E-Paper
In a strange discovery, scientists detect light behind black hole for first time
While the bright flares are not an unusual phenomenon, the X-rays reflecting from behind the black hole was a strange discovery.
Scientists have detected light from behind the black hole for the first time, confirming a scenario predicted by Einstein’s theory of general relativity. Stanford University astrophysicist Dan Wilkins and his colleagues were observing X-rays released by a supermassive black hole 800 million light-years away when the telescopes recorded additional flashes of X-rays smaller and of different colours than the bright flares.
“Any light that goes into that black hole doesn’t come out, so we shouldn’t be able to see anything that’s behind the black hole,” Wilkins, the author of the study, said in a statement.
While the bright flares are not an unusual phenomenon, the X-rays reflecting from behind the black hole was a strange discovery. Material falling into a supermassive black hole gets superheated due to the enormous gravity around it, powering continuous sources of light in the universe by forming corona.
Also Read | Researchers observe never before seen short gamma-ray burst from collapsing star
When the electrons separate from atoms at such a high temperature, a magnetic plasma is created. The magnetic field breaks as it arch high above the black hole and then bends towards it, producing high energy electrons that subsequently produce the X-rays. Researchers determined that the series of smaller flashes were the same X-ray flares but reflected from behind the black hole.
“I’ve been building theoretical predictions of how these echoes appear to us for a few years,” said Wilkins. “I’d already seen them in the theory I’ve been developing, so once I saw them in the telescope observations, I could figure out the connection.”
The study, published late last month in the journal Nature, is the first direct observation of light from behind a black hole.
"Fifty years ago, when astrophysicists starting speculating about how the magnetic field might behave close to a black hole, they had no idea that one day we might have the techniques to observe this directly and see Einstein’s general theory of relativity in action,” said Roger Blandford, a co-author of the paper.
