Spectral modeling of gaseous metal disks around DAZ white dwarfs
Spectral modeling of gaseous metal disks around DAZ white dwarfs
复制标题
DAZ 白矮星周围气态金属盘的光谱建模
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
T. Rauch
中科院分区：
文献类型：
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作者：
K. Werner;T. Nagel;T. Rauch
我们报告了我们对单个DAZ白矮星周围气体金属盘的首次非lte建模的尝试，这些白矮星最近被Gansicke等人发现，并被认为起源于一颗被破坏的小行星。我们假设一个由钙和氢组成的开普勒旋转粘性圆盘环，并计算了其详细的垂直结构和涌现谱。我们发现观测到的红外CaII发射三重态可以用一个位于潮汐破坏半径内R = 1.2 R⊙的缺氢气环来模拟，Teff≈6000 K，表面质量密度约为0.3 g/cm2。具有这种密度的圆盘，从中心白矮星延伸到R = 1.2 R⊙，其总质量为7 1021 g，相当于直径约160公里的小行星。
We report on our attempt for the first non-LTE modeling of gaseous metal disks around single DAZ white dwarfs recently discovered by Gansicke et al. and thought to originate from a disrupted asteroid. We assume a Keplerian rotating viscous disk ring composed of calcium and hydrogen and compute the detailed vertical structure and emergent spectrum. We find that the observed infrared CaII emission triplet can be modeled with a hydrogen-deficient gas ring located at R = 1.2 R⊙, inside of the tidal disruption radius, with Teff ≈ 6000 K and a low surface mass density of ≈ 0.3 g/cm2. A disk having this density and reaching from the central white dwarf out to R = 1.2 R⊙ would have a total mass of 7 1021 g, corresponding to an asteroid with ≈ 160km diameter.