Title:
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The evolution and C, N and O yields of intermediate-mass Z = 10-5 stars in isolation and in close binary systems
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Author:
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Gil Pons, Pilar; Doherty, Carolyn L.; Suda, T.; Campbell, Simon; Lau, H.; Mansouri Guilani, Shervin; Lattanzio, John
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Other authors:
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Universitat Politècnica de Catalunya. Departament de Física Aplicada; Universitat Politècnica de Catalunya. DF - Dinàmica No Lineal de Fluids |
Abstract:
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We have computed the evolution of Z = 10−5 stars of masses between 4 and 9 M , from their
main sequence till the late TP-(S)AGB phase.We use a recent version of the Mount Stromlo Stellar
Evolution code, in which molecular opacities include the effects of variable C/O abundances ratio,
[1]. By computing hundreds (or thousands) of thermal pulses, we have been able either to remove
the bulk of the stellar envelopes or to obtain stellar cores very close to MCh. Using [2] prescription
for the mass loss rates the computed stars lose their envelopes before their cores reach MCh. This
would forbid the occurrence of SN 1.5 for Z = 10−5 stars. Nevertheless the results by [3] suggest
that the former prescription might overestimate the mass-loss rates. Therefore we have decreased
the rates by [2]. For all the cases we present, even a decrease of one order of magnitude let the
stellar cores reach MCh before the envelope is lost. Therefore the occurrence of SN1.5 at Z = 10 −5
and their potential contribution to the chemical evolution of the Universe should not be discarded.
We consider the combined effects of the deep/corrosive 2 nd dredge-up and Roche Lobe Overflow
(RLOF) during the E-AGB to help to constrain the contribution of massive Z = 10 −5 AGB stars to
the CEMPs problem. Our results have implications for the chemical evolution of the Universe and
might provide another piece for the puzzle of the CEMPs problem. |
Abstract:
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Peer Reviewed |
Subject(s):
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-Àrees temàtiques de la UPC::Física::Astronomia i astrofísica -First stars -Stars--Evolution -Asymptotic giant branch stars -Estels -- Evolució |
Rights:
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Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/ |
Document type:
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Article - Published version Conference Object |
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