Astronomers have discovered a tiny, super-massive black hole lurking in the center of a dwarf galaxy 340 million light-years away. And even if its dimensions are small, it can help solve the most complicated puzzles of black holes.
The black hole was found in the dwarf galaxy RGG 118, and today it is the smallest black hole we know, and yet its impressive mass is 50,000 times the mass of our Sun. However, it is still less than half the mass of the next smallest discovered supermassive black hole and 100 times less than the mass of a supermassive black hole located in the center of our galaxy.
Comparison results show that the RGG black hole is 200, 000 times smaller than the largest known supermassive black hole.
Even despite the size comparison, this newly discovered black hole is incredibly important for astronomers trying to understand the complex evolutionary processes that dominate the development of supermassive black stars located in almost all galaxies, as well as how they determine the evolution of the host galaxies.
Image of RGG 118
“It may sound controversial, but finding such a small, huge black hole is very important,” says Vivian Balthasar of the University of Michigan in Ann Arbor for a NASA news release. “We can use the observations of the lightest supermassive black holes to better understand how black holes of various sizes grow.” The RGG 118 was originally discovered by the Sloan Digital Celestial Survey project, and a team led by Balthazar used NASA’s Chandra X-ray Observatory and a 6.5-meter Magellan telescope in Chile to describe a surprisingly small supermassive black hole. They were able to visually examine the movement of cold gas in the center of the RGG 118 with the help of the Magellan telescope and to obtain a scale image of X-ray radiation from a hot swirling gas in the immediate vicinity of the black hole with the help of Chandra. Both means allowed to prove that the black hole of the galaxy RGG 118 behaves as well as other supermassive black holes in the centers of galaxies.
The speed of rotation of the stars surrounding the black hole in the heart of the galaxy also confirmed this discovery.
“We found that this small supermassive black hole behaves in the same way as its larger, and in some cases much larger, relatives,” added co-author Amy Reyns of the University of Michigan. “This tells us that black stars grow the same regardless of their size.”
One of the biggest secrets of modern astrophysics is the existence of a truly enormous, billions of times greater than the mass of the Sun supermassive black hole, which was supposed to exist in the universe less than a billion years after the Big Bang. Astronomers hope to restore the model of evolution through the discovery of this small instance of a black hole. At present, the theory says that supermassive black holes are formed either as a result of the rapid collapse of huge gas clouds, whose mass is 100,000 times the mass of our sun, or they appear as a result of the collapse of massive stars. Now we have the opportunity to find out which of these models is most likely on the example of the RGG 118.
“We are dominated by two ideas about how supermassive black holes are born,” says Elena Gallo, another researcher from the University of Michigan. “The black hole of the galaxy RGG 118 serves as a substitute for those holes that existed in the young universe, and as a result can help us to understand which of them is true.”