Manifestation of the light-induced drift effect in chemically peculiar stellar atmospheres

Abstract

We have calculated the factor (νg − νe)/νg in the temperature range T = 300–20 000 K for the ions Be+, Mg+, Ca+, C+ in atomic hydrogen and for the ions Mg+ in atomic argon using the known interaction potentials. Here νe and νg are the transport collision frequencies for excited- and ground-state particles respectively. Calculations have shown that at T = 10 000–20 000 K, typical temperatures of the atmospheres of chemically peculiar (CP) stars, the values |νg − νe|/νg ≈ 0.1–0.2 can be reached for ions. This causes the light-induced drift (LID) velocity of ions up to ∼0.1 cm/s in the atmospheres of CP stars with temperatures T T > 10 000 K) it is possible to expect approximately identical magnitude of the LID effect and that of radiation pressure. In the very hot stars (T >20 000 K) the LID effect is manifested very weakly.