Bibcode
Ventura, P.; Karakas, A.; Dell'Agli, F.; García-Hernández, D. A.; Guzman-Ramirez, L.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 475, Issue 2, p.2282-2305
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4
2018
Citations
65
Refereed citations
63
Description
We study the asymptotic giant branch (AGB) evolution of stars with
masses between 1 M⊙and8.5 M⊙. We focus on
stars with a solar chemical composition, which allows us to interpret
evolved stars in the Galaxy. We present a detailed comparison with
models of the same chemistry, calculated with a different evolution code
and based on a different set of physical assumptions. We find that stars
of mass ≥3.5 M⊙ experience hot bottom burning at the
base of the envelope. They have AGB lifetimes shorter than ˜3
× 105 yr and eject into their surroundings gas
contaminated by proton-capture nucleosynthesis, at an extent sensitive
to the treatment of convection. Low-mass stars with 1.5
M⊙ ≤ M ≤ 3 M⊙ become carbon stars.
During the final phases, the C/O ratio grows to ˜3. We find a
remarkable agreement between the two codes for the low-mass models and
conclude that predictions for the physical and chemical properties of
these stars, and the AGB lifetime, are not that sensitive to the
modelling of the AGB phase. The dust produced is also dependent on the
mass: low-mass stars produce mainly solid carbon and silicon carbide
dust, whereas higher mass stars produce silicates and alumina dust.
Possible future observations potentially able to add more robustness to
the present results are also discussed.
Related projects
Nucleosynthesis and molecular processes in the late stages of Stellar Evolution
Low- to intermediate-mass (M < 8 solar masses, Ms) stars represent the majority of stars in the Cosmos. They finish their lives on the Asymptotic Giant Branch (AGB) - just before they form planetary nebulae (PNe) - where they experience complex nucleosynthetic and molecular processes. AGB stars are important contributors to the enrichment of the
Domingo Aníbal
García Hernández