标题： 铁III的原子数据和光谱模型 显示英文标题

标题： Atomic data and spectral model for Fe III

摘要： 我们提供了来自大规模计算的新原子数据（辐射跃迁速率和碰撞强度）以及用于Fe III的非LTE光谱模型。 该模型与观测到的天体发射光谱非常吻合，与之前模型与观测结果存在较大差异形成鲜明对比。 目前的原子计算采用了多种原子物理方法的组合，例如相对论Hatree-Fock、Thomas-Fermi-Dirac势以及A值和中间耦合框架变换的R矩阵与Dirac R矩阵计算。 我们研究了每种方法的优点和缺点。 发现Dirac R矩阵的碰撞强度与观测结果有很好的一致性，比之前可用的模型有了显著改进。 相比之下，LS耦合R矩阵的转换在约10^4 K时未能产生准确的有效碰撞强度，尽管使用了非常大的组态展开，但由于在碰撞强度的近阈值共振中对自旋-轨道效应的处理有限。 本研究证明，现在可以获取低电离铁峰物种的精确原子数据。 显示英文摘要

摘要： We present new atomic data (radiative transitions rates and collision strengths) from large scale calculations and a non-LTE spectral model for Fe III. This model is in very good agreement with observed astronomical emission spectra, in contrast with previous models that yield large discrepancies with observations. The present atomic computations employ a combination of atomic physics methods, e.g. relativistic Hatree-Fock, the Thomas-Fermi-Dirac potential, and Dirac-Fock computation of A-values and R-matrix with intermediate coupling frame transformation and Dirac R-matrix. We study the advantages and shortcomings of each method. It is found that the Dirac R-matrix collision strengths yield excellent agreement with observations, much improved over previously available models. By contrast, the transformation of LS-coupling R-matrix fails to yield accurate effective collision strengths at around 10^4 K, despite using very large configuration expansions, due to the limited treatment of spin-orbit effects in the near threshold resonances of the collision strengths. The present work demonstrates that accurate atomic data for low ionization iron-peak species is now within reach.