Artículo
On the formation of hot DQ white dwarfs
Althaus, Leandro Gabriel
; García Berro, Enrique; Corsico, Alejandro Hugo
; Miller Bertolami, Marcelo Miguel
; Romero, Alejandra Daniela
Fecha de publicación:
12/2009
Editorial:
IOP Publishing
Revista:
Astrophysical Journal
ISSN:
0004-637X
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
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.
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Articulos de INST.DE ASTROFISICA LA PLATA
Articulos de INST.DE ASTROFISICA LA PLATA
Citación
Althaus, Leandro Gabriel; García Berro, Enrique; Corsico, Alejandro Hugo; Miller Bertolami, Marcelo Miguel; Romero, Alejandra Daniela; On the formation of hot DQ white dwarfs; IOP Publishing; Astrophysical Journal; 693; 1; 12-2009; L23-L26
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