Winds from low mass stars: Impact on the ISM
Por:
Villaver E., García-Segura G., Manchado A.
Publicada:
1 ene 2004
Resumen:
A large fraction of all stars, after experiencing heavy winds at the end of the Asymptotic Giant Branch (AGB) phase, leave behind a core that is below the Chandrasekhar mass limit. This core eventually photoionizes the stellar ejecta giving birth to a planetary nebula (PN). PN and AGB stars are therefore the remnants of stars that through their winds contribute to the chemical enrichment of the ISM with elements He, C, N and O. We have explored the impact of such winds in the ISM and in the formation and evolution of the circumstellar envelopes around AGB stars and PN shells. In our simulations, we find that huge shells (up to 2.5 pc in radius) are formed as a consequence of the mass-loss during the early AGB phase. When the star is at rest with respect to the ISM, these shells contain a large fraction of ISM material that has been swept up by the stellar wind. We find that when the star is moving and the ram pressure is high enough, significant dispersal between the stellar ejecta and the ISM material still takes place due to instabilities, however, the mass and the size of the envelope are highly reduced due to ram pressure stripping.
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