astronomers, this indicates that the cosmic filaments not only play an important role in the formation and development of galaxies and galaxy clusters, but also influence the rotational movements in the universe.
Only recently had computer simulations of the formation of large structures in the cosmos provided indications of a possible rotation of filaments. “It’s fantastic to see confirmation that intergalactic filaments rotate both in the real universe and in computer simulations,” says Libeskind.
* Article number DOI: 10.1038 / s41550-021-01380-6