ASTROPHYSICISTS detect radio waves within solar system. Radio burst from within the Milky Way may help solve cosmic mystery.
PARIS : Astrophysicists have detected a burst of cosmic radio waves within our solar system for the first time and identified the source, according to research published Wednesday that sheds new light on one of the mysteries of the Universe.
The origin of a powerful fast radio bursts [FRBs] - intense flashes of radio emissions that only last a few milliseconds - have puzzled scientists since they were first detected a little over a decade ago.
They are typically extragalactic, meaning they originated outside our galaxy, but on April 28 this year, multiple 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 stars that are the most magnetic objects in the universe, have long been prime suspects in the hunt for the source of these radio bursts.
But this discovery marks the first time that astronomers have been able to directly trace the signal back to a magnestar.
Christopher Bochenek, whose Survey for Transient Astronomical Radio Emission 2 [STARE2] in the US was one of the teams to spot the burst, said that in approximately a millisecond the magnetar emitted as much energy as the Suri's radio waves do 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's 4G LTE receiver and knew what to look for, 'you might have found this signal that came about half-way across the galaxy in the phone data.
This energy was comparable to FRBs from outside this galaxy, he said, strengthening the case for magnetars to be the source of most galactic bursts.
As many as 10,000 FRBs may occur every day, but these high energy surges were only discovered in 2007.
They have been the topic of heated debate ever since, with even small steps towards identifying their origin stirring major excitement One problem is that the momentary flashes are difficult to pinpoint without knowing where to look.
Theories of their origin have ranged from catastrophic events like supernovas, to neutron stars, which are super-dense stellar fragments formed after the gravitational collapse of a star.
There are even more exotic explanations - discounted by astronomers - of extra terrestrial signals.
In a Nature commentary Amanda Weltman and Anthony Walters, from the High Energy Physics, Cosmology and Astrophysics Theory Group at the University of Cape Town, said the link of the FRB 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, yet rare, radio bursts with X-ray counterparts?
''One promising possibility is that a flare from a magnetar collides with the surrounding medium and thereby generates a shock wave,'' they wrote, adding that the findings highlights the need for international cooperation in astronomy and the monitoring of different types of signals. [AFP]
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