When the universe was around 500 million years old, this unusual black hole had already accumulated enormous mass. By analyzing its evolution, astronomers were able to draw conclusions about how such massive yet ancient objects arose in the early universe.

The Pandora Galaxy Cluster, or Abel 2744, is a huge galaxy cluster that scientists believe was formed by at least four galaxy clusters merging at the same time. While this object is interesting in itself, its properties are not the only reason astronomers are interested in it. Because of its mass, this cluster acts like a gravitational lens, giving us a magnified view of much more distant galaxies that cannot be seen with available instruments. Using the James Webb telescope and this galaxy cluster, he was able to find 11 such galaxies that formed less than a billion years after the Big Bang. An international team of astronomers decided to find out whether there are supermassive black holes at the centers of these objects that are actively absorbing matter. Such galactic nuclei are called quasars. Scientists used the Chandra X-ray Observatory because the processes that take place there emit strong X-rays.

The location of the bright source coincides with the galaxy UHZ1, which has been magnified by a factor of four by gravitational lensing. The galaxy is visible at a redshift of z ≈ 10.3, or 500 million years after the Big Bang. Judging by its energy content and wavelength, it has a quasar at its center, hidden by the galaxy’s dust and gas. But the most important thing here is its mass. Scientists estimate the mass of such an object based on its brightness. The more mass an object has, the more matter it absorbs, the brighter the matter shines, and the more it slows down before “falling” into the black hole. However, if the radiation is too strong, it will “blow away” surrounding matter like a wind, and the “food source” will disappear. The turning point in this process is called the Eddington luminosity or Eddington limit. According to the data obtained, the mass of UHZ1’s black hole is at least 10 million times that of the Sun. And their entire galaxy has about the same mass. No such celestial bodies exist in the modern universe. Typically, a supermassive black hole has a mass of about 0.1% of the mass of its galaxy. According to the study authors, such a high proportion of UHZ1 means humans “captured” this object at an early stage in its evolution.

There are two versions of how such huge objects formed in the early universe. The first theory is that the “seeds” in these holes are the remains of very massive early stars, which gained mass over time by absorbing material. According to the second version, they arose immediately and significantly during the gravitational collapse of cosmic gas clouds. Based on the estimated mass of quasar UHZ1 and assuming that the black hole was formed 200 million years after the Big Bang, scientists calculated its evolution and came to the following conclusion: If a hole were to form from a dead star, it would have to absorb material twice as fast as the Eddington limit would allow during evolution. If it’s originating from the cloud, keeping the speed within this limit is sufficient.

source: https://www.nature.com/articles/s41550-023-02111-9