Silicon and sulphur chemistry in the inner wind of IRC+10216 *
Karen Willacy and
Received 5 June 1997 / Accepted 22 August 1997
We present a dynamical and chemical model of the inner wind of the carbon-rich, AGB star IRC+10216. We include the effect of pulsation-driven shocks on the gas envelope close to the stellar photosphere and construct an extended chemical model that includes in particular the chemistry of hydrocarbon species and silicon and sulphur-bearing molecules. The derived theoretical abundances for many molecules are in excellent agreement with values obtained from observations of infrared ro-vibrational molecular lines. We confirm the "parent" character of certain chemical species and show that the inner wind of IRC+10216, and more generally of evolved AGB stars, is an active dynamical and chemical region where molecules are formed and processed.
Key words: molecular processes stars: AGB stars: individual: IRC+10216
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© European Southern Observatory (ESO) 1998
Online publication: January 16, 1998