The Influence of Chemi-ionization and Recombination Processes on Spectral Line Shapes in Stellar Atmospheres

TL;DR

This paper investigates how chemi-ionization and recombination processes in atom-Rydberg atom collisions significantly influence spectral line shapes and optical properties in stellar atmospheres, especially in non-LTE conditions.

Contribution

It demonstrates that chemi-ionization and recombination processes dominate over other ionization/recombination mechanisms in stellar atmospheres, highlighting their importance in spectral modeling.

Findings

Chemi-ionization/recombination processes dominate in stellar atmospheres.

These processes significantly affect optical properties.

Further investigation needed for non-LTE modeling.

Abstract

In this work, the chemi-ionization processes in atom- Rydberg atom collisions, as well as the corresponding chemi-recombination processes are considered as factors of influence on the atom exited-state populations in weakly ionized layers of stellar atmospheres. The presented results are related to the photospheres of the Sun and some M red dwarfs as well as weakly ionized layers of DB white dwarfs atmospheres. It has been found that the mentioned chemi ionization/recombination processes dominate over the relevant concurrent electron-atom and electron-ion ionization and recombination process in all parts of considered stellar atmospheres. The obtained results demonstrate the fact that the considered chemi ionization/recombination processes must have a very significant influence on the optical properties of the stellar atmospheres. Thus, it is shown that these processes and their importance for non-local thermodynamic equilibrium (non-LTE) modeling of the solar atmospheres should be investigated further.