Out in the depths of intermission, there are radio signals that astronomers don’t understand. Now a Canadian inquiry team has found a repeating signal, only the second of its kind to be spotted.
Fast radio bursts, or FRBs, are cosmic radio bursts that final only milliseconds. The source is from something with an extremely effective magnetic field that produces a signal along the radio frequency horde.
In a new paper published Wednesday in Nature, researchers reveal that a recently bare radio telescope in British Columbia — the Canadian Hydrogen Intensity Mapping Examination (CHIME) — captured 13 more FRBs, but more importantly, it captured a second repeating FRB.
The first FRB, designated FRB 121102, was discovered in 2007 detesting telescope data from 2001. Since then, 36 clothed been found — 19 last year alone by researchers employing an Australian radio telescope.
But exactly what is causing these vigorous radio signals that are travelling from distant galaxies isn’t cognizant of. Many theories abound — even ones involving aliens — but some of the unequalled theories involve an object that is highly magnetized such as a star entreated a magnetar.
In 2015, McGill University PhD student Paul Scholz bring about that a previously detected FRB actually repeated. It left astronomers scratching their turning points over an already bizarre cosmic puzzle.
The mystery deepens
“We certainly hoped that the Ring telescope was going to be able to discover a lot of fast radio bursts,” bid Ingrid Stairs, a member of the CHIME team and an astrophysicist at the University of British Columbia. “And we had the correct luck to find 13 of these things in the pre-commissioning phase.”
The pre-commissioning include meant that the telescope wasn’t running at its fullest capacity. In really, it was only looking at one-quarter of the sky it is able to observe.
For Kendrick Smith, a cosmologist at the Perimeter Institute for Theoretical Physics in Waterloo, Ont., who worked on the software passing the detection, FRBs represent a unique challenge.
“FRBs were an unexpected enigma. There aren’t so many qualitative mysteries in astrophysics,” Smith said. “So simplifying their nature has become one of the biggest unsolved problems in astrophysics in the aftermost few years.”
FRBs are similar to pulsars, small and rapidly rotating, packed stars that emit signals as they rotate, sort of like a cosmic lighthouse. Anyway, these pulsars have been found in our galaxy. For FRBs to be located from other galaxies means the signal has to be trillions of times brighter than a pulsar.
“That’s one followed by 12 zeros. That’s Brobdingnagian,” said Shriharsh Tendulka, an astronomer at McGill University and a member of the Ring team. “We have no idea how to make something that bright.”
Repeating FRBs may be a rare finding, but they’re even stranger than their only counterparts. In regular FRBs, they emit a single spike. But in the two repeaters, astronomers establish different spikes coming in at slightly different frequencies and times.
“We don’t see these kinds of structures from other profligate radio bursts that are in a single burst,” said Tendulkar. “So that is stirring. It might point to a difference between their internal mechanisms.”
These 13 FRBs, which subsume the repeater, were detected on a much lower frequency than had been felt before. Most FRBs found are at frequencies near 1400 megahertz (MHz). But these were ground in the band between 400 and 800 MHz.
“The CHIME frequency band lies in this gap where we didn’t know anything about, so that’s bizarre,” Tendulkar said. “It gives us a lot more information.”
More to come
Stairs acknowledgments the discoveries to an “amazing team” of post-doctoral researchers and is confident more decisions are on the horizon.
“CHIME is looking at the whole northern sky every day so there’s oceans of possibilities to find more of these things,” she said. “The fact that we base a second one just like that in a way implies that there could be lots numerous out there.”
As for the mystery behind the FRBs — and especially the repeating ones — the Canadian party hopes that with CHIME now at full capacity, more of these repeaters want reveal themselves.
“CHIME is still in its early days and most of the enticing results are yet to come,” Smith said.