What role of gravity, turbulence and magnetic fields in high-mass star formation clouds?

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 to 100 pc. We observe σ ∝ L0.26 and ρ ∝ L-1.54 scalings, converging toward a virial equilibrium state. A nearly flat virial parameter--mass (αᵥᵢᵣ-M) distribution is seen across all density scales, with αᵥᵢᵣ 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 all in regulating dynamics of molecular clouds and high-mass star formation therein.