The Role of Dust in the Transfer of Ionizing Radiation

Dust has been recognized as a crucial component of galaxies that strongly influences Interstellar Medium (ISM) chemistry and physics, such as the transport of electromagnetic radiation. In particular sources of hydrogen ionizing radiation (hν ≥ 13.6 eV) are frequently associated with dusty environments, resulting in a complicated interplay of radiation, gas and dust. By extension dust also shapes the spectra of radiation that escapes galaxies and thus might have played an indirect role in cosmic reionization. To quantitatively study these processes we extend the radiative transfer code CRASH by a dust module. While at the moment only the absorption of radiation is modelled, we are working on refining the treatment of the complex physics of solid grains to include effects such as grain charging and heating. To test the current implementation we perform simulations in different astrophysical environments using a Milky Way dust model from the literature. We confirm that the results are in accordance with expectations from more qualitative considerations.