2023-10-19 18:00:02
The recently detected fast radio burst 20220610A took eight billion years to reach us (Illustrative image)
SPACE – Mysterious phenomena that last only a few thousandths of a second, but so powerful that they travel beyond galaxies. Their name ? Fast radio bursts or FRBs (Fast Radio Bursts in English). An international team of researchers has just revealed the fastest and most distant ever detected, the origin of which is dizzying.
In an article published on October 19 in the journal Science, astronomers explain that they captured a rapid radio burst last June thanks to ASKAP, an Australian network of radio telescopes. This allowed them to “ determine the precise location from which the startle came “, explained Stuart Ryder, an astronomer at Macquarie University in Australia and co-lead author of the study.
The region it came from was then combed by the Very Large Telescope (VLT) of the European Observatory (ESO) in Chile. A radio signal of such power is indeed accompanied by an emission of light, but the latter is barely visible. And for good reason: it comes here from a galaxy so distant that the signal took eight billion light years to reach us.
To travel such a distance requires an insane amount of energy, of which once the journey is over there is almost nothing left. Thus, the power of fast radio bursts is in fact 1013 times greater than the total luminosity of the Sun. That’s many, many zeros for a phenomenon barely detectable to Earthlings.
A way to “weigh” the universe
The precise origin of these impressive signals “ probably due to the activity of neutron stars » estimates for the HuffPost Fabrice Mottez, astrophysicist at the CNRS and the Paris Observatory. But in any case, paper confirms that fast radio bursts are common events in the cosmos » remarks one of the authors of the study.
This discovery also confirms that these FRBs might make it possible to “ detect matter between galaxies, and better understand the structure of the universe “. Before reaching us, the wave travels between galaxies. On the road, ” it will encounter elements, notably electrons which wander through space, modifying the propagation of the wave » explains Fabrice Mottez. Basically, it’s a bit like when you try to speak in water, the sound is distorted. Same thing for the wave, the analysis of the distortion of which then allows us to better understand what is in the path of the wave, between the galaxies.
The idea is also to be able to estimate the mass of the universe. Currently, the methods used give contradictory answers. “ If we count the amount of normal matter in the Universe, namely the atoms of which we are all made, we find that more than half of what should be present today is missing. », Explains Ryan Shannon, one of the authors of the study. The missing part might then be hidden in the space between galaxies, and the propagation of fast radio bursts would then serve as a measuring tool to weigh this matter, and in fine our entire universe.
The only problem is that this new discovery marks the glass ceiling of current technologies: current instruments do not allow us to go back more than 8 billion light years. But new telescopes are being built, more sensitive, therefore capable of observing more distant sources. This is the case of the international Square Kilometer Array observatory, which is currently building two radio telescopes in South Africa and Australia. A more ambitious version of ESO’s Very Large Telescope, the Extremely Large Telescope, is also under construction.
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