The FeH F4 Δ-X4 Δ system. Creating a valuable diagnostic tool to explore solar and stellar magnetic fields
The FeH F4 Δ-X4 Δ system. Creating a valuable diagnostic tool to explore solar and stellar magnetic fields
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FeH F4 Δ-X4 Δ 系统创建了一个有价值的诊断工具来探索太阳和恒星磁场。
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
A. Lagg
中科院分区：
文献类型：
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作者：
N. Afram;S. Berdyugina;D. M. Fluri;S. Solanki;A. Lagg
上下文双原子分子谱线是研究冷恒星大气和太阳黑子内部结构的理想工具，因为它们的温度和压力敏感性通常高于原子谱线。Wing-Ford FeH F 4 Δ-X 4 Δ系统代表了这样一种双原子分子，此外，它对磁场高度敏感。然而，目前的理论描述，包括所涉及的分子常数，这些转变，仅基于强度测量，因为偏振观测尚未提供，直到现在，这限制了他们的诊断价值。此外，到目前为止，该理论已被优化，以再现能级和线强度，而不考虑磁灵敏度。目标。FeH F4 Δ-X4 Δ系统是由两个电子态之间的跃迁产生的，角动量的耦合介于Hund极限情况（a）和（B）之间.我们的目标是调查目前的理论描述的分子FeH的诊断能力。方法.利用最精确的哈密顿量，我们对该跃迁的分子塞曼效应进行了微扰计算，并计算了能级和跃迁的朗德因子。我们提取朗德因子的观测和计算的斯托克斯I和V配置文件的比较。某些谱线，最常见的是高磁灵敏度，表现出理论和观测之间的差异。我们用半经验方法扩展了理论模型，以获得能够再现许多有趣谱线的诊断工具。结果我们发现，目前的理论成功地再现了FeH F4 Δ-X4 Δ系统中大量谱线的磁性，而修正的哈密顿量使我们能够合成并成功地再现最敏感的谱线.因此，我们的观察提供了有价值的限制，确定经验分子常数和朗德因子。结论. FeH F4 Δ-X4 Δ系统是一种非常灵敏的磁诊断工具.这些谱线的偏振测量数据与强度测量相比，为我们研究太阳黑子和恒星黑子本影的最冷部分以及冷的活动矮星提供了更直接和详细的信息。
Context. Lines of diatomic molecules are ideal tools for studying cool stellar atmospheres and the internal structure of sunspots and starspots, given their temperature and pressure sensitivities, which are typically higher than in atomic lines. The Wing-Ford FeH F 4 Δ-X 4 Δ system represents such a diatomic molecule that is, in addition, highly sensitive to magnetic fields. The current theoretical description of those transitions that include the involved molecular constants, however, are only based on intensity measurements because polarimetric observations have not been available until now, which limits their diagnostic value. Furthermore, the theory has so far been optimized to reproduce energy levels and line strengths without taking magnetic sensitivities into account. Aims. The FeH F 4 Δ-X 4 Δ system is produced by transitions between two electronic states with the coupling of the angular momenta that is intermediate between limiting Hund's cases (a) and (b). Our goal is to investigate the diagnostic capabilities of the current theoretical description of the molecule FeH. Methods. Using the most precise available Hamiltonian, we carried out the perturbation calculation of the molecular Zeeman effect for this transition and computed the Lande factors of the energy levels and of transitions. We extracted Lande factors from a comparison of observed and calculated Stokes I and V profiles. Certain spectral lines, most frequently with high magnetic sensitivity, exhibited discrepancies between the theory and observations. We extended the theoretical model with a semi-empirical approach to obtain a diagnostic tool that is able to reproduce many of the interesting spectral lines. Results. We find that the current theory successfully reproduces the magnetic properties of a large number of lines in the FeH F 4 Δ-X 4 Δ system and that the modified Hamiltonian allows us to synthesize and successfully reproduce the most sensitive lines. Thus, our observations have provided valuable constraints for determining empirical molecular constants and Lande factors. Conclusions. The FeH F 4 Δ-X 4 Δ system is found to be a very sensitive magnetic diagnostic tool. Polarimetric data of these lines, in contrast to intensity measurements, provide us with more direct and detailed information to study the coolest parts of sunspot and starspot umbrae, as well as cool active dwarfs.