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Paper: |
Circumstellar Envelopes as AGB Mass-Loss Signatures |
Volume: |
378, Why Galaxies Care About AGB Stars: Their Importance as Actors and Probes |
Page: |
345 |
Authors: |
Villaver, E.; Garcia-Segura, G.; Manchado, A. |
Abstract: |
Low- and intermediate-mass stars (1–8 M⊙) lose up to 80% of their initial mass during the Asymptotic Giant Branch (AGB) phase. Heavy mass loss is the signature of the late AGB phase: at uncertain rates of 10−6 to 10−3M⊙ yr−1, on timescales of ~105–106 yr, it removes up to 7 M⊙ of stellar material. We have investigated the dynamical interaction of these winds with their interstellar medium (ISM) by using a numerical code and the wind history predicted by stellar evolution. Our aim is to allow a comparison between the AGB mass-loss rate predictions and observations of planetary nebula and AGB shells. According to our simulations, large regions (up to 2.5 pc) of neutral gas surrounding the molecular envelopes of AGB stars are expected. These large regions of gas are formed from the mass loss experienced by the star during AGB evolution and are strongly linked to the assumed timescales of heavy mass-loss rates. |
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