J/A+A/668/A100ivo://CDS.VizieR/J/A+A/668/A100doi:10.26093/cds/vizier.36680100CDSGil-Pons P.Doherty C.L.Campbell S.W.Gutierrez J.2024-11-28T20:01:13Z2022-12-08T12:19:11ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frstellar-evolutionary-modelscarbon-starschemically-peculiar-starspopulation-ii-starschemical-abundancesStellar models and nucleosynthetic yields of primordial to extremely metal-poor (EMP) stars are crucial to interpret the surface abundances of the most metal-poor stars observed, and ultimately, to better understand the earliest stellar populations. In addition, they are key ingredients of Galactic chemical evolution models. We aim to better characterize the evolution and fates, and determine updated nucleosynthetic yields of intermediate-mass stars between primordial and EMP metallicity (Z=10^-10^, 10^-8^, 10^-7^, 10^-6^, and 10^-5^). We also probe uncertainties in the nucleosynthesis of the oldest intermediate-mass stars, namely those related to the treatment of convection and convective boundaries, and those related to wind prescriptions during the Asymptotic Giant Branch (AGB) phase. We analyse the evolution of models from their main sequence, through the thermally-pulsing AGB (TP-AGB), till the latest stages of their evolution, using the Monash-Mount Stromlo stellar evolution code MONSTAR. Results are post-processed with the code MONSOON, which allows the determination of the nucleosynthetic yields of 77 species up to ^62^Ni. By comparing to similar calculations existing in the literature, we inspect the effects of input physics on the nucleosynthesis of EMP models. From the evolutionary point of view, as reported in former works, we identify proton ingestion episodes (PIE) in our lowest-mass lowest- metallicity models. Models of Z=10^-10^ and Z=10^-8^ in a narrow initial mass range around 5M_{sun}_ experience the cessation of thermal pulses, and their final fates as supernovae I1/2 (SNeI1/2) cannot be discarded, however, the initial mass range of models eventually leading to the formation of SNe I1/2 and electron-capture SNe is considerably reduced compared to former works. All the models of initial mass >~6-7M_{sun}_ experience a corrosive second dredge-up and, analogously to those experiencing PIEs, undergo significant metal enrichment in their envelopes. The associated increase in their opacities allows them to develop a solar-like TP-AGB or TP-super-AGB, TP-(S)AGB phase and ultimately become white dwarfs. Except those undergoing the cessation of thermal pulses, all our models show the nucleosynthetic signatures of both efficient third dredge-up and hot-bottom burning, with the activation of the NeNa-cycle and the MgAlSi-chains. This leads to the creation of vast amounts of CNO, with typical [N/Fe]~>~4), and the characteristic abundance signature [N/Fe]~>~[C/Fe]~>~[O/Fe]. Our nucleosynthetic yields present dramatic differences with respect to recent results existing in the literature for intermediate-mass models of similar metallicities. The reason for these discrepancies lay in the poorly known input physics related to stellar winds and, above all, the treatment of convection and convective boundaries.2022A&A...668A.100Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/668/A100CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/490/769 : Yields from extremely metal-poor stars (Campbell+, 2008)J/A+A/645/A10 : Yields for Z=1e-5 intermediate-mass stars (Gil-Pons+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/668/A100https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/668/A100http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/668/A100https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/668/A100https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/668/A100http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/668/A100GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/668/A100/z1em06Yields computed for models of Z=1e-6ZMetallicityphys.abund.ZdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMiniInitial masssolMassphys.massfloatSpeciesSpecies imeta.notecharA(i)Atomic mass of iphys.atmol.weightintYield(i)Yield of isolMassphys.composition.yielddoubleMeject(i)Ejected mass of isolMassphys.composition.yielddoubleMini(i)Initial mass of i, M0(i)solMassphys.composition.yielddouble<X(i)>Average abundance of i in the windphys.abunddoubleX0(i)Initial abundance of iphys.abunddoublelog(<X(i)>/X0(i))log10 of production factor of iphys.abunddoubleJ/A+A/668/A100/z1em07Yields computed for models of Z=1e-7recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintZMetallicityphys.abund.ZdoubleMiniInitial masssolMassphys.massfloatSpeciesSpecies imeta.notecharA(i)Atomic mass of iphys.atmol.weightintYield(i)Yield of isolMassphys.composition.yielddoubleMeject(i)Ejected mass of isolMassphys.composition.yielddoubleMini(i)Initial mass of i, M0(i)solMassphys.composition.yielddouble<X(i)>Average abundance of i in the windphys.abunddoubleX0(i)Initial abundance of iphys.abunddoublelog(<X(i)>/X0(i))log10 of production factor of iphys.abunddoubleJ/A+A/668/A100/z1em08Yields computed for models of Z=1e-8recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintZMetallicityphys.abund.ZdoubleMiniInitial masssolMassphys.massfloatSpeciesSpecies imeta.notecharA(i)Atomic mass of iphys.atmol.weightintYield(i)Yield of isolMassphys.composition.yielddoubleMeject(i)Ejected mass of isolMassphys.composition.yielddoubleMini(i)Initial mass of i, M0(i)solMassphys.composition.yielddouble<X(i)>Average abundance of i in the windphys.abunddoubleX0(i)Initial abundance of iphys.abunddoublelog(<X(i)>/X0(i))log10 of production factor of iphys.abunddoubleJ/A+A/668/A100/z1em10Yields computed for models of Z=1e-10recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintZMetallicityphys.abund.ZdoubleMiniInitial masssolMassphys.massfloatSpeciesSpecies imeta.notecharA(i)Atomic mass of iphys.atmol.weightintYield(i)Yield of isolMassphys.composition.yielddoubleMeject(i)Ejected mass of isolMassphys.composition.yielddoubleMini(i)Initial mass of i, M0(i)solMassphys.composition.yielddouble<X(i)>Average abundance of i in the windphys.abunddoubleX0(i)Initial abundance of iphys.abunddoublelog(<X(i)>/X0(i))log10 of production factor of iphys.abunddouble