Radiative transfer of ionizing radiation through gas and dust: stellar source case

TL;DR

This paper introduces a new dust extension to the Monte Carlo radiative transfer code crash, enabling simulation of ionizing radiation through gas and dust mixtures, and studies dust's impact on H II regions and reionization.

Contribution

The paper presents a novel dust extension to the crash code, allowing detailed modeling of dust effects on ionizing radiation propagation in astrophysical environments.

Findings

Dust reduces the size of H II regions without affecting their temperature and ionization structure.

Dust presence delays reionization bubble overlap by hardening ionization fronts.

The effect of dust on reionization is weakly dependent on dust abundance in underdense regions.

Abstract

We present a new dust extension to the Monte Carlo radiative transfer code crash, which enables it to simulate the propagation of ionizing radiation through mixtures of gas and dust. The new code is applied to study the impact of dust absorption on idealized galactic H II regions and on small scale reionization. We find that H II regions are reduced in size by the presence of dust, while their inner temperature and ionization structure remain largely unaffected. In the small scale reionization simulation, dust hardens ionization fronts and delays the overlap of ionized bubbles. This effect is found to depend only weakly on the assumed abundance of dust in underdense regions.