In our cosmos, rotation is common . Everything we see turns in one way or another. Our planet (and everything on it) rotates on its axis, as do all the planets and moons in the solar system, asteroids or galaxies. Objects rotate on their axis and around other more massive objects . However, giant clusters of galaxies do so very slowly, if they rotate, hence scientists have believed that this is where the phenomenon of rotation could go. But what happens on the largest of cosmic scales?
Now, a new study led by astronomers from the Leibniz Institute for Astrophysics in Potsdam and published in the journal Nature Astronom and proposes that cosmic filaments, the largest known structures in the universe that can be between 160 and 260 million light years long and they are the threads of the cosmic web, they also rotate on an axis. The strands of the cosmic network or giant tubes made of galaxies, would therefore be rotating around the filamentary axis itself.
Can we explain it?
Using data from the Sloan Digital Sky Survey, the scientists examined more than 17,000 filaments and analyzed the speed at which the galaxies that make up these giant tubes were moving within each cosmic strand. The astronomers found that the way these galaxies moved suggested that they rotated around the central axis of each filament (up to a maximum speed of 360,000 kilometers per hour). The authors noted that they do not suggest that all the filaments in the universe spin, but that spinning filaments do appear to exist.
“By mapping the motion of galaxies on these huge cosmic superhighways using the Sloan Digital Sky study, a study of hundreds of thousands of galaxies, we found a remarkable property of these filaments: they rotate,” says Peng Wang, leader of the work.
Observing the motion of the galaxies on both sides of the supposed axis of rotation, they saw that, indeed, the galaxies on one side seemed to move towards us and on the other, away, which is what we would expect from a rotating object. Also, the filaments that had the most massive collections of galaxies at each end seemed to spin faster than the others.
“At these scales, the galaxies within them are themselves just samples of dust . They move in helices or corkscrew-shaped orbits, circling around the center of the filament as they travel along it. They have never been before. seen such a twist on such enormous scales, and the implication is that there must be a still unknown physical mechanism responsible for squeezing these objects “, clarifies Noam Libeskind, co-author of the work.
Why do they rotate?
Scientists do not know how such properties of physics arose in the early universe, but understanding how it influences the largest structures in the universe could be key to unraveling this mystery.
The intention is to understand the origin of the spinning of the filaments through computer simulations to see how matter behaves on the largest cosmological scales.
Referencia: Wang, P., Libeskind, N.I., Tempel, E. et al. Possible observational evidence for cosmic filament spin. Nature Astronomy (2021). https://doi.org/10.1038/s41550-021-01380-6
