SIMBAD references

2021ApJ...908...30K - Astrophys. J., 908, 30-30 (2021/February-2)

Radiation hydrodynamics of turbulent H II regions in molecular clouds: a physical origin of LyC leakage and the associated Lyα spectra.

KAKIICHI K. and GRONKE M.

Abstract (from CDS):

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, ionizing photon production efficiency, and emergent Lyα 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 that are evacuated efficiently by radiative feedback via photoheating-induced shocks across the D-type ionization fronts. The Lyα photons funnel through the photoionized channels along the paths of LyC escape, resulting in a diverse Lyα spectral morphology including narrow double-peaked profiles. The Lyα peak separation is controlled by the residual H I column density of the channels, and the line asymmetry correlates with the porosity and multiphase structure of the H II region. This mechanism through the turbulent H II regions can naturally reproduce the observed Lyα spectral characteristics of some of the LyC-leaking galaxies. This RHD turbulence origin provides an appealing hypothesis to explain high LyC leakage from very young (∼3 Myr) star-forming galaxies found in the local universe without need of extreme galactic outflows or supernova feedback. We discuss the implications of the turbulent H II regions on other nebular emission lines and a possible observational test with the Magellanic System and local blue compact dwarf galaxies as analogs of reionization-era systems.

Abstract Copyright: © 2021. The American Astronomical Society. All rights reserved.

Journal keyword(s): Reionization - H II regions - Hydrodynamics - Radiative transfer

Simbad objects: 24

goto Full paper

goto View the references in ADS

To bookmark this query, right click on this link: simbad:2021ApJ...908...30K and select 'bookmark this link' or equivalent in the popup menu