论文标题
不同光谱型恒星中锌的非LTE丰度和银河系[Zn/Fe]趋势基于量子力学数据
Non-LTE abundances of zinc in different spectral type stars and the Galactic [Zn/Fe] trend based on quantum-mechanical data on inelastic processes in zinc-hydrogen collisions
论文作者
论文摘要
我们基于最新的光电子横截面，电子影响激发速率以及Zn I + H I + H I和Zn II + H-碰撞的速率系数，提出了一个新的模型原子。使用基于Born-oppenheimer方法的多通道量子渐近处理计算后者。第一次对两个非常金属贫穷的参考星的紫外线（UV）光谱进行了非LTE分析，HD 84937和HD 140283。我们发现，从resonance Zn I 2138 A线，下属线和Zn ii ii ii的resonance Zn i 2138 A Line 1138 A Line 1138。在这两颗恒星中，非LTE均导致Zn I的平均丰度更高，而对于Zn II线，非LTE校正较小，不超过0.06 DEX。在高分辨率光谱中，使用Zn I线，我们确定了在-2.5 <[fe/h] <0.2金属度范围内的80颗恒星样品的非LTE丰度。 [Zn/fe]与[Fe/H]图显示了一个倾角，在大多数金属贫困的恒星中[Zn/fe] = 0.3，[Fe/H] = -1.2的接近 - 极值，厚磁盘中的[Zn/fe]最高为0.3。接近 - 极性的金属性恒星平均具有下极[Zn/H] = -0.1。锌的非LTE丰度首次得出了七个参考f对B型恒星的参考。我们提供非LTE丰度校正的网格。
We present a new model atom of Zn I-II based on the most up-to-date photoionisation cross-sections, electron-impact excitation rates, and rate coefficients for the Zn I + H I and Zn II + H- collisions. The latter were calculated using the multi-channel quantum asymptotic treatment based on the Born-Oppenheimer approach. Non-LTE analysis was performed for the first time for lines of Zn I and Zn II in the ultraviolet (UV) spectra of two very metal-poor reference stars, HD 84937 and HD 140283. We found consistent non-LTE abundance from the resonance Zn I 2138 A line, the subordinate lines, and the lines of Zn II. In both stars, non-LTE leads to 0.17 dex higher average abundance from Zn I, while, for Zn II lines, non-LTE corrections are minor and do not exceed 0.06 dex. Using lines of Zn I in the high-resolution spectra, we determined the non-LTE abundances for a sample of 80 stars in the -2.5 < [Fe/H] < 0.2 metallicity range. The [Zn/Fe] versus [Fe/H] diagram reveals a dip, with [Zn/Fe] = 0.3 in the most metal-poor stars, a close-to-solar value for [Fe/H] = -1.2, and increasing [Zn/Fe] up to 0.3 in the thick disk stars. The close-to-solar metallicity stars have subsolar [Zn/H] = -0.1, on average. Non-LTE abundances of zinc were derived for the first time for seven reference F to B-type stars. We provide a grid of the non-LTE abundance corrections.
