One of the most prominent results of the study is the hypothesis that black holes are the source of dark energy, which is produced when ordinary matter is compressed during the death and collapse of large stars.
Dark energy is one of the puzzling cosmic mysteries, and it is - according to cosmology - one of the hypothetical forms of energy that fills space, pushing the cosmic space itself to expand, and this causes galaxies to rush away.
Recently, 17 researchers from 9 countries, led by the University of Hawai'i and Imperial College London, studied the growth rates of supermassive black holes, which are located in the centers of A select group of galaxies 9 billion years old, searching for evidence that black holes are a potential source of dark energy.
According to the press release issued by the University of "Imperial College London" on February 15, measurements taken from those galaxies showed that black holes are growing more than expected, in addition to that their growth rate is consistent with the so-called "cosmological constant".
The cosmological constant is a number that Albert Einstein added to his equations in order to prevent the universe from expanding, because the man did not believe that the universe was expanding, and when the American astronomer Edwin Hubble showed that the cosmic space was expanding, Einstein retracted his opinion, saying that the cosmic constant was his "biggest mistake."
However, the cosmological constant returned again in the twenties and thirties of the last century, to find a place for itself in the equations indicating the existence of dark energy, which was built by the Russian cosmologist Alexander Friedman, to express a form of energy that increases as the size of space itself increases, which is the concept Which later turned into "dark energy".
With this discovery, this new evidence was described as the reason why supermassive black holes can be a source of dark energy, in a scientific paper published in The Astrophysical Journal Letters.
Study co-author Dr Dave Clements, from the University's Department of Physics, says scientists have come to a really surprising conclusion, and that as they begin to look at how black holes grow over time, they may have found the answer to one of the biggest problems in cosmology.
Co-author of the study Dr. Chris Pearson, from the STFC RAL Space research institute, said that if this theory is correct, it will revolutionize the entire cosmology, because it will mean finding a solution to the origin of the dark energy that was present. That has baffled cosmologists and theoretical physicists for more than 20 years.
In the 1990s, it was discovered that the expansion of the universe was accelerating, and the gravity between all the galaxies in the universe was supposed to slow the expansion, but that didn't happen.
Meanwhile, scientists hypothesized that "dark energy" is responsible for pushing galaxies apart with a force greater than gravity, including a type of energy sewn into the fabric of spacetime itself, called vacuum energy.
And this is where black holes have been a problem. It's hard to oppose their intense gravity, especially at their centers, where all matter seems to collapse into a "singularity" and fall into the center of the black hole.
According to the press release, the new result shows that black holes gain mass in a manner consistent with the energy they contain in a vacuum, providing a source of dark energy and solving the problem of black holes.
Black holes are very powerful cosmic entities, formed when the life of giant stars ends through a massive explosion called a "supernova", and when they are found in the centers of galaxies they are called supermassive black holes, and they contain millions to billions of times the mass of our sun inside them in a small space. Relatively speaking, which creates a very strong attraction.
Black holes can grow in size by accretion of matter, such as by swallowing stars that get too close, or by merging with other black holes.
To discover if these effects alone can explain the growth of supermassive black holes, the team looked at data spanning 9 billion years, and observed a particular type of galaxy called giant elliptical galaxies that evolved early in the universe and then went dormant and finished forming stars, leaving Too little material for the black hole at its center to collect, which means that any further growth cannot be explained by these normal astrophysical processes.
A comparison of distant galaxies (when they were young) with local elliptical galaxies (old and dead) also showed much greater growth than expected by accretion or mergers, as black holes today are 7 to 20 times larger than they were 9 billion years ago.
On the other hand, further measurements with related galaxy clusters at different points in the evolution of the universe show a good fit between the size of the universe and the mass of the black holes. They show that the measured amount of dark energy in the universe can be accounted for by the vacuum energy of a black hole. According to the study, the vacuum energy is related to the expansion of the universe, and its mass increases with this expansion.
"One of the most important findings of our study is that we suggest that black holes are the source of dark energy," said Duncan Farah, an astronomer at the University of Hawaii. "This dark energy is produced when ordinary matter is compressed during the death and collapse of large stars."