The black hole is located about 13.2 billion light-years away from Earth and must have formed shortly after the Big Bang. The black hole is still very young, but already bizarrely heavy; it is even more massive than the galaxy it is part of! And that’s something researchers haven’t seen before.
The discovery of this special black hole required not one, but two powerful telescopes. And even they could not actually discover the distant galaxy and the special black hole that resides in it on their own, as the magazine reports. Nature Astronomy to read. Fortunately, they got help from a cluster of galaxies called Abell 2744, located 3.5 billion light-years away from Earth. This cluster stands between us and the distant galaxy that is the focus of the new study and could therefore serve as a so-called ‘gravitational lens’. The light from the distant galaxy is deflected and amplified by the gravity of Abell 2744. And that lensing effect was just strong enough to make the distant galaxy visible to the James Webb telescope. Subsequently, the Chandra X-ray observatory – again thanks to that lens effect – detected the X-rays that revealed that a supermassive black hole could also be found in the galaxy (see box).
X-rays
Black holes are characterized by intense gravity, meaning nothing can escape their grasp. Not even light. This makes black holes completely dark and in fact invisible. But due to the impact they have on their environment, we can (sometimes) still detect them. In this case thanks to X-rays. This is caused by the black hole attracting gas. That gas will circle around the black hole before it disappears into the black hole. It becomes extremely hot and emits strong X-rays.
The black hole that scientists have discovered is located in a galaxy about 13.2 billion light-years away from Earth. Due to the time it takes for the light from this galaxy to reach us, we see the galaxy (and the black hole) as it looked 470 million years after the Big Bang.
Young and heavy
The black hole is still young. But judging by the brightness and energy of the X-rays that the black hole (indirectly) emits, researchers assume that it is already between 10 and 100 million times heavier than our Sun. This makes the black hole about as heavy as all the stars in its galaxy combined. That is special; Black holes at the centers of galaxies closer to us typically have a mass comparable to 0.1 percent of the mass of the stars in their galaxy.
The birth of a black hole
Astronomers find it extremely interesting that this young black hole in the very young universe is so much heavier. Previous observations have already shown that supermassive black holes could already be found in the young universe. But never before has such a massive black hole been observed so early in the history of the universe as the one that scientists have now spotted. “This is one of the most dramatic discoveries from the James Webb Space Telescope,” said Michael Strauss, professor of astrophysics at the Princeton University and not involved in the investigation. “This is the most distant, growing supermassive black hole known to date. And this really completely pulverizes the old record.”
So we already knew that supermassive black holes were formed shortly after the Big Bang. But now one has been found that must have seen the light of day very shortly after the Big Bang. And that could provide more insight into how such supermassive black holes emerged so soon after the Big Bang. There is still a lot of uncertainty about this. There are actually two possibilities. One: they are already born quite heavy, because they are formed when enormous gas clouds collapse. In that scenario you get newborn black holes that are between 10,000 and 100,000 times heavier than our sun. Two, they formed when the first stars exploded and were born quite small. In that scenario you get newborn black holes that are only between 10 and 100 times heavier than our sun, which must then have started growing.
Growing takes time
But that growth takes time. And with the discovery of a black hole that is record-breakingly far away and was already very massive just 470 million years after the Big Bang, researchers now appear to have found a supermassive black hole that simply hasn’t had time to grow, but has already been growing very rapidly. is big! It’s a bit like researchers have stumbled upon a 200-pound toddler. “The fact that we have finally discovered a black hole that was so big when the universe was so young tells us that this black hole must have been very big at its birth,” says researcher Andy Goulding.
Outsize Black Hole
The mass of the black hole, in combination with its young age and the amount of X-rays it (indirectly) emits, therefore hint that we are dealing with a so-called ‘Outsize Black Hole‘. The term was coined by theorists in 2017 to describe black holes that were created in the early universe by collapsing large gas clouds – and were therefore already large at birth. Until recently, their existence was just a hypothesis, but researcher Priyamvada Natarajan thinks that has now changed. “We think we have one of these for the first time Outsize Black Hole detected,” said researcher Priyamvada Natarajan. “And it is the best evidence yet that some black holes are formed from huge clouds of gas. For the first time, we are seeing a supermassive black hole in that short-lived stage – before it lags behind in growth – when it weighs about as much as the stars in its galaxy.”
Although this one black hole strongly suggests that some supermassive black holes in the early universe had an advantage and were already heavy at birth, more research is desperately needed. Only through more observations of black holes that were already large shortly after the Big Bang can researchers fully clarify the origins of the very first supermassive black holes. However, after these observations they are optimistic that it should be possible – with a combination of different telescopes and observatories – to find more of these overgrown, newborn black holes in the very young universe.
