On the formation of hot DQ white dwarfs

We present the first full evolutionary calculations aimed at exploring the origin of hot DQ white dwarfs. These calculations consistently cover the whole evolution from the born-again stage to the white dwarf cooling track. Our calculations provide strong support for the diffusive/convective mixing...

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Detalles Bibliográficos
Autores principales: Althaus, Leandro Gabriel, García Berro, Enrique, Córsico, Alejandro Hugo, Miller Bertolami, Marcelo Miguel, Romero, Alejandra Daniela
Formato: Articulo
Lenguaje:Inglés
Publicado: 2009
Materias:
Ciencias Astronómicas
Stars: evolution
Stars: interiors
stars: individual
white dwarfs
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/82745
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-82745
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: individual
white dwarfs
spellingShingle Ciencias Astronómicas
Stars: evolution
Stars: interiors
stars: individual
white dwarfs
Althaus, Leandro Gabriel
García Berro, Enrique
Córsico, Alejandro Hugo
Miller Bertolami, Marcelo Miguel
Romero, Alejandra Daniela
On the formation of hot DQ white dwarfs
topic_facet Ciencias Astronómicas
Stars: evolution
Stars: interiors
stars: individual
white dwarfs
description We present the first full evolutionary calculations aimed at exploring the origin of hot DQ white dwarfs. These calculations consistently cover the whole evolution from the born-again stage to the white dwarf cooling track. Our calculations provide strong support for the diffusive/convective mixing picture for the formation of hot DQs. We find that the hot DQ stage is a short-lived stage and that the range of effective temperatures where hot DQ stars are found can be accounted for by different masses of residual helium and/or different initial stellar masses. In the frame of this scenario, a correlation between the effective temperature and the surface carbon abundance in DQs should be expected, with the largest carbon abundances expected in the hottest DQs. From our calculations, we suggest that most of the hot DQs could be the cooler descendants of some PG 1159 stars characterized by He-rich envelopes markedly smaller than those predicted by the standard theory of stellar evolution. At least for one hot DQ, the high-gravity white dwarf SDSS J142625.70+575218.4, an evolutionary link between this star and the massive PG 1159 star H1504+65, is plausible.
format Articulo
Articulo
author Althaus, Leandro Gabriel
García Berro, Enrique
Córsico, Alejandro Hugo
Miller Bertolami, Marcelo Miguel
Romero, Alejandra Daniela
author_facet Althaus, Leandro Gabriel
García Berro, Enrique
Córsico, Alejandro Hugo
Miller Bertolami, Marcelo Miguel
Romero, Alejandra Daniela
author_sort Althaus, Leandro Gabriel
title On the formation of hot DQ white dwarfs
title_short On the formation of hot DQ white dwarfs
title_full On the formation of hot DQ white dwarfs
title_fullStr On the formation of hot DQ white dwarfs
title_full_unstemmed On the formation of hot DQ white dwarfs
title_sort on the formation of hot dq white dwarfs
publishDate 2009
url http://sedici.unlp.edu.ar/handle/10915/82745
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AT corsicoalejandrohugo ontheformationofhotdqwhitedwarfs
AT millerbertolamimarcelomiguel ontheformationofhotdqwhitedwarfs
AT romeroalejandradaniela ontheformationofhotdqwhitedwarfs
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