1302.6188 (V. A. Sreckovic et al.)

Excitation and deexcitation processes in atom-Rydberg atom collisions in helium-rich white dwarf atmospheres    [PDF]

V. A. Sreckovic, A. A. Mihajlov, Lj. M. Ignjatovic, M. S. Dimitrijevic

We aim to show the importance of non-elastic excitation and deexcitation processes in $\textrm{He}^{*}(n)+ \textrm{He}(1s^{2})$ collisions with the principal quantum number $n \ge 3$ for helium-rich white dwarf atmospheres. We compare the efficiencies of these processes with those of the known non-elastic electron-$\textrm{He}^{*}(n)$ atom processes in the atmospheres of some DB white dwarfs. We show that in significant parts of the considered atmospheres, which contain weakly ionized layers (the ionization degree $\lesssim 10^{-3}$), the influence of the studied atom-Rydberg atom processes on excited helium atom populations is dominant or at least comparable to the influence of the concurrent electron-$\textrm{He}^{*}(n)$-atom processes.

View original: http://arxiv.org/abs/1302.6188