Radio explosion from Milky Way may help solve cosmic mystery

Radio explosion from Milky Way may help solve cosmic mystery

Astrophysicists have detected a burst of cosmic radio waves within our solar system for the first time and identified its origin, according to research published Wednesday that sheds new light on one of the mysteries of the Universe.

The origin of powerful fast radio bursts (FRB), intense flashes of radio emission that only last a few milliseconds, have baffled scientists since they were first detected just over a decade ago.

They are typically extragalactic, which means they originate outside our galaxy, but on April 28 of this year, several telescopes detected a bright FRB from the same area within our Milky Way.

Importantly, they were also able to pin down the source: galactic magnetar SGR 1935 + 2154.

Magnetars, young neutron The stars, which are the most magnetic objects in the universe, have long been prime suspects in the search for the source of these radio bursts.

But this discovery marks the first time astronomers they have been able to trace the signal directly to a magnetar.

Christopher Bochenek, whose Survey for Transient Astronomical Radio Emission 2 (STARE2) in the US was one of the teams that detected the explosion, said that in about a millisecond the magnetar emitted as much energy as the Sun radio waves do it in 30 seconds.

He said the burst was “so bright” that theoretically if you had a recording of the raw data from your mobile phone 4G LTE receiver and knew what to look for, “you may have found this signal that reached the middle of the galaxy” in the phone data.

This energy was comparable to FRBs from outside the galaxy, he said, reinforcing the argument that magnetars are the source of most extragalactic explosions.

Up to 10,000 FRBs can occur every day, but these high-energy surges were only discovered in 2007.

They have been the subject of heated debate ever since, with even small steps towards identifying their origin sparking great enthusiasm for astronomers.

One problem is that momentary flashes are difficult to locate without knowing where to look.

Theories of its origins have ranged from catastrophic events such as supernovae, to neutron stars, which are superdense stellar fragments formed after the gravitational collapse of a star.

There are even more exotic explanations, discarded by astronomers, for the extraterrestrial signals.

‘Key puzzle’
The latest discovery, which was published in three papers in the journal Nature, it was made by putting together observations from space and ground telescopes.

Both STARE2 and the Canadian Hydrogen Intensity Mapping Experiment (CHIME) detected the flare and attributed it to the magnetar.

Later that day, this region of the sky came into view of the extremely sensitive Five Hundred Meter Aperture Spherical Telescope (FAST) in China.

Astronomers were already monitoring the magnetar, which had entered an “active phase” and was firing X-rays and gamma rays, according to Bing Zhang, a researcher at the University of Nevada and part of the team reporting on the discovery.

FAST did not detect the FRB itself, but it did detect multiple X-ray bursts from the magnetar, he said at a news conference, raising new questions about why only one of the bursts was linked to an FRB.

In a Nature comment, Amanda Weltman and Anthony Walters, from the University of Cape Town High Energy Physics, Cosmology and Astrophysics Theory Group, said that the FRB’s link to a magnetar “potentially solves a key puzzle.”

But they said the findings also open up a range of new questions, including what mechanism would produce “such bright, but rare, radio bursts with their X-ray counterparts.”

“One promising possibility is that a flare from a magnetar collides with the surrounding medium and thus generates a shock wave,” they wrote, adding that the findings highlight the need for international cooperation in astronomy and monitoring of different kinds. of signals.

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