National Astronomical Observatory of Japan | 2020 Jun 02
Computer simulations conducted by astrophysicists at Tohoku University in Japan, have revealed a new theory for the origin of supermassive black holes. In this theory, the precursors of supermassive black holes grow by swallowing up not only interstellar gas, but also smaller stars as well. This helps to explain the large number of supermassive black holes observed today.
Almost every galaxy in the modern Universe has a supermassive black hole at its center. Their masses can sometimes reach up to 10 billion times the mass of the Sun. However, their origin is still one of the great mysteries of astronomy. A popular theory is the direct collapse model where primordial clouds of interstellar gas collapse under self-gravity to form supermassive stars which then evolve into supermassive black holes. But previous studies have shown that direct collapse only works with pristine gas consisting of only hydrogen and helium. Heavier elements such as carbon and oxygen change the gas dynamics, causing the collapsing gas to fragment into many smaller clouds which form small stars of their own, rather than a few supermassive stars. Direct collapse from pristine gas alone can’t explain the large number of supermassive black holes seen today.
Sunmyon Chon ... and his team used the NAOJ's supercomputer “ATERUI II” to perform long-term 3D high-resolution simulations to test the possibility that supermassive stars could form even in heavy-element-enriched gas. Star formation in gas clouds including heavy elements has been difficult to simulate because of the computational cost of simulating the violent splitting of the gas, but advances in computing power ... allowed the team to overcome this challenge. These new simulations make it possible to study the formation of stars from gas clouds in more detail. ...
Supermassive Star Formation via Super Competitive Accretion
in Slightly Metal-Enriched Clouds ~ Sunmyon Chon, Kazuyuki Omukai
- Monthly Notices of the RAS 494(2):2851 (May 2020) DOI: 10.1093/mnras/staa863
- arXiv.org > astro-ph > arXiv:2001.06491 > 17 Jan 2020