The mystery of young stars near the black hole

The mystery of how young stars can form under the massive gravity of black holes has been revealed by a group of astrophysicists at St Andrews and Edinburgh universities.

A team of researchers discovered this mystery after developing a computer that modeled giant gas clouds sucked into black holes. This study helps scientists in understanding the origin of stars as well as the supermassive black holes in our galaxy and the universe. The new discovery is published in Science magazine on August 22, 2008.

Until now, scientists have yet to explain how stars form around black holes, because molecular clouds - where stars form - are torn apart by massive gravity. .

However, new research by Professor Ian Bonnel (St Andrews) and Dr. Ken Rice (Edinburgh) found that stars appear from an elliptic plate, the remaining trace of a giant gas cloud is broken when encountering a hole. black.

The discovery of hundreds of large-sized young stars forming an oval orbit around a black hole 3 million times more massive than the sun at the center of our galaxy is the most remarkable recent discovery in the industry. celestial physics.

Professor Bonnel said: 'This model shows that a young star can form around a supermassive black hole if there is a reasonable supply of gas clouds located in the farther part of the galaxy.'

This model, implemented on the SGI Altix supercomputer of the Scottish Union of Universities of Physics (SUPA) - for over a year of computer time - tracks the development of two giant-sized gas clouds 100,000 times the size of the sun as they fall towards the supermassive black hole.

The molecular cloud is like the sun falling towards the black hole.(Photo: Science and Technology Council)

The model describes how clouds break down by the massive gravity of a black hole. Broken clouds form a spiral as they move around the orbit of a black hole; The spiral model removes the energy moving from the gas near the black hole to the gas outside. This phenomenon allows part of the cloud of gas to be sucked by a black hole while the rest escapes. Under such conditions, only large stars are formed , they inherit eccentric orbits of gas disks. The result matches the first two properties of young stars in the center of our galaxy: large size and eccentric orbits around the supermassive black hole.

Dr. Rice commented: 'The decisive factor is modeling the warming and cooling of the gas because this tells us the size needed for a portion of the gas to have enough gravity to overcome the gas pressure of the plate. coal, then how did that form. The warming process is due to the extreme pressure of the cloud when it is compressed and broken by a black hole. The phenomenon is balanced by the cold process, which requires detailed knowledge of the cloud's radiation release speed. '

Dr. Bonnel concluded: 'Stars around the galaxy's supermassive black hole are relatively short, about 10 million years, suggesting that this process may be repeated. The fact that stars are born around the black hole regularly, and a large amount of gas is directly attached to the black hole can help us understand the origin of the supermassive black hole in our galaxy and other galaxies. in the universe'.

Council of Science and Technology (SFTC) partially funded the research.