White Dwarf Atmospheres.
نویسندگان
چکیده
منابع مشابه
Rare White dwarf stars with carbon atmospheres
White dwarfs represent the endpoint of stellar evolution for stars with initial masses between approximately 0.07 M⊙ and 8-10 M⊙, where M⊙ is the mass of the Sun (more massive stars end their life as either black holes or neutron stars). The theory of stellar evolution predicts that the majority of white dwarfs have a core made of carbon and oxygen, which itself is surrounded by a helium layer ...
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We present a detailed calculation of model atmospheres for DA white dwarfs. Our atmosphere code solves the atmosphere structure in local thermodynamic equilibrium with a standard partial linearization technique, which takes into account the energy transfer by radiation and convection. This code incorporates recent improved and extended data base of collision induced absorption by molecular hydr...
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The existence of carbon in cool He white dwarf (WD) atmospheres has been known for a relatively long time[5]. The presence of carbon in these atmospheres is explained by convective dredge up of interior carbon [6]. Pelletier et al. (1986) presented the first detailed calculations of this process and showed that carbon diffuses upwards from the core into the base of the He-rich envelope where it...
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We investigate the importance of the pseudo-continuum bound-free opacity from hydrogen atoms in the atmospheres of cool white dwarfs. This source of absorption, when calculated by the occupation probability formalism applied in the modeling of white dwarf atmospheres with Teff < 17000K, dominates all other sources of opacity at optical wavelengths. This is unrealistic and not observed. On the o...
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About 3% of all known white dwarfs have strong magnetic fields between 10 and 10 Gauss (Wickramasinghe & Ferrario 2000, Jordan 2001). The detailed surface structure of the magnetic field can be inferred from time-resolved spectro-polarimetric observations, which give integrals of the polarized radiation over the stellar surface visible at a given rotational phase. Because the magnetic field var...
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ژورنال
عنوان ژورنال: The Astronomical Journal
سال: 1965
ISSN: 0004-6256
DOI: 10.1086/109834