Category: English | 15 Июнь 2021
Planets, stars, galaxies, and other galaxy clusters ... All these objects rotate in the universe. A recent study suggests that angular momentum also acts on a much larger scale.
It is difficult to imagine the structure of the universe, but if we took many, many steps back, we would notice that the distribution of matter in the cosmos is uneven. Its structure resembles a giant cosmic web of incredibly long filaments, inside which galaxies move.
In one study, a team of scientists points to evidence that these filamentous structures, stretching hundreds of millions of light-years, rotate on their own.
As part of this work, astronomers from the Leibniz Institute for Astrophysics in Potsdam (AIP), Germany, mapped the motion of the galaxies contained in these huge cosmic highways. To do this, they used data from the Sloan Digital Sky program, which monitors celestial objects from the Apache Observatory in New Mexico (USA), to analyze their light.
When light waves pass through space-time, the expansion of the universe expands them towards the red end of the electromagnetic spectrum. Conversely, the wavelength of light from an approaching object will appear slightly shortened towards the blue part of the spectrum. This is called the Doppler effect.
Figure 1 shows a clear example of the Doppler effect on sound waves. When the car approaches, the distance between the sound waves of the siren decreases, and when it is removed, the distance between the waves increases.
Figure 1. Example of the Doppler effect
By carefully studying the light from the galaxies in some of these cosmic filaments and comparing them with each other, the astronomers found that the light from the galaxies located on one side of the filament was shifted to the red side relative to the light from the galaxies on the other side.
According to the authors, who published their work in the journal Nature Astronomy, all these galaxies would thus move in orbits in the form of a "corkscrew", rotating around the center of the thread as it moves along it.
Such rotation has never been observed on such a huge scale before, and understanding what this mechanism is may help astronomers understand how angular momentum originated in space in the first place. So far, this is a mystery.
Fig. 2. The artist's idea of the cosmic filaments in which the galaxies move. The light from the upper halves of the filaments has a red shift (moving away from us), and from the lower halves - a blue shift (moving towards us).