X-ray spectra of the Fe-L complex III. Systematic uncertainties in atomic data
X-ray spectra of the Fe-L complex III. Systematic uncertainties in atomic data
复制标题
Fe-L 配合物 III 的 X 射线光谱。
DOI：
10.1051/0004-6361/202039943
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发表时间：
2022
影响因子：
6.5
通讯作者：
Gu L
中科院分区：
文献类型：
--
作者：
Gu L
X射线天文学界越来越多地要求对等离子体代码中使用的原子数据产生的系统不确定性进行定量估计。虽然已经有几项研究使用理论计算来研究原子数据的不确定性，但一般来说，这项任务没有普遍接受的解决方案。我们提出了一种新的方法来估计线发射率的碰撞等离子体的当前模型的不确定性，主要是基于一个专门的分析所观察到的高分辨率光谱的恒星日冕和星系团。我们发现，系统的不确定性的观测线一致地显示与模型线通量的关系，适当占离子浓度计算的额外的不确定性后。光谱中的强谱线一般都能更好地再现，这表明主要跃迁的原子数据和模型比次要跃迁的数据和模型更准确。这种基本的离子交换关系被发现是大致独立的源属性，线的位置，离子种类，和线的形成过程。我们进一步将我们的方法应用到碰撞等离子体源的模拟XRISM和Athena观测中，并讨论了不确定性对这些光谱解释的影响。典型的不确定度是1-2%的温度和3-20%的O，Ne，Fe，Mg和Ni的丰度。
There has been a growing request from the X-ray astronomy community for a quantitative estimate of systematic uncertainties originating from the atomic data used in plasma codes. Though there have been several studies looking into atomic data uncertainties using theoretical calculations, in general, there is no commonly accepted solution for this task. We present a new approach for estimating uncertainties in the line emissivities for the current models of collisional plasma, mainly based upon a dedicated analysis of observed high resolution spectra of stellar coronae and galaxy clusters. We find that the systematic uncertainties of the observed lines consistently show an anticorrelation with the model line fluxes, after properly accounting for the additional uncertainties from the ion concentration calculation. The strong lines in the spectra are in general better reproduced, indicating that the atomic data and modeling of the main transitions are more accurate than those for the minor ones. This underlying anticorrelation is found to be roughly independent of source properties, line positions, ion species, and the line formation processes. We further applied our method to the simulated XRISM and Athena observations of collisional plasma sources and discuss the impact of uncertainties on the interpretation of these spectra. The typical uncertainties are 1–2% on temperature and 3–20% on abundances of O, Ne, Fe, Mg, and Ni.