Astrophysicists from Tohoku University in Japan have brought us a new theory which declares that supermassive black holes evolve not only by swallowing pristine gas clouds but also clouds containing heavier elements and small stars. This could be the explanation for the presence of a large number of supermassive black holes today.
Black holes are a mystery to every science lover or let’s say any individual with the tiniest interest in space. How are they formed? What happens if we fall inside them? How long does it take to make a black hole? etc.
Astrophysicists have been analyzing the formation of black holes for a very long time. The more they try to understand the more bizarre it gets. One popular theory that exists which explains the formation of supermassive black holes is the direct collapse model in which primordial gas clouds collapse under self-gravity to form supermassive stars which eventually evolve into a supermassive black hole. But this happens only with pristine gas, i.e gas containing no element heavier than hydrogen and helium. When heavier gasses like carbon and oxygen are present, the gas cloud splits violently and forms a large number of smaller stars rather than a few supermassive stars, which in turn prevents the formation of supermassive black holes. Therefore, there should be another explanation for the formation of these as almost every known galaxy has a supermassive black hole at its centre, with masses reaching 10 billion times the mass of the sun. Pristine gas clouds alone cannot solve the existing enigma of a large number of supermassive black holes observed today.
That is when, Sunmyon Chon, a postdoctoral fellow at the Japan Society for the Promotion of Science and Tohoku University along with his team generated long-term 3D high-resolution simulations with the help of a supercomputer named “ATERUI II” to test the possibility of formation of supermassive stars in high-element-enriched gas. These simulations were not easy to generate but were worth every penny of effort.
The researchers discovered that unlike it was believed, supermassive stars could indeed form from clouds of heavy elements. As expected, the gas cloud split violently forming a large number of small stars. But there was a huge gas flow towards the centre of the gas cloud which pulled these smaller stars along with it to the core, where massive stars gobbled them up. This composed a massive star 10,000 times more massive than the sun, at the centre of the gas cloud.
According to Chon, this giant star will continue to grow and evolve into a giant black hole. Thus from their research, it is observed that giant stars are not just formed from primordial clouds but also from clouds containing heavier elements, which will later evolve into giant black holes. Therefore supermassive black holes can also originate from high-element enriched clouds.
References: https://www.cfca.nao.ac.jp/en/pr/20200602
Author
