The oldest fastest radio flash ever to «weigh» the Universe

Australian scientists have described a radio burst, whose signal flew to Earth for about eight billion years.

Current methods of calculating the mass of the universe give controversial results. Scientists suggest that part of the uncounted matter may be in the space between galaxies. But it's so rarefied that modern telescopes can't detect it. But fast radio bursts can: they "bump" into the free electrons left by ionized gas. By its presence can already be judged on the concentration of ordinary matter in general.

Australian astrophysicist Jean-Pierre Macquart (Jean-Pierre Macquart) with colleagues showed a strong correlation between the measure of dispersion of a particular fast radio burst and the redshift of the galaxy that generated it: the farther away the galaxy, the more matter in the space between us and the source.

In the calculations, the researchers used fast radio bursts from confirmed sources with redshift less than 0.5. This relationship was assumed to hold for distant sources. But a year ago, scientists described a signal from a galaxy with an offset z = 0.241, the dispersion of which showed an offset z > 1. It was probably affected by conditions inside the galaxy.

The new distant radio burst, which came to us through half of the known Universe, indeed confirmed Makkar's relation.

An international team of scientists led by Australian astronomers found the fast radio burst FRB 20220610A, "caught" in June 2022, in the observational data of the ASKAP radio interferometer.

Using the VLT telescope in Chile's Paranal Observatory and data from ASKAP astronomers were able to determine the source of the radio burst - in a small group of merging galaxies. The results are published in Science.

"Even though we still don't know exactly where these powerful bursts of energy come from, the study confirms that this is a frequent event in the cosmos. So, we can use them to search for matter between galaxies to better understand the structure of the universe," commented co-author Ryan Shannon, a professor at Swinburne University of Technology (Australia).

The discovery confirmed the suggestion that fast radio bursts can measure the amount of matter in intergalactic space - the "lost" matter. This is a new way of "weighing" the Universe.

SKA, the world's largest radio interferometer, is being built in western Australia and South Africa. According to the plan, it should work in 2027. With its help, scientists will be able to catch even older fast radio bursts.