Fingering convection in red giants revisited

Context. Fingering (thermohaline) convection has been invoked for several years as a possible extra-mixing which could occur in red giant stars; it is due to the modification of the chemical composition induced by nuclear reactions in the hydrogen burning zone. Recent studies show, however, that thi...

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Detalles Bibliográficos
Autores principales: Wachlin, Felipe Carlos, Vauclair, S., Althaus, Leandro Gabriel
Formato: Articulo
Lenguaje:Inglés
Publicado: 2014
Materias:
Ciencias Astronómicas
Instabilities
Stars: abundances
Stars: evolution
Stars: interiors
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/84833
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-84833
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
Instabilities
Stars: abundances
Stars: evolution
Stars: interiors
spellingShingle Ciencias Astronómicas
Instabilities
Stars: abundances
Stars: evolution
Stars: interiors
Wachlin, Felipe Carlos
Vauclair, S.
Althaus, Leandro Gabriel
Fingering convection in red giants revisited
topic_facet Ciencias Astronómicas
Instabilities
Stars: abundances
Stars: evolution
Stars: interiors
description Context. Fingering (thermohaline) convection has been invoked for several years as a possible extra-mixing which could occur in red giant stars; it is due to the modification of the chemical composition induced by nuclear reactions in the hydrogen burning zone. Recent studies show, however, that this mixing is not sufficient to account for the needed surface abundances. Aims. A new prescription for fingering convection, based on 3D numerical simulations has recently been proposed. The resulting mixing coefficient is larger than those previously given in the literature. We compute models using this new coefficient and compare them to previous studies. Methods. We used the LPCODE stellar evolution code with a generalized version of the mixing length theory to compute red giant models and we introduce fingering convection using the BGS prescription. Results. The results show that, although the fingering zone now reaches the outer dynamical convective zone, the efficiency of the mixing is not enough to account for the observations. The fingering mixing coefficient should be increased by two orders of magnitude for the needed surface abundances to be reached. Conclusions. We confirm that fingering convection cannot be the mixing process needed to account for surface abundances in red giant branch stars.
format Articulo
Articulo
author Wachlin, Felipe Carlos
Vauclair, S.
Althaus, Leandro Gabriel
author_facet Wachlin, Felipe Carlos
Vauclair, S.
Althaus, Leandro Gabriel
author_sort Wachlin, Felipe Carlos
title Fingering convection in red giants revisited
title_short Fingering convection in red giants revisited
title_full Fingering convection in red giants revisited
title_fullStr Fingering convection in red giants revisited
title_full_unstemmed Fingering convection in red giants revisited
title_sort fingering convection in red giants revisited
publishDate 2014
url http://sedici.unlp.edu.ar/handle/10915/84833
work_keys_str_mv AT wachlinfelipecarlos fingeringconvectioninredgiantsrevisited
AT vauclairs fingeringconvectioninredgiantsrevisited
AT althausleandrogabriel fingeringconvectioninredgiantsrevisited
bdutipo_str Repositorios
_version_ 1764820488631091201

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