What is the Role of Gravity, Turbulence and Magnetic Fields in High-mass Star Formation Clouds?
An-Xu Luo, Hongli Liu, Guang-Xing Li, Sirong Pan, Dongting Yang
Abstract
Abstract To explore the potential role of gravity, turbulence and magnetic fields in high-mass star formation in molecular clouds, this study revisits the velocity dispersion–size ( σ – L ) and density–size ( ρ – L ) scalings and the associated turbulent energy spectrum using an extensive data sample. The sample includes various hierarchical density structures in high-mass star formation clouds, across scales of 0.01–100 pc. We observe σ ∝ L 0.26 and ρ ∝ L −1.54 scalings, converging toward a virial equilibrium state. A nearly flat virial parameter–mass ( α vir − M ) distribution is seen across all density scales, with α vir values centered around unity, suggesting a global equilibrium maintained by the interplay between gravity and turbulence across multiple scales. Our turbulent energy spectrum ( E ( k )) analysis, based on the σ – L and ρ – L scalings, yields a characteristic E ( k ) ∝ k −1.52 . These findings indicate the potential significance of gravity, turbulence, and possibly magnetic fields in regulating dynamics of molecular clouds and high-mass star formation therein.