论文标题
在太阳耀斑的早期观测和建模中，He I10830Å的吸收增强的比较
Comparison of Enhanced Absorption in He I 10830 Å in Observations and Modeling During the Early Phase of a Solar Flare
论文作者
论文摘要
He I10830Å三重态是色球活性的非常有用的指标，因为氦是太阳大气中第二大元素。利用大熊太阳能天文台（BBSO）的1.6 m Goode太阳能望远镜（GST）的高分辨率，先前的观测结果表明，有两种M级火力的吸收增强的明确证据，而不是典型的吸收，而不是典型的观察。在这项研究中，我们分析了He I 1083010830Å在数值模型中的发射的演变，并将其与观测值进行了比较。这些模型代表了从F-Chroma数据库获得的Radyn仿真结果。我们考虑具有接近2013年8月17日耀斑事件的观察性估计的注入电子光谱参数的模型（$δ= 8 $，$ e_c = \ {15,20 \} $ kev，$ f = \ {1 \ {1 \ {1 \ times times times times times 10^{11} {11} {11}，3 \ \ times {} $ {11} $ {细节以及其他可用模型。从最大强度降低（与观察到的值为-13.7％相比，最大强度降低）和时间变化的趋势（初始吸收阶段随后是发射），建模结果与观察结果非常吻合。所有模型均表明，在初始阶段，HE I 1083010830Å过渡的上下级别种群的数量密度增加和降低，从而增强了不透明度并形成吸收特征。型号表明，高度为1.3-1.5毫米的温度和免费电子密度应大于$ \ sim 10^4 $ K和$ 6 \ times 10^{11} $ cm $ $^{ - 3} $阈值，以使生产线开始排放。
The He I 10830 Å triplet is a very informative indicator of chromospheric activities as the helium is the second most abundant element in the solar atmosphere. Taking advantage of the high resolution of the 1.6 m Goode Solar Telescope (GST) at Big Bear Solar Observatory (BBSO), previous observations have shown clear evidence of the enhanced absorption, instead of typically-observed emission, for two M-class flares. In this study, we analyze the evolution of the He I 10830 10830 Å emission in numerical models and compare it with observations. The models represent the RADYN simulation results obtained from the F-CHROMA database. We consider the models with the injected electron spectra parameters close to observational estimates for the 2013-August-17 flare event ($δ=8$, $E_c = \{15,20\}$ keV, $F=\{1\times 10^{11}, 3\times{}10^{11}\}$ erg cm$^{-2}$) in detail, as well as other available models. The modeling results agree well with observations, in the sense of both the maximum intensity decrease (-17.1%, compared to the observed value of -13.7%) and the trend of temporal variation (initial absorption phase followed by the emission). All models demonstrate the increased number densities and decreased ratio of the upper and lower level populations of He I 10830 10830 Å transition in the initial phase, which enhances the opacity and forms an absorption feature. Models suggest that the temperatures and free electron densities at heights of 1.3-1.5 Mm should be larger than $\sim 10^4$ K and $6\times 10^{11}$ cm$^{-3}$ thresholds for the line to start being in emission.
