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arXiv · 1011.2064

The mass-loss rates and molecular abundances of S-type AGB stars

S. Ramstedt·F. L. Schöier·H. Olofsson
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Abstract

The S-type stars are believed to have a C/O-ratio close to unity (within a few percent). They are considered to represent an intermediate evolutionary stage as AGB stars evolve from oxygen-rich M-type stars into carbon stars. As possible transition objects the S-type stars could give important clues to the mass-loss mechanism(s) and to the chemical evolution along the AGB. Using observations of circumstellar radio line emission in combination with a detailed radiative transfer analysis, we have estimated mass-loss rates and abundances of chemically important molecules (SiO, HCN) for a sample of 40 S-type AGB stars. The results will be compared to previous results for M-type and carbon stars.

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S. Ramstedt, F. L. Schöier, H. Olofsson. 2010-11-09. The mass-loss rates and molecular abundances of S-type AGB stars. https://arxiv.org/abs/1011.2064

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