The influence of chemical ionization and chemical recombination processes on the plasma parameters in low-temperature layers of stellar atmospheres

摘要

In this paper we have presented some of our preliminary results illustrating the influence of a group of symmetrical chemical ionization and chemical recombination processes on the populations of hydrogen-atom Rydberg states in low-temperature layers of stellar photospheres and a part of chromospheres. These processes are H~*(n) + H(1s) → H_2~+ + e/H(1s) + H~+ + e and H_2~+ + e → H~*(n) + H(1s), H(1s) + H~+ + e → H~*(n) + H(1s), where H~*(n) is the hydrogen atom in a Rydberg state with the principal quantum number n 1, and H_2~+ is the hydrogen molecular ion in a weakly bound rovibrational state. The mentioned processes have been considered within the framework of the semiclassical approximation, developed in several previous papers. Their influence on the populations of hydrogen-atom Rydberg states has been investigated by direct inclusion in a computer code for stellar atmosphere modelling. Here we present some of our preliminary results for the M dwarf atmospheres. Our results show that the influence of these processing is significant for the considered stellar atmospheres, so that they should be taken into account for their modelling.