Line Intensities and Molecular Opacities of the FeH F 4Δi-X 4Δi Transition
Line Intensities and Molecular Opacities of the FeH F 4Δi-X 4Δi Transition
复制标题
FeH F 4Δi-X 4Δi 跃迁的线强度和分子不透明度
DOI：
10.1086/376791
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
P. Bernath
中科院分区：
文献类型：
--
作者：
M. Dulick;C. Bauschlicher;A. Burrows;C. Sharp;R. S. Ram;P. Bernath;P. Bernath
计算了FeH的F4 Δ i-X4 Δi跃迁的谱线和不透明度.这种跃迁的0-0波段是在M型恒星、太阳黑子和褐矮星中看到的翼-福特波段的原因。每条线的新爱因斯坦A值是基于电子跃迁偶极矩的高级从头计算。对于Hund情况（a）和（B）耦合极限，导出了必要的转动线强度因子（Hönl-London因子）。一组新的光谱常数来自现有的FeH项值为v = 0，1，和2水平的X和F状态。使用这些常数，外推的长期价值产生的v = 3和4和J值高达50.5。v ≤ 4的25个振动带的线列表（包括爱因斯坦A值）是使用实验和外推项值的合并列表生成的。FeH谱线表被用来计算在L和M矮大气中遇到的温度和压力范围内的分子不透明度。L5矮星2 MASS-1507的光谱能量分布的计算值与观测值吻合较好。
We calculate new line lists and opacities for the F 4Δi-X 4Δi transition of FeH. The 0-0 band of this transition is responsible for the Wing-Ford band seen in M-type stars, sunspots, and brown dwarfs. The new Einstein A-values for each line are based on a high-level ab initio calculation of the electronic transition dipole moment. The necessary rotational line strength factors (Hönl-London factors) are derived for both the Hund's case (a) and (b) coupling limits. A new set of spectroscopic constants was derived from the existing FeH term values for v = 0, 1, and 2 levels of the X and F states. Using these constants, extrapolated term values were generated for v = 3 and 4 and for J-values up to 50.5. The line lists (including Einstein A-values) for the 25 vibrational bands with v ≤ 4 were generated using a merged list of experimental and extrapolated term values. The FeH line lists were used to compute the molecular opacities for a range of temperatures and pressures encountered in L and M dwarf atmospheres. Good agreement was found between the computed and observed spectral energy distribution of the L5 dwarf 2MASS-1507.