Circumstellar molecular line emission from S-type AGB stars: Mass-loss rates and SiO abundances

  title={Circumstellar molecular line emission from S-type AGB stars: Mass-loss rates and SiO abundances},
  author={Sofia Ramstedt and Fredrik L. Schoeier and H. Olofsson},
  journal={Astronomy and Astrophysics},
Aims: The main aim is to derive reliable mass-loss rates and circumstellar SiO abundances for a sample of 40 S-type AGB stars based on new multi-transitional CO and SiO radio line observations. In addition, the results are compared to previous results for M-type AGB stars and carbon stars to look for trends with chemical type. Methods: The circumstellar envelopes are assumed to be spherically symmetric and formed by a constant mass-loss rate. The mass-loss rates are estimated from fitting the… 

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