Pasetto, S;
Chiosi, C;
Chiosi, E;
Cropper, M;
Weiss, A;
(2016)
Theory of stellar convection - II. First stellar models.
Monthly Notices of the Royal Astronomical Society
, 459
(3)
pp. 3182-3202.
10.1093/mnras/stw858.
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Abstract
We present here the first stellar models on the Hertzsprung-Russell diagram, in which convection is treated according to the new scale-free convection theory (SFC theory) by Pasetto et al. The aim is to compare the results of the new theory with those from the classical, calibrated mixing-length (ML) theory to examine differences and similarities. We integrate the equations describing the structure of the atmosphere from the stellar surface down to a few per cent of the stellar mass using both ML theory and SFC theory. The key temperature over pressure gradients, the energy fluxes, and the extension of the convective zones are compared in both theories. The analysis is first made for the Sun and then extended to other stars of different mass and evolutionary stage. The results are adequate: The SFC theory yields convective zones, temperature gradients ∇ and ∇e, and energy fluxes that are very similar to those derived from the 'calibrated' MT theory for main-sequence stars. We conclude that the old scale dependent ML theory can now be replaced with a self-consistent scale-free theory able to predict correct results, as it is more physically grounded than the ML theory. Fundamentally, the SFC theory offers a deeper insight of the underlying physics than numerical simulations.
Type: | Article |
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Title: | Theory of stellar convection - II. First stellar models |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1093/mnras/stw858 |
Publisher version: | https://doi.org/10.1093/mnras/stw858 |
Language: | English |
Additional information: | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
Keywords: | convection, Sun: evolution, Hertzsprung–Russell and colour, magnitude diagrams, stars: horizontal branch |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
URI: | https://discovery.ucl.ac.uk/id/eprint/1504552 |
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