Rotation shapes the evolution of primordial stars
doi:10.1038/nindia.2016.18 Published online 10 February 2016
By using three-dimensional simulations, a researcher has gained new insights into how the initial degree of rotation of a collapsing gas cloud shapes the chemical and thermal evolution of primordial stars1. These stars are entirely made of gases such as hydrogen and helium and heavier elements such as lithium and beryllium. Knowledge of their evolution will help scientists better understand the era in which the Universe transitioned from a simple to a complex system.
To analyse the effects of rotation on a collapsing gas cloud in primordial stars, the researcher used a set of three-dimensional hydrodynamical simulations. He found that the cloud’s initial degree of rotation significantly impacts heating and cooling processes, leading to scatter in the temperature evolution of the collapsing gas. Clouds with slower rotations collapse faster. This compresses the clouds, heating them further.
The scientist also found that the dynamical evolution of the gas strongly depends on the initial degree of rotation. In the absence of initial turbulence and magnetic fields in the clouds, the rotation distribution leads to the formation of a disk that fragments into several clumps. The faster the rate of rotation is, the higher the formation of clumps known as protostars, which might fragment and survive to this day.
Simulating appropriate initial conditions of the gas cloud is a pivotal way to study the evolution and final fate of primordial stars, the researcher says.
1. Dutta, J. On the effects of rotation in primordial star-forming clouds. Astron. Astrophys. 585, A59 (2016)