Radio burst from within Milky Way may help solve cosmic mystery
Astrophysicists have detected a burst of cosmic radio waves within our galaxy for the first time and identified its source, according to research published on Wednesday in the journal Nature, that sheds new light on one of the mysteries of the Universe.
The origin of powerful fast radio bursts (FRBs) - intense flashes of radio emission 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 originate 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 magnetar.
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 Sun’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 halfway across the galaxy” in the phone data. This energy was comparable to FRBs from outside the galaxy, he said, strengthening the case for magnetars to be the source of most extragalactic bursts.
As many as 10,000 FRBs may occur every day, but these highenergy surges were only discovered in 2007. Theories of their origins have ranged from catastrophic events like supernovas, to neutron stars, which are super-dense stellar fragments formed after stars collapse.