Supermassive black holes are now known to be present at the center of the most, if not all, galaxies. These cosmic titans have masses millions or even billions of times greater than the sun, but despite their enormous size, supermassive black holes, which are more common in the local universe and therefore more recent in cosmic history, don't pose a threat.
However, supermassive black holes become a problem when they are observed in the early universe and have masses that are comparable to billions of suns. This is due to the fact that supermassive black holes must possess a mechanism that permits them to rapidly accumulate mass and expand to such enormous sizes, yet all the currently known growth mechanisms imply that this process progresses too slowly for objects like these to have existed immediately after the Big Bang.
Regan uses a troubling analogy to convey the issue. It's comparable to observe a family going down the street with two six-foot teenagers and a six-foot toddler in tow. That is a slight issue—how did the child grow to be so tall? The same holds true for the universe's supermassive black holes. How did they become so big so fast?
The most remote and ancient supermassive black hole was found this year by the James Webb Space Telescope (JWST), which further complicated the situation. This black hole, which is at the center of the galaxy CEE RS 1019, is rather small for a supermassive black hole because it has a mass 9 million times that of the sun.
Even still, the fact that this black hole exists only 570 million years after the Big Bang casts doubt on hypotheses about how black holes form. And it wasn't only this 9 million solar mass black hole. The Cosmic Evolution Early Release Science (CEE RS) Survey, the observing effort that discovered this supermassive black hole, also discovered two other supermassive black holes that existed both 1 billion years and 1.1 billion years after the Big Bang.
According to a professor of the Canadian University of Western Ontario, "the constraints on our existing ideas become stronger with each new discovery." When supermassive black holes were discovered 800 million years after the Big Bang, scientists became concerned. The challenge is merely greatly heightened by CEE RS.
This puts extra weight on the quest for a mechanism to explain how they got there because it shows that supermassive black holes are not some cosmic rarity but rather prevalent in the relative infancy of the universe. With the except for of the hypothetical primordial black holes that remain from the Big Bang, there are three major types of black holes: stellar mass black holes, which have masses between 5 and 100 times that of the sun, intermediate-mass black holes, which have masses between 100 and 10,000 times that of the sun, and supermassive black holes, which have the aforementioned masses.
When the most massive stars, which have between 30 and 130 solar masses, run out of nuclear fusion fuel and are unable to support themselves against their own gravity, stellar-mass black holes are created. These stars' cores collapse as their outer layers are destroyed in massive supernova explosions, forming stellar-mass black holes, regions of space with a singularity—a point of infinite density—at their centers and an event horizon, where the gravitational pull is so strong that not even light can escape.
Supermassive black holes must form differently from stellar mass It is impossible for a star to be large enough to have the initial starting mass to lose mass as it evolves through phenomena like the supernova that occurs in conjunction with the gravitational collapse of the star and still leave behind a core massive enough to become a supermassive black hole. Supermassive black holes must form differently from stellar mass black holes.
Astronomers have long held the theory that supermassive black holes could begin their existence as "seed black holes" that are considerably smaller. When the galaxies these supermassive black holes reside in collide, they grow by first consuming matter and then merging with other black holes, providing therm with gas and dust to consume.
When cosmic seeds encounter large volumes of matter and voraciously feast on this stuff to quickly grow into supermassive black holes, stellar-mass black hole seeds may develop.
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