New evolutionary models for massive ZZ Ceti stars : I. First results for their pulsational properties

We present new and improved evolutionary calculations for carbon-oxygen white dwarf (WD) stars appropriate for the study of massive ZZ Ceti stars. To this end, we follow the complete evolution of massive WD progenitors from the zero-age main sequence through the thermally pulsing and mass loss phase...

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Detalles Bibliográficos
Autores principales: Althaus, Leandro Gabriel, Serenelli, Aldo Marcelo, Córsico, Alejandro Hugo, Montgomery, M. H.
Formato: Articulo
Lenguaje:Inglés
Publicado: 2003
Materias:
Ciencias Astronómicas
Stars: abundances
Stars: AGB
Stars: evolution
Stars: interiors
Stars: oscillations
Stars: white dwarfs
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/84614
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-84614
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
Stars: abundances
Stars: AGB
Stars: evolution
Stars: interiors
Stars: oscillations
Stars: white dwarfs
spellingShingle Ciencias Astronómicas
Stars: abundances
Stars: AGB
Stars: evolution
Stars: interiors
Stars: oscillations
Stars: white dwarfs
Althaus, Leandro Gabriel
Serenelli, Aldo Marcelo
Córsico, Alejandro Hugo
Montgomery, M. H.
New evolutionary models for massive ZZ Ceti stars : I. First results for their pulsational properties
topic_facet Ciencias Astronómicas
Stars: abundances
Stars: AGB
Stars: evolution
Stars: interiors
Stars: oscillations
Stars: white dwarfs
description We present new and improved evolutionary calculations for carbon-oxygen white dwarf (WD) stars appropriate for the study of massive ZZ Ceti stars. To this end, we follow the complete evolution of massive WD progenitors from the zero-age main sequence through the thermally pulsing and mass loss phases to the WD regime. Abundance changes are accounted for by means of a full coupling between nuclear evolution and time-dependent mixing due to diffusive overshoot, semiconvection and salt fingers. In addition, time-dependent element diffusion for multicomponent gases has been considered during the WD stage. Emphasis is placed on the chemistry variations along the whole evolution. In particular, we find that before the ZZ Ceti stage is reached, element diffusion has strongly smoothed out the chemical profile to such a degree that the resulting internal abundance distribution does not depend on the occurrence of overshoot episodes during the thermally pulsing phase. The mass of the hydrogen envelope left at the ZZ Ceti domain amounts to M<SUB>H</SUB> ≈ 2.3 × 10<SUP>-6</SUP> M⊙. This is about half as large as for the case when element diffusion is neglected. The implications of our new models for the pulsational properties of massive ZZ Ceti stars are discussed. In this regard, we find that the occurrence of core overshooting during central helium burning leaves strong imprints on the theoretical period spectrum of massive ZZ Ceti stars. Finally, we present a simple new prescription for calculating the He/H profile which goes beyond the trace element approximation.
format Articulo
Articulo
author Althaus, Leandro Gabriel
Serenelli, Aldo Marcelo
Córsico, Alejandro Hugo
Montgomery, M. H.
author_facet Althaus, Leandro Gabriel
Serenelli, Aldo Marcelo
Córsico, Alejandro Hugo
Montgomery, M. H.
author_sort Althaus, Leandro Gabriel
title New evolutionary models for massive ZZ Ceti stars : I. First results for their pulsational properties
title_short New evolutionary models for massive ZZ Ceti stars : I. First results for their pulsational properties
title_full New evolutionary models for massive ZZ Ceti stars : I. First results for their pulsational properties
title_fullStr New evolutionary models for massive ZZ Ceti stars : I. First results for their pulsational properties
title_full_unstemmed New evolutionary models for massive ZZ Ceti stars : I. First results for their pulsational properties
title_sort new evolutionary models for massive zz ceti stars : i. first results for their pulsational properties
publishDate 2003
url http://sedici.unlp.edu.ar/handle/10915/84614
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AT serenellialdomarcelo newevolutionarymodelsformassivezzcetistarsifirstresultsfortheirpulsationalproperties
AT corsicoalejandrohugo newevolutionarymodelsformassivezzcetistarsifirstresultsfortheirpulsationalproperties
AT montgomerymh newevolutionarymodelsformassivezzcetistarsifirstresultsfortheirpulsationalproperties
bdutipo_str Repositorios
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