A New Method to Comprehensively Diagnose Shock Waves in the Solar Atmosphere Based on Simultaneous Spectroscopic and Imaging Observations
A New Method to Comprehensively Diagnose Shock Waves in the Solar Atmosphere Based on Simultaneous Spectroscopic and Imaging Observations
复制标题
基于同步光谱和成像观测的太阳大气冲击波综合诊断新方法
DOI：
10.3847/1538-4357/aac0f8
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发表时间：
2018
影响因子：
4.9
通讯作者：
Wei Yong
中科院分区：
文献类型：
--
作者：
Ruan Wenzhi;Yan Limei;He Jiansen;Zhang Lei;Wang Linghua;Wei Yong
冲击波被认为在等离子体加热中起着重要作用。在太阳大气中，辐射强度和多普勒频移的时间跳跃已被确认为激波状。然而，对太阳大气中激波的定量诊断仍然缺乏，严重阻碍了对太阳大气激波耗散加热的理解。在这里，我们提出了一种新的方法来实现冲击定量诊断的目标，基于Rankine-Hugoniot方程，并利用同时成像和光谱观测的优势，例如，IRIS（界面区域成像光谱仪）。利用该方法可以得到激波候选的关键参数，如等离子体在上下游的整体速度和温度，传播速度和方向等。将该方法应用于IRIS观测到的候选冲击，首次定量地揭示了冲击的总体特征。还借助正演模型对该方法进行了测试，即，模拟冲击的虚拟观测。该方法得到的参数与模型中形成的激波参数一致，且与观察方向无关。因此，本文提出的方法适用于对太阳大气中观测到的激波进行定量和综合诊断。
Shock waves are believed to play an important role in plasma heating. The shock-like temporal jumps in radiation intensity and Doppler shift have been identified in the solar atmosphere. However, a quantitative diagnosis of the shocks in the solar atmosphere is still lacking, seriously hindering the understanding of shock dissipative heating of the solar atmosphere. Here, we propose a new method to realize the goal of the shock quantitative diagnosis, based on Rankine–Hugoniot equations and taking the advantages of simultaneous imaging and spectroscopic observations from, e.g., IRIS (Interface Region Imaging Spectrograph). Because of this method, the key parameters of shock candidates can be derived, such as the bulk velocity and temperature of the plasma in the upstream and downstream, the propagation speed and direction. The method is applied to the shock candidates observed by IRIS, and the overall characteristics of the shocks are revealed quantitatively for the first time. This method is also tested with the help of forward modeling, i.e., virtual observations of simulated shocks. The parameters obtained from the method are consistent with the parameters of the shock formed in the model and are independent of the viewing direction. Therefore, the method we proposed here is applicable to the quantitative and comprehensive diagnosis of the observed shocks in the solar atmosphere.