Quiescent nuclear burning in low-metallicity white dwarfs

We discuss the impact of residual nuclear burning in the cooling sequences of hydrogen-rich (DA) white dwarfs with very low metallicity progenitors (Z = 0.0001). These cooling sequences are appropriate for the study of very old stellar populations. The results presented here are the product of self-...

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Detalles Bibliográficos
Autores principales: Miller Bertolami, Marcelo Miguel, Althaus, Leandro Gabriel, García-Berro, E.
Formato: Articulo Preprint
Lenguaje:Inglés
Publicado: 2013
Materias:
Ciencias Astronómicas
stars: evolution
stars: interiors
white dwarfs
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/85519
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-85519
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
white dwarfs
spellingShingle Ciencias Astronómicas
stars: evolution
stars: interiors
white dwarfs
Miller Bertolami, Marcelo Miguel
Althaus, Leandro Gabriel
García-Berro, E.
Quiescent nuclear burning in low-metallicity white dwarfs
topic_facet Ciencias Astronómicas
stars: evolution
stars: interiors
white dwarfs
description We discuss the impact of residual nuclear burning in the cooling sequences of hydrogen-rich (DA) white dwarfs with very low metallicity progenitors (Z = 0.0001). These cooling sequences are appropriate for the study of very old stellar populations. The results presented here are the product of self-consistent, fully evolutionary calculations. Specifically, we follow the evolution of white dwarf progenitors from the zero-age main sequence through all the evolutionary phases, namely the core hydrogen-burning phase, the helium-burning phase, and the thermally pulsing asymptotic giant branch phase to the white dwarf stage. This is done for the most relevant range of main-sequence masses, covering the most usual interval of white dwarf masses - from 0.53 M⊙ to 0.83 M⊙. Due to the low metallicity of the progenitor stars, white dwarfs are born with thicker hydrogen envelopes, leading to more intense hydrogen burning shells as compared with their solar metallicity counterparts. We study the phase in which nuclear reactions are still important and find that nuclear energy sources play a key role during long periods of time, considerably increasing the cooling times from those predicted by standard white dwarf models. In particular, we find that for this metallicity and for white dwarf masses smaller than about 0.6 M ⊙, nuclear reactions are the main contributor to the stellar luminosity for luminosities as low as log (L/L⊙) ≃ -3.2. This, in turn, should have a noticeable impact in the white dwarf luminosity function of low-metallicity stellar populations.
format Articulo
Preprint
author Miller Bertolami, Marcelo Miguel
Althaus, Leandro Gabriel
García-Berro, E.
author_facet Miller Bertolami, Marcelo Miguel
Althaus, Leandro Gabriel
García-Berro, E.
author_sort Miller Bertolami, Marcelo Miguel
title Quiescent nuclear burning in low-metallicity white dwarfs
title_short Quiescent nuclear burning in low-metallicity white dwarfs
title_full Quiescent nuclear burning in low-metallicity white dwarfs
title_fullStr Quiescent nuclear burning in low-metallicity white dwarfs
title_full_unstemmed Quiescent nuclear burning in low-metallicity white dwarfs
title_sort quiescent nuclear burning in low-metallicity white dwarfs
publishDate 2013
url http://sedici.unlp.edu.ar/handle/10915/85519
work_keys_str_mv AT millerbertolamimarcelomiguel quiescentnuclearburninginlowmetallicitywhitedwarfs
AT althausleandrogabriel quiescentnuclearburninginlowmetallicitywhitedwarfs
AT garciaberroe quiescentnuclearburninginlowmetallicitywhitedwarfs
bdutipo_str Repositorios
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