Astronomers detect an extremely powerful stream of radio waves from a distant galaxy
Astronomers have discovered an extremely powerful stream of radio waves coming from a very distant galaxy, which took eight billion years to reach Earth, a discovery that will help unravel the mystery of this cosmic phenomenon, according to a study published Thursday.
A fast radio burst, a flash of electromagnetic waves lasting less than a millisecond, finally reached Earth on June 10, 2022, and an Australian telescope was able to pick up its signal.
It turned out that this flow came from a galaxy much more distant than the one that was the source of previously recorded fast radio bursts, as it crossed eight billion light-years, a time when the universe was less than half its current age, according to what astronomers revealed in the journal Science.
Since such signals were first discovered in 2007, scientists have wondered about the exact origin of this cosmic phenomenon, which is difficult to determine because it is hidden. Because these signals were sometimes repeated, some initially assumed they were space-borne radio communications originating from extraterrestrials. In a more serious hypothesis, scientists suggest that the origin of these flows is a very dense dead star called a magnetar, which has an extremely strong magnetic field.
Study co-author Ryan Shannon, from Australia’s Swinburne University in Melbourne, said in a statement to Agence France-Presse that the ability of the ASKAP telescope in Western Australia to detect these fast radio bursts is “amazing.” The astrophysicist added: “We were lucky to be able to observe this small dot in the sky for a fraction of a thousandth of a second, after the flow had passed eight billion years to be observed.”
This new radio flux far exceeded the previous record for a similar flux that took five billion light-years to reach Earth. The new flow was extremely powerful, releasing in less than a millisecond as much energy as the sun emits in 30 years.
The scientist explained, “The sky witnesses perhaps hundreds of thousands of fast radio bursts every day, but only a thousand of them have been observed so far, and researchers have been unable to determine the galaxy from which they came only in about fifty cases, knowing that it is an essential element for understanding this phenomenon.”
To determine the source of this distant radio burst, called FRB 20220610A, researchers turned to the VLT (Verry Large Telescope) in Chile. This telescope showed that the signal was coming from a very dense galaxy that may have merged into one or two other galaxies, giving rise to the strange magnetar.
But for Shannon, this explanation is nothing more than the “best intuition” of scientists, explaining that the committee responsible for giving the final opinion has not yet decided on its reasons, given that the radio bursts were detected in unexpected places, including within the Milky Way Galaxy. In the meantime, these radio bursts may contribute to clarifying another mystery, which is the amount of solid matter in the universe, which is believed to represent about 5 percent of the universe, while the rest consists of dark matter and dark energy. However, the problem is that more than half of this five percent of the solid material is missing.
Scientists believe it lies in the cosmic web, thin threads of gas that connect galaxies to each other, but which are so widespread that they are not visible to telescopes. This gas actually causes changes in the wavelength of fast radio bursts, and thus makes it possible to measure the intensity of the latter. The fast radio bursts recorded by the Australian telescope bear the signature of “excess matter,” according to the researcher.
There is still a need to record a large number of radio waves to improve calculations of the missing matter, and it is expected that new telescopes dedicated to radio astronomy will be created soon.
(AFP)
