Kaiser, EA, Hirschi, R, Arnett, WD, Georgy, C, Scott, LJA and Cristini, A (2020) Relative Importance of Convective Uncertainties in Massive Stars. Monthly Notices of the Royal Astronomical Society, 496 (2). pp. 1967-1989. ISSN 0035-8711

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In this work, we investigate the impact of uncertainties due to convective boundary mixing (CBM), commonly called ‘overshoot’, namely the boundary location and the amount of mixing at the convective boundary, on stellar structure and evolution. For this we calculated two grids of stellar evolution models with the MESA code, each with the Ledoux and the Schwarzschild boundary criterion, and vary the amount of CBM. We calculate each grid with the initial masses 15, 20 and $25\, \rm M_ødot$. We present the stellar structure of the models during the hydrogen and helium burning phases. In the latter, we examine the impact on the nucleosynthesis. We find a broadening of the main-sequence with more CBM, which is more in agreement with observations. Furthermore during the core hydrogen burning phase there is a convergence of the convective boundary location due to CBM. The uncertainties of the intermediate convective zone remove this convergence. The behaviour of this convective zone strongly affects the surface evolution of the model, i.e. how fast it evolves red-wards. The amount of CBM impacts the size of the convective cores and the nucleosynthesis, e.g. the 12C to 16O ratio and the weak s-process. Lastly, we determine the uncertainty that the range of parameter values investigated introduce and we find differences of up to $70%$ for the core masses and the total mass of the star.

Item Type: Article
Additional Information: This article has been accepted for publication in [Monthly Notices of the Royal Astronomical Society] ©: [2020] [R. Hirschi] Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. The final version of this article and all relevant information needed can be found at; https://academic.oup.com/mnras/article-abstract/496/2/1967/5854575?redirectedFrom=fulltext
Uncontrolled Keywords: convection, stars: evolution, stars: interiors, stars: massive, nucleosynthesis
Subjects: Q Science > Q Science (General)
Q Science > QB Astronomy
Q Science > QB Astronomy > QB460 Astrophysics
Q Science > QB Astronomy > QB799 Stars
Q Science > QC Physics
Divisions: Faculty of Natural Sciences > School of Chemical and Physical Sciences
Related URLs:
Depositing User: Symplectic
Date Deposited: 17 Jul 2020 11:22
Last Modified: 03 Sep 2020 07:55
URI: https://eprints.keele.ac.uk/id/eprint/8368

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