Found in the center of many galaxies.Giant black holeIts origin is shrouded in many mysteries. Years of research have led to the idea that supermassive black holes are formed by growth from smaller black holes, but the black hole “seed” is the result of the gravitational collapse of a star. (※1) There have been two conflicting theories: one that it is a light black hole created by Earth, and the other that it is a heavy black hole created by the gravitational collapse of a giant gas cloud in the early universe. .
*1…The condition in which gravity becomes so strong that it cannot be counteracted by other forces (such as electromagnetic interaction or dissolution pressure) and collapses indefinitely is called gravitational collapse.
A research team led by Andy D. Golding of Princeton University studies quasars, which have long attracted attention. (※2) 「Ultra frequency -1It was observed using the James Webb Space Telescope and detailed data were obtained. The results revealed that UHZ-1 is a galaxy that existed about 460 million years after the birth of the universe, and that the mass of the black hole at its center is 10 to 100 million times the mass of the Sun. This discovery is not limited to the supermassive black hole only;Supports the theory that the seeds of supermassive black holes are generated by the gravitational collapse of giant gas cloudssomething.
*2…Quasars are celestial objects that are believed to have a supermassive black hole at their center due to their energetic activity, and are also believed to be the early form of galaxies. Some sources refer to UHZ-1 as an active galactic nucleus (AGN), but since they have almost the same structure, this article classifies UHZ-1 as a quasar.
■ What is the “seed” of a supermassive black hole?
At the center of many galaxies, including our own Milky Way, is a galaxy with a mass of millions to tens of billions of the masses of the Sun.Giant black hole(A supermassive black hole)” exists. The process of gravitational collapse of a star’s core, which is known as the formation of black holes, is calledStellar black hole(Stellar-mass black holes) have a mass of only several to tens of times the mass of the Sun, so there is a significant difference in size from supermassive black holes.
How supermassive black holes form is a big mystery. When we observe the distant universe, that is, the early universe, we find thisQuasarSupermassive black holes are thought to have formed rapidly, shortly after the birth of the universe.
So how are supermassive black holes created? Years of research have shown that the most likely scenario is that the supermassive black hole is a much smaller black hole whose mass increased by absorbing gas. In this case,The origin of black holes that serve as the “seed” to grow into supermassive black holesIs this a problem.
There are two theories regarding “species” that are promising in research so far. The first theory is that black holes formed from extremely massive stars that existed at the beginning of the universe. In this case, the initial mass would be very small, 10 to 100 times the mass of the Sun. This theory stems from the well-known scenario of a star’s gravitational collapse, so many details are known. However, there is also the problem that no matter how fast they grow, they take hundreds of millions of years to grow, and some quasars exist in the early universe, which is too early for this scenario.
The second is “Direct collapse of a black holeThe theory is that it is a black hole called a “direct collapse black hole.” It is believed that at the beginning of the universe there were very large and dense gas clouds, which could collapse under the influence of their own gravity and form black holes. In this case, a black hole with a mass of up to 100,000 times the mass of the Sun is created, which far exceeds the maximum mass of stars. This theory is characterized by the formation of a massive black hole at a faster speed than the first theory. However, on the other hand, in order to create an environment where a massive gas cloud could generate a massive black hole, several stringent conditions must be met, and it is unclear whether or not there are many gas clouds that meet these conditions.
The most distant supermassive black hole discovered in “UHZ-1”
The research team led by Golding and his colleagues discovered the quasar.”Ultra frequency -1Search has been done. UHZ-1 had already been observed by NASA’s Chandra X-ray Observatory (National Aeronautics and Space Administration), and although it was viewed as an interesting object, there was still a lack of data for detailed investigation, such as resolution and resolution limits. distance.There was a problem with the lack of.
Golding and his colleagues observed UHZ-1 using the Webb space telescope, collecting and analyzing detailed data. As a result, the redshift of UHZ-1 was measured as z = 10.073 ± 0.002. This is 13.32 billion years old, located 31.5 billion light-years from Earth.460 million years after the birth of the universeThis means that a celestial body was present in (※3) .
*3…The distances between celestial bodies in this article are values based on “transmission distance,” which takes into account that the space in which light travels has expanded due to the expansion of the universe. On the other hand, the simple multiplication of the time the light travels is called the “light travel distance” (or optical path distance). In addition, due to the confusion caused by having two ways of expressing distance, and different interpretations of the numerical values required for distance calculations, there is a common method used to express the distance of distant celestial bodies and the era that was present in the papers. “Red shift (z symbol)” is used.
UHZ-1 emits energy of 5 x 10 to the power of 38 J per second, and from thisUHZ-1 contains a black hole with a mass between 10 million and 100 million times the mass of the Sun.This is what he estimatedDiscovery of the most massive supermassive black hole ever observedHe is.
In addition, the total mass of stars belonging to UHZ-1 is estimated to be about 140 million times the mass of the Sun, and the masses of UHZ-1 stars and supermassive black holes are almost the same, which means that black holes account for a very large proportion. A large proportion, this indicates that it is a long galaxy. This extreme ratio fits well with the situation in which a black hole arises as a result of the gravitational collapse of a massive cloud of gas.
We also found that the UHZ-1 observational data differ from typical quasars and active galactic nuclei. This is consistent with the black hole in UHZ-1 being hidden by dense dust and star formation.
■The Webb Space Telescope is revealing the secrets of the early universe one by one
These observational data from UHZ-1 are a discovery that raises the possibility that supermassive black holes are “seeds” of black holes generated by the gravitational collapse of gas clouds. However, there are still many mysteries surrounding the early universe, and observations by the Webb Space Telescope, which is said to help solve these mysteries, have only just begun. More research, including UHZ-1 observational data, is important to answer the ultimate question of what the early universe looked like.
Written by Riri Aya