The CHIME radio telescope has detected more than 500 mysterious fast radio bursts in its first year of operation, astronomers have revealed.
Fast radio bursts, or FRBs, are radio emissions that appear momentarily and randomly from space, ranging from a fraction of a millisecond to a few milliseconds.
CHIME has nearly quadrupled the number of fast radio bursts detected so far, according to the CHIME Collaboration, which includes researchers at the Massachusetts Institute of Technology (MIT).
The telescope detected 535 new fast radio bursts during its first year of use, from July 2018 to July 2019.
CHIME (Canadian Hydrogen Intensity Mapping Experiment), located in British Columbia, Canada, has four 328-foot-long U-shaped cylinders, allowing it to detect signals from when the universe was between six and 11 billion years old.
The cause of FRBS, which can generate as many as 500 million suns in just milliseconds, has continued to elude scientists
The scientists collected the new signals in the telescope’s first FRB catalog, which they will present this week at the American Astronomical Society Meeting.
“Before CHIME, there were fewer than 100 FRBs discovered in total — now, after a year of observation, we’ve discovered hundreds more,” said CHIME member Kaitlyn Shin, a graduate student in MIT’s Department of Physics.
“With all these resources, we can really get a sense of what FRBs look like as a whole, what astrophysics make these events possible and how they could be used to study the universe in the future.”
Calvin Leung, also a researcher at MIT, said there is much more recent data to dig through that comes from after the first year of CHIME’s operation.
Processing the data is quite time-consuming, he said, but this is likely to reveal more FRBs.
The average number of FRBs detected each day the telescope rotates is about two, he added.
“We work shifts to keep an eye on the telescope, and I think my personal best is four hours a night.”
FRBs – described as “short and mysterious beacons” – have been observed in different and distant parts of the universe, as well as in our own galaxy.
Their origin is unknown and their appearance is unpredictable.
WHAT IS THE WALKWAY TELESCOPE?
Image provided by the Canadian Hydrogen Intensity Mapping Experiment collaboration shows the CHIME radio telescope
The Canadian Hydrogen Intensity Mapping Experiment (Chime) is a radio telescope in Canada.
£12.2 million ($16 million) in funding, CHIME is located in the mountains of British Columbia’s Okanagan Valley at the NRC’s Dominion Radio Astrophysical Observatory near Penticton.
It contains four U-shaped cylinders 100 meters long (328 feet), which allows it to detect signals from when the universe was between 6 and 11 billion years old.
With its U-shaped metal mesh cylinders, the experts have compared it to the halfpipes used by snowboarders and skateboarders.
CHIME is a stationary array, with no moving parts. The telescope receives radio signals from half the sky every day as the Earth rotates.
While most radio astronomy is done by spinning a large saucer to focus light from different parts of the sky, CHIME stares motionless at the sky.
It focuses incoming signals using a correlator – a powerful digital signaling processor that can process massive amounts of data, at a rate of about 7 terabits per second, which is equivalent to a few percent of the world’s Internet traffic.
“Digital signal processing allows CHIME to simultaneously reconstruct and ‘look’ thousands of directions,” said Kiyoshi Masui, an assistant professor of physics at MIT.
‘That helps us detect FRBs a thousand times more often than a traditional telescope.’
The unique design, coupled with advanced computing power, will serve as a ‘time machine’ for looking deep into the history of the universe.
CHIME collects radio waves with wavelengths between 37 and 75 centimeters.
Most of these signals come from the Milky Way, but some began their journey billions of years ago.
When the scientists mapped the locations of the 535 FRBs, they found that they were evenly distributed in space and appeared to come from all parts of the sky.
From those that could detect CHIME, the scientists calculated that FRBs bright enough to be seen through a telescope like CHIME occur at a rate of about 9,000 per day across the entire sky.
“That’s the beauty of this field: FRBs are really hard to see, but they’re not uncommon,” said Kiyoshi Masui, an assistant professor of physics at MIT.
“If your eyes could see radio flashes the way you can see camera flashes, you’d see them all the time if you just looked up.”
The newly discovered FRBs seem to fall into two different classes: those that repeat and those that don’t.
Scientists identified 18 FRB wells that burst repeatedly, while the rest appear to be one-off.
The repeaters also look different, with each burst taking a little longer and transmitting more focused radio frequencies than bursts of single, non-repeating FRBs.
These observations strongly suggest that repeaters and one-time objects arise from separate mechanisms and astrophysical sources.
As radio waves travel through space, any interstellar gas or plasma along the way can distort or scatter the wave’s properties and trajectory.
The extent to which a radio wave is spread can provide clues as to how much gas it has passed through and possibly how much distance it has traveled from its source.
For each of the 535 FRBs CHIME detected, Masui and colleagues measured its distribution and found that most of the eruptions likely originated from distant sources in distant galaxies.
Artist’s impression of FRBs of a magnetar – stellar remnants with some of the most intense magnetic fields in the universe
The fact that the eruptions were bright enough to be detected by CHIME suggests that they must have been produced by extremely energetic sources.
As the telescope detects more FRBs, scientists hope to pinpoint exactly what kinds of exotic phenomena can generate such ultra-bright, ultra-fast signals.
Scientists also plan to use the eruptions and their distribution estimates to map the spread of gas throughout the universe.
“Each FRB gives us some information about how far they have spawned and how much gas they have propagated,” Shin said.
‘With large numbers of FRBs, we can hopefully find out how gas and matter are distributed on a very large scale in the universe.
“So beyond the mystery of what FRBs themselves are, there is also the exciting potential for FRBs as powerful cosmological probes in the future.”
FAST RADIO BURSTS ARE SHORT RADIO EMISSIONS FROM SPACE WHOSE ORIGIN IS UNKNOWN
Fast radio bursts, or FRBs, are radio emissions that appear momentarily and randomly, making them not only hard to find, but also difficult to study.
The mystery stems from the fact that it is not known what could cause such a short and sharp eruption.
This has led some to speculate that they could be anything from colliding stars to artificially created messages.
Scientists looking for fast radio bursts (FRBs) that some believe are signals sent by aliens could happen any second. The blue dots in this artist’s impression of the filamentary structure of galaxies are signals from FRBs
The first FRB was noticed in 2001, or rather “heard” by radio telescopes, but was not discovered until 2007 when scientists analyzed archival data.
But it was so temporary and seemingly random that it took astronomers years to agree that it wasn’t a malfunction of any of the telescope’s instruments.
Researchers at the Harvard-Smithsonian Center for Astrophysics point out that FRBs could be used to study the structure and evolution of the universe, whether or not their origins are fully understood.
A large population of distant FRBs could act as probes of material over vast distances.
This intervening material obscures the signal from the cosmic microwave background (CMB), the leftover radiation from the Big Bang.
A careful study of this intervening material should provide a better understanding of the fundamental cosmic constituents, such as the relative amounts of ordinary matter, dark matter and dark energy, that influence how fast the universe is expanding.
FRBs could also be used to detect what broke down the ‘mist’ of hydrogen atoms that permeated the early Universe into free electrons and protons as temperatures cooled after the Big Bang.