Atom-Rydberg atom processes in the stellar atmospheres: DB white-dwarf atmospheres and solar atmosphere

International audienceNowadays elementary processes in astrophysical phenomena still attract researchers' attention. This can be attributed to a group of chemi-ionization processes and exitation/deexcitation processes in Rydberg atom collisions with ground state parent atoms. The rate coefficients of the chemi-ionization processes in H(1s) H*(n,l) and He(1s2) He*(n,l) collisions, taking into account the influence of the corresponding (n-n')-mixing processes, are determined for the temperature range characteristic of the solar and DB white-dwarf atmospheres. The theory and modeling is done on the basis of the method described in Mihajlov et al. (2015, 2016). The direct calculations of the chemi-ionization rate coefficients are carried out for the models of the quiet Sun and DB white-dwarf atmospheres. It is demonstrated that the inclusion of (n-n')-mixing uences the values of chemi-ionization rate coefficients significantly in all examined cases of stellar atmospheres