论文标题
使用Iris Si IV的非热速度的中心到中线变化
The Center-to-Limb Variation of Non-Thermal Velocities using IRIS Si IV
论文作者
论文摘要
我们使用来自界面区域成像光谱仪（IRIS）的各种高空间，时间和光谱分辨率观测来研究静音中的非热速度。我们使用光学上的细线（SI IV1393.7Å）和几乎是高斯的选择线轮廓将分析重点放在过渡区域上。我们发现使用具有不同暴露时间的不同观测值（范围为5-30 s）的不同观测值。观察到靠近肢体的非热速度的分布在20 km s $^{ - 1} $的峰值上达到峰值，而光盘观测显示峰值约为15 km s $^{ - 1} $。分布也不同。如前所述，非热速度的总体变化与线的强度相关。盘速度比以前的大多数观察值小。通常，我们发现非热速度与选定的暴露时间无关。 Si IV线似乎没有表现出任何明显的不透明度效应。我们得出的结论是，这些多普勒运动主要是横向到径向方向的。从这些虹膜观察结果中验证了导致这种变化的摇摆/扭转运动的可能性。
We study the non-thermal velocities in the quiet-sun using various high spatial, temporal, and spectral resolution observations from the Interface Region Imaging Spectrograph (IRIS). We focus our analysis on the transition region using the optically thin line (Si IV 1393.7 Å), and select line profiles that are nearly Gaussian. We find evidence of a centre-to-limb variation using different observations having different exposure times, ranging from 5-30 s. The distribution of non-thermal velocities close to the limb are observed to peak around 20 km s$^{-1}$ while the disc observations show a peak around 15 km s$^{-1}$. The distributions are also different. The overall variation in the non-thermal velocities are correlated with the intensity of the line, as found previously. The on-disc velocities are smaller than most previous observations. In general, we find that the non-thermal velocities are independent of the selected exposure times. The Si IV lines didn't seem to exhibit any significant opacity effects. We conclude that these Doppler motions are mostly transverse to the radial direction. The possibility of swaying/torsional motions leading to such variations are validated from these IRIS observations.
