论文标题
关于\ ion {si} {4}线（$λ$ 1394/$λ$ 1403）的比率
On the ratios of \ion{Si}{4} lines ($λ$1394/$λ$1403) in an emerging flux region
论文作者
论文摘要
在$λ$ 1394和1403Å形成的\ ion {si} {4}的共振线对于在界面区域成像光谱仪（IRIS）观察中，对于太阳能过渡区域的诊断最重要的是最重要的。研究这些线的强度比（1394Å/1403Å）预计在光学较薄的情况下被预计为两个，有助于我们诊断观察到的血浆的光厚度。在这里，我们研究了在活性区域出现期间记录了四天的31个虹膜射手中强度比的分布的演变。我们发现，在开发的早期阶段，大多数像素显示强度比小于两个。但是，随着活动区域的发展，越来越多的像素显示了比率接近两个的比率。此外，还有大量的像素，比例值大于2。在活动区域的进化阶段，比例小于两个的像素位于外围，而值大于2的像素则位于核心。但是，对于安静的太阳区域，无论磁盘上的位置如何，获得的强度比都接近两个。我们的发现表明，在磁通出现的早期阶段，在活动区域观察到的\ ion {si} {4}线受到不透明度的影响。这里获得的结果可能对太阳大气的建模具有重要意义，包括活跃区域的初始阶段以及安静的太阳。
The resonance lines of \ion{Si}{4} formed at $λ$1394 and 1403 Å are the most critical for the diagnostics of the solar transition region in the observations of the Interface Region Imaging Spectrograph (IRIS). Studying the intensity ratios of these lines (1394Å/1403Å), which under optically thin condition is predicted to be two, helps us to diagnose the optical thickness of the plasma being observed. Here we study the evolution of the distribution of intensity ratios in 31 IRIS rasters recorded for four days during the emergence of an active region. We found that during the early phase of the development, the majority of the pixels show intensity ratios smaller than two. However, as the active region evolves, more and more pixels show the ratios closer to two. Besides, there are a substantial number of pixels with ratio values larger than 2. At the evolved stage of the active region, the pixels with ratios smaller than two were located on the periphery, whereas those with values larger than 2 were in the core. However, for quiet Sun regions, the obtained intensity ratios were close to two irrespective of the location on the disk. Our findings suggest that the \ion{Si}{4} lines observed in active regions are affected by the opacity during the early phase of the flux emergence. The results obtained here could have important implications for the modelling of the solar atmosphere, including the initial stage of the emergence of an active region as well as quiet Sun.
