White dwarf mass distribution in the SDSS

We determined masses for the 7167 DA and 507 DB white dwarf stars classified as single and non-magnetic in Data Release 4 of the Sloan Digital Sky Survey (SDSS). We obtained revised Teff and log g determinations for the most massive stars by fitting the SDSS optical spectra with a synthetic spectra...

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Detalles Bibliográficos
Autores principales: Kepler, S. O., Kleinman, S. J., Nitta, A., Koester, D., Castanheira, B. G., Giovannini, O., Costa, A. F.M., Althaus, Leandro Gabriel
Formato: Articulo
Lenguaje:Inglés
Publicado: 2007
Materias:
Ciencias Astronómicas
White dwarfs
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83032
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
Descripción
Sumario:We determined masses for the 7167 DA and 507 DB white dwarf stars classified as single and non-magnetic in Data Release 4 of the Sloan Digital Sky Survey (SDSS). We obtained revised Teff and log g determinations for the most massive stars by fitting the SDSS optical spectra with a synthetic spectra grid derived from model atmospheres extending to log g = 10.0. We also calculate radii from evolutionary models and create volume-corrected mass distributions for our DA and DB samples. The mean mass for the DA stars brighter than g = 19 and hotter than Teff = 12 000 K is (M)DA ≃ 0.593 ± 0.016 M⊙. For the 150 DBs brighter than g = 19 and hotter than reff = 16000 K, we find (M)DB = 0.711 ±0.009M⊙. It appears the mean mass for DB white dwarf stars may be significantly larger than that for DAs. We also report the highest mass white dwarf stars ever found, up to 1.33 M⊙.

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