Black holes, some of the most mysterious objectsin the universe, come in different sizes. What this or that space monster will be depends on the mass of the star at the last stage of its evolution. A new study has shown that a medium-mass black hole is the missing link between two other types of black holes - supermassive, which lurk in the centers of galaxies, and black holes, which are often formed when massive stars explode in the form of supernovae. Astronomers believe that the observable universe is full of medium-sized black holes, but finding them is not easy at all. But recently, astronomers were lucky and they managed to find the so-called "goldilocks" - a long-awaited object that can not be called either a supermassive or an ordinary black hole. The mass of the discovered object, as the authors of the scientific work write, is halfway between two other types of black holes. But why do researchers argue that goldilocks can change our understanding of the universe?
Massive space objects
Black holes are famous for devouring everything thatcomes too close, including the quanta of the light itself. Those of them that revolve in the centers of galaxies have an incredible mass - one of the largest black holes discovered to date has a mass of 40 billion suns, and its diameter exceeds 200 billion kilometers. Just imagine with what power this space monster absorbs everything that has the imprudence to be nearby.
It is interesting that all the inhabitants of space are different.Supernovae, dwarfs, neutron, cold - there are a great many types of stars in the observed Universe alone. As, however, and the planets outside our solar system - to date, discovered more than 400. Many of these distant worlds are gas giants, but there are those that are like two drops of water similar to the Earth. Asteroids, comets, galaxies and black holes are all different too.
Researchers estimate that everything in the vicinityIn the Milky Way galaxy, there are about 46,000 medium-sized black holes. In a new article published in the journal Nature Astronomy, scientists have found evidence of the existence of one such object. Note that the discovery of an intermediate black hole may shed light on the main question of modern astrophysics: how are supermassive black holes formed?
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Intermediate black holes
Scientists call intermediate black holesobjects whose mass is significantly greater than the mass of an ordinary black hole, but much less than that of a supermassive black hole. It is assumed that these objects in the vastness of the Universe are much smaller than other types of black holes, but evidence of their existence has not yet been found, since they are not easy to observe. Judge for yourself - they are not preceded by a supernova explosion, as is often the case with ordinary black holes. They are also smaller and less active than supermassive black holes, with less gravitational pull. This means that in order to truly see an intermediate black hole, one must look for the effects it can have on its environment.
First evidence of existence"Goldilocks" came to Earth in the form of light distorted by the Big Bang when the universe was just being born. In the course of the work, scientists scanned information about thousands of bursts caused by collapse or merging of stars, in the hope of using one of them to look into the early universe.
Recall that astronomers can look into the distant past using gravitational lensing - one of the most interesting spaceeffects that are capable of causing almost all large objects in the Universe. Gravitational lensing is observed when such an object receives light from explosions and distorts it like a lens, creating multiple images observed at different times.
As astrophysicists found out during their work, one ofof the detected bursts, apparently, was subjected to gravitational lensing by an object whose mass was several tens of thousands of times greater than the mass of our Sun. This suggests that, most likely, the lensing was caused by one of the medium-mass black holes - these are the objects that scientists have been looking for for many years.
“A newly discovered black hole could bean ancient relic - a primitive black hole that formed in the early Universe before the first stars and galaxies were formed, "- said study co-author Eric Train from the School of Physics and Astronomy at Monash University in an interview with Britain's The Independent.
See also: Astronomers have discovered a "wandering" black hole
If the object discovered by astrophysicistsis indeed an intermediate black hole, then in the near future scientists will be able to estimate the number of such objects in the observable universe. Note that physicists first predicted the existence of intermediate black holes more than thirty years ago.
The discovery could also explain the mysterious growth of supermassive black holes like the one at the center of our galaxy.
“Although we know that these supermassive blackholes lurk in the cores of most, if not all galaxies, we do not understand how these monsters can grow so large in all the time since the birth of the universe. If we knew how many there are, it would help to get better information about how these space monsters form and evolve over time, "- the words of the lead author of the study, graduate student of the University of Melbourne James Painter quoted Space.com.
It should also be noted that in addition togravitational lensing, there are other ways to detect intermediate black hole candidates. For example, in 2020, NASA reported a similarly sized intermediate black hole (50,000 mass that of our Sun) that became the source of an X-ray burst after a star that came too close to it was torn apart.
You might be wondering: How do astronomers listen to space?
And in 2019, astronomers discovered a signalgravitational wave (GW190521) from the merger of two black holes. The merger led to the formation of a more massive black hole, which, with its 142 solar masses, is also considered intermediate.