Atom-Rydberg atom chemi-ionization/recombination processes in the hydrogen clouds in broad-line region of AGNs

Abstract

The possibility that the chemi-ionization processes in atom-Rydberg atom collisions, as well as the corresponding chemi-recombination processes, may be useful for the diagnostics, modelling, and confirmation of existence or non-existence of very dense weakly ionized domains in clouds in broad-line region of active galactic nuclei, has been considered. The obtained results demonstrate the fact that the considered chemi-ionization/recombination processes, which influence on the ionization level and atom excited-state populations, must have a very significant influence on the optical properties of the weakly ionized regions where the neutral hydrogen densities are larger than $10{12}, rm {cm}{-3}$ since in such conditions they dominate over the relevant concurrent electron-atom collision processes. This can be used as a diagnostic method to find out if the domains with such densities exist or not. Additionally, our previous results obtained for principal quantum number 2 ≤ n ≤ 8 and $4000 , textrm{K} le T le 10, 000 , textrm{K}$ are extended for principal quantum number 9 ≤ n ≤ 20 and $10, 000 , textrm{K} {lt} T le 20, 000 , textrm{K}$ and also for low-temperature region (T < 4000 K) for 2 ≤ n ≤ 20.