Mass-loss properties of S-stars on the AGB
Abstract
We have used a detailed non-LTE radiative transfer code to model new APEX CO(J=3-2) data, and existing CO radio line data, on a sample of 40 AGB S-stars. The derived mass-loss-rate distribution has a median value of 2E-7 Msun/yr, and resembles values obtained for similar samples of M-stars and carbon stars. Possibly, there is a scarcity of high-mass-loss-rate (>=1E-5 Msun/yr) S-stars. The distribution of envelope gas expansion velocities is similar to that of the M-stars, the median is 7.5 km/s, while the carbon stars, in general, have higher gas expansion velocities. The mass-loss rate correlates well with the gas expansion velocity, in accordance with results for M-stars and carbon stars.
Cite
@article{arxiv.astro-ph/0605664,
title = {Mass-loss properties of S-stars on the AGB},
author = {S. Ramstedt and F. L. Schoeier and H. Olofsson and A. A. Lundgren},
journal= {arXiv preprint arXiv:astro-ph/0605664},
year = {2009}
}
Comments
Accepted for publication in the A&A APEX special issue. 5 pages, 2 figures