New nonadiabatic pulsation computations on full PG 1159 evolutionary models: The theoretical GW Virginis instability strip revisited

Aims. We reexamine the theoretical instability domain of pulsating PG 1159 stars (GW Vir variables). Methods. We performed an extensive g-mode stability analysis on PG 1159 evolutionary models with stellar masses ranging from 0.530 to 0.741 M⊙, for which the complete evolutionary stages of their p...

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Autores principales: Córsico, Alejandro Hugo, Althaus, Leandro Gabriel, Miller Bertolami, Marcelo Miguel
Formato: Articulo
Lenguaje:Inglés
Publicado: 2006
Materias:
Ciencias Astronómicas
Stars: evolution
Stars: interiors
Stars: oscillations
White dwarfs
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83211
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-83211
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: evolution
Stars: interiors
Stars: oscillations
White dwarfs
spellingShingle Ciencias Astronómicas
Stars: evolution
Stars: interiors
Stars: oscillations
White dwarfs
Córsico, Alejandro Hugo
Althaus, Leandro Gabriel
Miller Bertolami, Marcelo Miguel
New nonadiabatic pulsation computations on full PG 1159 evolutionary models: The theoretical GW Virginis instability strip revisited
topic_facet Ciencias Astronómicas
Stars: evolution
Stars: interiors
Stars: oscillations
White dwarfs
description Aims. We reexamine the theoretical instability domain of pulsating PG 1159 stars (GW Vir variables). Methods. We performed an extensive g-mode stability analysis on PG 1159 evolutionary models with stellar masses ranging from 0.530 to 0.741 M⊙, for which the complete evolutionary stages of their progenitors from the ZAMS, through the thermally pulsing AGB and born-again phases to the domain of the PG 1159 stars have been considered. Results. We found that pulsations in PG 1159 stars are excited by the k-mechanism due to partial ionization of carbon and oxygen, and that no composition gradients are needed between the surface layers and the driving region, much in agreement with previous studies. We show, for the first time, the existence of a red edge of the instability strip at high luminosities. We found that all of the GW Vir stars lay within our theoretical instability strip. Our results suggest a qualitative good agreement between the observed and the predicted ranges of unstable periods of individual stars. Finally, we found that generally the seismic masses (derived from the period spacing) of GW Vir stars are somewhat different from the masses suggested by evolutionary tracks coupled with spectroscopy. Improvements in the evolution during the thermally pulsing AGB phase and/or during the core helium burning stage and early AGB could help to alleviate the persisting discrepancies.
format Articulo
Articulo
author Córsico, Alejandro Hugo
Althaus, Leandro Gabriel
Miller Bertolami, Marcelo Miguel
author_facet Córsico, Alejandro Hugo
Althaus, Leandro Gabriel
Miller Bertolami, Marcelo Miguel
author_sort Córsico, Alejandro Hugo
title New nonadiabatic pulsation computations on full PG 1159 evolutionary models: The theoretical GW Virginis instability strip revisited
title_short New nonadiabatic pulsation computations on full PG 1159 evolutionary models: The theoretical GW Virginis instability strip revisited
title_full New nonadiabatic pulsation computations on full PG 1159 evolutionary models: The theoretical GW Virginis instability strip revisited
title_fullStr New nonadiabatic pulsation computations on full PG 1159 evolutionary models: The theoretical GW Virginis instability strip revisited
title_full_unstemmed New nonadiabatic pulsation computations on full PG 1159 evolutionary models: The theoretical GW Virginis instability strip revisited
title_sort new nonadiabatic pulsation computations on full pg 1159 evolutionary models: the theoretical gw virginis instability strip revisited
publishDate 2006
url http://sedici.unlp.edu.ar/handle/10915/83211
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AT althausleandrogabriel newnonadiabaticpulsationcomputationsonfullpg1159evolutionarymodelsthetheoreticalgwvirginisinstabilitystriprevisited
AT millerbertolamimarcelomiguel newnonadiabaticpulsationcomputationsonfullpg1159evolutionarymodelsthetheoreticalgwvirginisinstabilitystriprevisited
bdutipo_str Repositorios
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