Fast methods to track grain coagulation and ionization. II. Extension to thermal ionization

TL;DR

This paper extends a fast computational method to include thermal ionization effects, enabling efficient calculation of ionization states in star-forming environments, which is crucial for modeling magnetic resistivities during protostar formation.

Contribution

An extension of a previous fast ionization method to incorporate thermal ionization, facilitating efficient and self-consistent calculations in astrophysical simulations.

Findings

Enables rapid computation of ion and electron densities.

Allows modeling of grain charge distribution across sizes.

Supports multidimensional simulations of star formation processes.

Abstract

Thermal ionization is a critical process at temperatures T > 10 3 K, particularly during star formation. An increase in ionization leads to a decrease in nonideal magnetohydrodynamics (MHD) resistivities, which has a significant impact on protoplanetary disks and protostar formation. We developed an extension of the fast computational ionization method presented in our recent paper to include thermal ionization. The model can be used to inexpensively calculate the density of ions and electrons and the electric charge of each size of grains for an arbitrary size distribution. This tool should be particularly useful for the self-consistent calculation of nonideal MHD resistivities in multidimensional simulations, especially of protostellar collapse and protoplanetary disks.