Artículo
The effect of 22NE diffusion in the evolution and pulsational properties of white dwarfs with solar metallicity progenitors
Camisassa, María Eugenia
; Althaus, Leandro Gabriel
; Corsico, Alejandro Hugo
; Vinyoles, Núria; Serenelli, Aldo M.; Isern, Jordi; Miller Bertolami, Marcelo Miguel
; García Berro, E.
Fecha de publicación:
06/2016
Editorial:
IOP Publishing
Revista:
Astrophysical Journal
ISSN:
0004-637X
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Because of the large neutron excess of 22Ne, sedimentation of this isotope occurs rapidly in the interior of white dwarfs. This process releases an additional amount of energy, thus delaying the cooling times of the white dwarf. This influences the ages of different stellar populations derived using white dwarf cosmochronology. Furthermore, the overabundance of 22Ne in the inner regions of the star modifies the Brunt–Väisälä frequency, thus altering the pulsational properties of these stars. In this work we discuss the impact of 22Ne sedimentation in white dwarfs resulting from solar metallicity progenitors (Z = 0.02). We performed evolutionary calculations of white dwarfs with masses of 0.528, 0.576, 0.657, and 0.833 M derived from full evolutionary computations of their progenitor stars, starting at the zero-age main sequence all the way through the central hydrogen and helium burning, the thermally pulsing asymptotic giant branch (AGB), and post-AGB phases. Our computations show that at low luminosities (log 4.25 ( ) L L - ), 22Ne sedimentation delays the cooling of white dwarfs with solar metallicity progenitors by about 1 Gyr. Additionally, we studied the consequences of 22Ne sedimentation on the pulsational properties of ZZ Ceti white dwarfs. We find that 22Ne sedimentation induces differences in the periods of these stars larger than the present observational uncertainties, particularly in more massive white dwarfs.
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Articulos(IALP)
Articulos de INST.DE ASTROFISICA LA PLATA
Articulos de INST.DE ASTROFISICA LA PLATA
Citación
Camisassa, María Eugenia; Althaus, Leandro Gabriel; Corsico, Alejandro Hugo; Vinyoles, Núria; Serenelli, Aldo M.; et al.; The effect of 22NE diffusion in the evolution and pulsational properties of white dwarfs with solar metallicity progenitors; IOP Publishing; Astrophysical Journal; 823; 158; 6-2016; 1-8
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