Lyman Radiation Hydrodynamics of Turbulent H II Regions in Molecular Clouds: A Physical Origin of LyC Leakage and the Associated Ly$\alpha$ Spectra

Understand

We examine Lyman continuum (LyC) leakage through H II regions regulated by turbulence and radiative feedback in a giant molecular cloud in the context of fully-coupled radiation hydrodynamics (RHD).

• The physical relations of the LyC escape with H I covering fraction, kinematics, spectral hardness, and the emergent Lyman-$\alpha$ (Ly$\alpha$) line profiles are studied using a series of RHD turbulence simulations performed with RAMSES-RT.
• The turbulence-regulated mechanism allows ionizing photons to leak out at early times before the onset of supernova feedback.
• The LyC photons escape through turbulence-generated low column density channels which are evacuated efficiently by radiative feedback via photoheating-induced shocks across the D-type ionization fronts.