Astronomers have discovered the largest rotating structure in the universe by mapping the motion of galaxies in the massive filaments that connect the cosmic web.
The long tendrils of these galaxies rotate on a scale of hundreds of millions of light years. According to astronomers at the Leibniz Institute for Astrophysics in Potsdam (AIP), we have never seen a rotation on such a large scale.
The results, published in Nature Astronomy, show that angular momentum can be generated at an unprecedented rate.
Such potential flows are illogical or wrinkle-free: there was no primordial rotation in the early universe and angular momentum had to be created when structures formed.
The cosmic filament is the massive bridge of galaxies and dark matter that connects clusters of galaxies together. They direct galaxies to and from the large clusters located at their ends.
According to Peng Wang, study author and AIP astronomer, “By mapping the movement of galaxies in this massive cosmic fashion using the Sloan Digital Sky Survey—a survey of hundreds of thousands of galaxies—we discovered an extraordinary property of these filaments: orbits. ”
Added Noam Libeskind, project initiator at AIP.
“At this scale, the galaxies within themselves are just dust samples. They move in a spiral or helical orbit, and rotate around the center of the axis as they move with it. Such a spin has never been seen before on a planet of this size. scales, and the result is certain. There is a hitherto unknown physical mechanism that is responsible for the torsion of these objects.”
How to generate rotating angular momentum in a cosmological context is one of the main unresolved problems in cosmology. In the Standard Model of structure formation, the small excess density found in the early universe grew through gravitational instability as matter flowed from below into regions of excess density.
Such potential flows are illogical or curvilinear: there was no primitive rotation in the early universe. Thus, each rotation must be created as a structure. Cosmic webs in general and filaments in particular are closely related to the formation and evolution of galaxies. It also has a strong influence on the rotation of galaxies, often regulating the direction of rotation of galaxies and halos of dark matter. However, it is not known whether the current understanding of structure formation predicts that the filaments themselves, as non-particle semi-linear bodies, should spin.
Motivated by the theorist’s advice Dr. Mark Nerink that the filaments may be rotating, we examined the distribution of the observed galaxies for filament rotation,” said Noam Libeskind. “It’s great to see this confirmation that intergalactic filaments circulate in the real universe, as well as in computer simulations.”
Using sophisticated mapping methods, the observed galaxy distribution is divided into filaments. Each filament is rounded by a cylinder. The galaxies within it are divided into two regions on either side of the filamentous backbone (in projection) and the mean redshift difference between the two regions is carefully measured.
The mean redshift difference is a proxy for the velocity difference (Doppler shift) between galaxies on the receding side and the approaching side of the filament tube. Thus it can measure the rotation of the filament. Studies show that, depending on the angle of view and the mass of the endpoint, the filaments in the universe show clear signals consistent with rotation.
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