Annotation
It is shown that the gas surrounding a hot star is excited mainly by the stellar radiation field. The contribution of the excited states to the ionization rate $R_{\rm exc}$ can noticeably exceed that of the basic state $R_{\rm base}$. A simple approximation formula is obtained for the ratio $R_{\rm exc}/R_{\rm base}$.
Received: 2010 October 31
Approved: 2011 September 21
PACS:
97.90.+j Other topics on stars
© 2016 Publisher M.V.Lomonosov Moscow State University
Authors
K.V. Bychkov, E.S. Morchenko
State Institute of Astronomy, Universitetskii pr. 13, Moscow, 119191, Russia
State Institute of Astronomy, Universitetskii pr. 13, Moscow, 119191, Russia
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