Scientists have discovered the oldest black hole ever observed, a cosmic monster that formed just 470 million years after the Big Bang.
The results published Monday confirm theories that supermassive black holes existed at the beginning of the universe. NASA’s James Webb Space Telescope and the Chandra X-ray Observatory teamed up last year to make these observations.
Since the universe is 13.7 billion years old, the age of this black hole is therefore 13.2 billion years.
Even more surprising to scientists: This black hole is huge: it is ten times larger than the black hole in our Milky Way.
It is thought to weigh between 10 and 100% the mass of all stars in its galaxy, said lead author Akos Bogdan of the Harvard-Smithsonian Center for Astrophysics. That number is a far cry from the tiny proportion of black holes in our Milky Way and other nearby galaxies, estimated at 0.1%, he noted.
“It’s really very early in the universe to be such a juggernaut,” said Priyamvada Natarajan of Yale University, who was involved in the study published in the journal Nature Astronomy.
A supplementary article was published in Astrophysical Journal Letters. “It’s amazing that this thing and its galaxy are present so early in the universe. »
Detected with X-rays
Researchers believe that the black hole formed from huge clouds of gas that collapsed into a galaxy next to another galaxy with stars. The two galaxies merged and the black hole took over.
The fact that Chandra discovered it using X-rays “confirms without a doubt that it is a black hole,” according to Ms. Natarajan. With X-rays, “you actually capture the gas that is gravitationally attracted to the black hole, which accelerates and starts to glow in the X-rays,” she explained.
This quasar is considered a quasar because it is actively growing and the gas is blindingly bright, she added.
The Webb Telescope alone may have discovered a black hole that is only 29 million years old, scientists say, but it has yet to be observed and verified in X-rays. Ms. Natarajan expects more early black holes to be discovered, perhaps less distant but still quite distant.
“We expect a new window to open in the universe, and I think this is the first rift,” she said.
The two space telescopes Webb and Chandra used a technique called gravitational lensing to magnify the region of space in which this galaxy UHZ1 and its black hole are located. The telescopes used light from a much closer galaxy cluster, just 3.2 billion light-years from Earth, to magnify UHZ1 and its black hole much further into the background.
“It’s a pretty flimsy object and luckily nature made it bigger for us,” Ms Natarajan said.
Launched in 2021 at a distance of 1.6 million kilometers, Webb is the largest and most powerful astronomical observatory ever launched into space. he sees the universe in the infrared. The much older Chandra Observatory sees X-rays; it was launched into orbit in 1999.
“I find it absolutely incredible that Chandra can make such amazing discoveries 24 years after its launch,” Bogdan said.