Astronomers have detected the oldest black hole ever observed, dating back 13 billion years to the beginning of the universe.
Observations by the James Webb space telescope (JWST) revealed that it was at the heart of a galaxy 440 meters after the big bang. At around a million times the mass of the Sun, this mass is surprisingly large for a baby black hole, raising the question of how it grew so quickly.
Cambridge University astrophysicist Prof Roberto Maiolino, who led the observations, said: “The surprise is that it was so big. It was the most unexpected.”
The observations published on the preprint website Arxiv do not take a direct view; This is an image that cannot be seen because no light can escape from its grasp. But astronomers have detected telltale signs of the accretion disk, a halo of gas and dust rapidly swirling around the cosmic sinkhole.
Astronomers believe it could help solve the puzzle of how the oldest black holes, their massive counterparts at the centers of galaxies like the Milky Way, grew to be billions of times the mass of the Sun. Until recently, it was assumed that they grew steadily like a snowball over about 14 billion years, growing steadily through mergers and swallowing stars and other objects. But this snowball scenario can’t fully explain the epic proportions of today’s supermassive black holes.
Recent observations of the galaxy called GN-z11 trace the origins of this mystery back to the beginnings of black holes, suggesting that they were either born large or ballooned extremely quickly very early on.
Cosmologist Prof. from University College London, who was not involved in the research. “Understanding where black holes come from has always been a puzzle, but now that puzzle appears to be getting deeper,” said Andrew Pontzen. “Using the power of JWST to look back in time, these results show that some black holes grew at a tremendous rate in the young universe, much faster than we expected.”
One explanation, known as the heavy seed scenario, is that early-generation black holes were born from the direct collapse of vast clouds of gas, rather than burnt-out stars collapsing under their own gravity at the end of their lives. Another possibility is that clusters of compact stars and black holes merged very quickly in the early universe.
A third and more speculative hypothesis is the existence of so-called primordial black holes, which emerged during the cosmic inflation, the period in which the universe expanded faster than light, occurring a fraction of a second after the big bang.
This would reverse the supposed order of play, where galaxies arrive first and then black holes begin to grow inside them. Primordial black holes will be effectively woven into the fabric of the cosmos from the beginning.
“If this were true, it would have profound effects on the opening one-second portion of our universe,” Pontzen said. “Either way, the story of how black holes and galaxies grow together is a gripping story that we are just beginning to piece together.”
The findings are the latest in a series of striking discoveries made just two years after the launch of NASA’s space observatory. JWST is about 100 times more sensitive than previous telescopes like Hubble at detecting infrared light, the part of the spectrum used to see the most distant objects. “This is essentially equivalent to upgrading Galileo’s telescope to the modern telescope. JWST operations are potentially 400 years of discoveries compressed in time, Maiolino said.
He said there was a possibility that a new window would be opened “on a boring extension of what we know” before the telescope’s launch. “That’s not what we’re seeing,” Maiolino said. “The universe was very generous. “We encounter things that we really did not expect.”
What is a black hole?
Black holes are among the strangest and most sinister objects in the universe. They have such an intense attraction that neither matter nor light can escape from their grasp. The threshold of a black hole is determined by its event horizon, which is the point of no return. Everything that exceeds this limit disappears completely.
It’s hard to study them because they’re basically invisible, but applying the laws of physics offers some strange insights. As a black hole is approached, the gravitational gradient can be so extreme that objects can stretch out in a process known as spaghettification. At the event horizon, gravity is so intense that light bends to form a perfect loop around the black hole; This means that if you stand there you can see the back of your own head.
It is unknown what lies beyond the event horizon. Einstein’s theory of general relativity suggests that the density at the center of a black hole will become infinite, creating a gravitational singularity. This break in space-time will have no “where” or “when” and will lie beyond the laws of traditional physics. However, it is not clear whether such singularities actually exist.
Black holes come in various sizes. Stellar black holes, formed from the remnants of massive stars, can be 20 times more massive than our sun. Supermassive black holes, such as Sagittarius A* at the center of the Milky Way, can have masses equivalent to millions or billions of suns and play a crucial role in galactic evolution.
Astronomers have made significant advances in black hole observations over the past decade, with the first image of the halo captured by the Event Horizon telescope in 2019 and the observation of cataclysmic black hole mergers through the detection of gravitational waves sent rippling through space-time. . The latest observations and even more distant James Webb targets will begin to piece together the origins of these enigmatic objects.