Almost 10 years ago when they were first detected, short radio bursts fascinated scientists.
This phenomenon is called Fast Radio Bursts or FRBs, it is very powerful and lasts only a few milliseconds. The way the frequencies are spread, suggests that the source of the signal is somewhere far outside our galaxy. Until now, around 18 such events were discovered, which were called by Nature, the “most perplexing mystery in astronomy.”
Scientists have been trying to figure out where they come from and why these bursts happen. But the researchers were able to highlight one of the FRB’s sources: a remote galaxy located billions of light-years away from Earth.
The fact that the source of this mysterious phenomenon has been located, it can provide clues to its cause, according to Shami Chatterjee, an astrophysicist at Cornell University.
Now you’re probably wondering: could the source be actually aliens? Chatterjee said that most likely … no. Among the most likely explanations include a neutron star or an active galactic nucleus core, although there are plenty of possibilities.
The story of this particular burst, which is called FRB 121102, took an unexpected turn when scientists have noticed that the signal kept repeating. At this time, a number of theories have been put aside on why this happens. For example, the theory of two neutron stars colliding, because that can’t be explosive.
The equipment used to detect FRBs is able to observe only a small portion of the sky at a given time. The fact that FRB 121102 keeps repeating has helped scientists to focus on those sections of the sky.
In 2015 the team began using a network of 27 radio dishes located in New Mexico, named a interferometer, which is able to detect these signals at a resolution higher than other units.
In the first 10 hours of observations, they have found nothing. They also recorded another 40 hours, and again, nothing. Unhappy with these results, the team enlisted the Arecibo Observatory in Puerto Rico.
And this time they were lucky. They managed to capture nine pictures of the radio bursts, which allowed the researchers to highlight a very small section of the sky from where they came.
In that very small section of the constellation Auriga, lies a small galaxy that’s just a fraction of ours, says Chatterjee, about 2.5 to 3 billion light years away. This great distance highlights the relativity of cathing the emitted signals, considering that what caused this event took place billions of years ago.
What is the cause of this phenomenon, anyway? Chatterjee says it could be several theories.
But the key question is different: do all FRBs repeat like this one or there are types that do not repeat?
“They’re probably the same thing and we haven’t been lucky enough to observe the other ones repeating, but if not, hey, great, nature’s given us two fantastic mysteries instead of one fantastic mystery.” says Chatterjee.