Astronomers identify the origin of an extraterrestrial signal emitted from 400,000 light years far in the constellation Grus
Astronomers have begun to have successes on one of the most mysterious phenomena of the known universe they have identified the origin of an extraterrestrial signal
An FRB can release as much energy in 1 millisecond as our sun in a century.
Called Fast Radio Bursts (fast radio bursts or FRBs), they last much less than a blink and are so mysterious that even the fantastic possibility that some of them are issued by an advanced civilization has been hinted at.(origin of an extraterrestrial signal)
The truth is that the origin of these very brief radio pulses, mere electromagnetic whispers when they reach Earth, is a real enigma. But the enigma could be resolved soon, as a recent finding seems to suggest.
An international team of astronomers has found the precise location of one of these powerful explosions. And it’s really far away: on the outskirts of a medium galaxy, the size of the Milky Way, located 4 billion light-years away from us. If the distance impresses, this data is not far behind: the explosion only happened once during a thousandth of a second.(origin of an extraterrestrial signal)
“This is the breakthrough we have been waiting for since the FRBs were discovered in 2007,” says Keith Bannister , of the Commonwealth Scientific and Industrial Research Organization (Australia). It was a new radio telescope of this organization, the ASKAP ( Australian Square Kilometer Array Pathfinder ), which detected the signal. Then, three of the largest optical telescopes in the world, the Keck in Hawaii and the Gemini South and the Very Large Telescope of the European Southern Observatory (ESO) in Chile, photographed the galaxy from which it comes.
In the 12 years since the first discovery, astronomers around the world have detected 85 of these explosions. Most have only occurred once, but a couple of them are repeaters. The source of one of these repeaters (FRB 121102) was located in 2017: more than 200 emissions that seem to arrive from a magnetar (a rotating neutron star) of only about 10 square kilometers located in a dwarf galaxy to 3,000 million light years of us.
A signal without repetition
But, as the authors of the study explain in the journal Science , the location of a single outbreak has been much more challenging. The FRBs last less than a millisecond, which is already a challenge for detection and tracking, and is more complicated when they shine and do not reappear.
Now, thanks to the use of a new technology to store ASKAP data, the Bannister team was able to point out in September 2018 the location of FRB 180924 on the outskirts of a galaxy the size of the Milky Way, some 3,600 light-years away. distance from its center. “If we stood on the Moon and looked at the Earth with this precision, we could say not only which city the explosion came from, but also which ZIP code, and even which block of the city,” the researcher says.
The Milky Way extending over the central group of ASKAP. © CSIRO, Alex Cherney.
ASKAP is formed by a series of multiple dish antennas and the rapid radio burst had to travel a different distance until each of them, reaching them at a slightly different time. “From these small time differences, only a fraction of a billionth of a second, we were able to identify the local galaxy of the explosion and even its exact starting point,” explains Adam Deller, of the Swinburne University of Technology. and team member.
To get more information about the local galaxy, the team photographed it with the Very Large Telescope and measured its distance with the 10m Keck telescope and the 8m Gemini South. The only previously located explosion, the “repeater,” comes from a very small galaxy that is forming many stars. However, the new signal and its galaxy do not resemble each other.
The intergalactic network
“It comes from a massive galaxy that is forming relatively few stars. This suggests that FRBs can be produced in a variety of environments, or that the seemingly isolated bursts detected so far by ASKAP are generated by a mechanism different from those that are repeated, “says Deller.
The cause of rapid radio explosions remains unknown, but the ability to determine their exact location is a great leap towards solving this mystery. “Like gamma-ray bursts two decades ago, or the most recent detection of gravitational wave events, we are at the height of a new and exciting era in which we are about to learn where rapid bursts of bursts occur. radio, “says team member Stuart Ryder of Macquarie University, Australia.(origin of an extraterrestrial signal)
According to Jean-Pierre Macquart of the International Radio Astronomy Research Center (ICRAR), “these outbursts are altered by the matter they find in space.” In this way, “now that we can identify where they come from, we can use them to measure the amount of matter in the intergalactic space.” This would help astronomers to know the material they have tried to locate for decades.