An extremely high-energy jet of matter shot out of a supermassive black hole billions of light-years away is pointed at Earth, astronomers have found.
The discovery was described in a paper published in the journal Nature Astronomy. An international team of researchers have revealed the likely source of an incredibly bright flash resulting from a cosmic explosion that occurred in a distant corner of the universe.
The bright flash, which contains X-ray, radio and optical light signals, was first detected by astronomers at the Zwicky Transient Facility in California on February 11.
Follow-up observations of the signal—dubbed AT 2022cmc—using ground- and space-based telescopes by the international team, which included researchers from MIT and the University of Birmingham in the U.K., indicated that it is likely a jet of matter spewed out of a supermassive black hole estimated to lie around 8.5 billion light-years away.
The study suggests that the jet was produced when this distant black hole began devouring a nearby star that had strayed too close. As the black hole fed on the material of the star, it ejected a stream of particles traveling at close to the speed of light in the form of a jet, which appears to be pointed directly at our planet.
Astronomers describe the process of stars being torn apart by the extreme gravity of a supermassive black hole as "tidal disruption events" (TDEs). Such events have been detected before, but AT 2022cmc is the brightest and most distant on record.
One explanation for why such a distant event can appear so bright to our scientific instruments is that it is pointed straight at us. Technically, the scientists said the signal had undergone "Doppler boosting"—a process in which the apparent luminosity of matter emitted close to the speed of light is modified due to a variety of physical effects.
Prior to AT 2022cmc, scientists had only detected three other Doppler-boosted TDEs, making the latest event a particularly rare find.
"One of the interesting things about this TDE is that we only have three other events that have had jets like this to compare it to at all," Benjamin Gompertz, an assistant professor at the University of Birmingham and an author of the study, told Newsweek.
"It's very much a new phenomenon that we're getting to grips with. We can say confidently that it's the most distant one we've ever found, and it's the first time a jetted TDE has been discovered by an optical telescope," he said. "Previously these have been discovered in gamma-rays or X-rays—i.e. very high energy light. That's not to say it's not high energy though; at the time the X-rays were first found, they were brighter than the other three TDEs after accounting for distance."
Gompertz said it is hard to put into context how high-energy this cosmic flash was, but on average the TDE put out as much energy in one second as our sun does in a million years.
"That means that it outshone the light from the entire Milky Way galaxy by a factor of more than a thousand," he said.
In terms of size, the scientists think that the "face" of the jet, as presented to us on Earth, must have been about 100-1,000 times the distance between the Earth and the sun from side to side. The black hole itself must have been smaller than about 100 million suns, the scientists said, but it is not clear how big the star was.
The study was able to document the birth of the jet, with the researchers able to catch the event right at the beginning—perhaps within a week—of the black hole starting to feed on the star. The researchers say the findings could shed new light on how supermassive black holes feed and grow.
"One implication is that there should be lots more of these things to find," Gompertz said. "We hadn't had one since 2011, but that's likely more to do with not knowing how to spot them than there not having been any. Our modeling also suggested that the jet was carrying a lot more debris than we expected, which has implications for how black holes launch jets."
As for the TDE in question, which took place when the universe was just around a third of its current age, it is long over.
"The light we saw had been traveling for 8.5 billion years, so for anyone standing next to the black hole, the star and the jet are long gone," Gompertz said.
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Aristos is a Newsweek science reporter with the London, U.K., bureau. He reports on science and health topics, including; animal, ... Read more
