The origin of the enigmatic fast radio bursts (FRBs), which astronomers have been trying to explain for more than a decade, is closer to being understood after the detection of the first signal of its kind in the Milky Way.
Three studies published this Wednesday in the journal “Nature“detail the observation of one of those high-energy pulses produced by a magnetar, a type of neutron star with a powerful magnetic field, located in our galaxy.
The researchers believe this finding will help clarify how these events originate, which until now had only been detected in more distant regions of the universe and whose unusual nature has been the subject of all kinds of hypotheses.
Rapid radio bursts are sudden flashes that in just a fraction of a second can download more than a hundred million times the Energy generated by the Sun.
Since they were first detected in 2007, astronomers have identified numerous bursts from various parts of the universe, but their remoteness has so far made it difficult to decipher the mechanisms that cause them.
Among the various hypotheses that have been put on the table in recent years was the possibility that its origin was that of the neutron stars, the dense remnants of certain giant stars after their supernova explosion. The observations now detailed in “Nature” point in that direction.
“This discovery suggests that some of the bursts, and probably most of them, given how common these events are in the universe, originate in magnetars,” said Christopher Bochenek, of the California Institute of Technology.
On April 28, a Canadian (CHIME) and an American (STARE) observing project detected an FRB in the same region of the sky.
In a short period of 1 millisecond, the burst, identified as FRB 200428, emitted more energy in radio waves of which the Sun generates in half a minute.
Both teams coincide in pointing out the galactic magnetar SGR 1935 + 2154 as the origin of the signal, which was accompanied by an explosion of X-rays from the same source.
“When I looked at the data for the first time I froze, practically paralyzed with emotion, it took me a few minutes to recover,” Bochenek recalled.
The Chinese five hundred meter aperture FAST radio telescope contributed observations from the same magnetar to corroborate the possibility that this is the source of the blast.
Once there is evidence that magnetars can produce rapid radio bursts, scientists hope to study in depth what mechanisms they fire those sudden bursts of energy.
Most radio emissions in the universe are produced through a process known as synchrotron radiation, in which electrons that move in a disorderly manner inside gases interact with magnetic fields.
This phenomenon generates radio waves in the vicinity of supermassive black holes, supernova remnants, and clouds of hot gases inside galaxies.
Physicists suspect that the bursts emitted by magnetars can be produced when a large current of electrons moving in a coordinated manner interacts with the magnetic field of those bodies.