标题： 利用发射线多重线研究精细结构常数的变化 显示英文标题

标题： Studying the Variation of the Fine Structure Constant Using Emission Line Multiplets

摘要： 作为Bahcall等人（2004年）方法的扩展，用于研究精细结构常数的时间依赖性，我们描述了一种基于不同离子禁线多重态新观测的方法。我们从低红移范围0.035 < z < 0.281的14个塞弗特1.5型星系样本中获得[Ne III]、[Ne V]、[O III]、[OI]和[SII]多重态精细结构跃迁的光学光谱。每个源和每个多重态都独立分析以确定可能的误差。通过对样本取平均值，我们得到保守的结果α^2(t)/\alpha ^2(0) = 1.0030±0.0014。然而，由于我们的样本规模有限且拟合技术较为简单，主要目的是展示发射线研究精细结构常数时间变化的范围和优势。这种方法可以进一步扩展和推广为类似于吸收线方法的“多多重发射线方法”。为此，我们注意到所选离子发射线比值的理论限制是精确已知的，并提供了严格的选取标准。我们还讨论了其他一些禁线和允许线，这些线可能构成下一代8米级望远镜高分辨率仪器更严格研究的基础。 显示英文摘要

摘要： As an extension of the method by Bahcall et al. (2004) to investigate the time dependence of the fine structure constant, we describe an approach based on new observations of forbidden line multiplets from different ionic species. We obtain optical spectra of fine structure transitions in [Ne III], [Ne V], [O III], [OI], and [SII] multiplets from a sample of 14 Seyfert 1.5 galaxies in the low-z range 0.035 < z < 0.281. Each source and each multiplet is independently analyzed to ascertain possible errors. Averaging over our sample, we obtain a conservative value alpha^2(t)/\alpha^2(0) = 1.0030+-0.0014. However, our sample is limited in size and our fitting technique simplistic as we primarily intend to illustrate the scope and strengths of emission line studies of the time variation of the fine structure constant. The approach can be further extended and generalized to a "many-multiplet emission line method" analogous in principle to the corresponding method using absorption lines. With that aim, we note that the theoretical limits on emission line ratios of selected ions are precisely known, and provide well constrained selection criteria. We also discuss several other forbidden and allowed lines that may constitute the basis for a more rigorous study using high-resolution instruments on the next generation of 8 m class telescopes.