The Nature of High-frequency Oscillations Associated with Short-lived Spicule-type Events
The Nature of High-frequency Oscillations Associated with Short-lived Spicule-type Events
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DOI：
10.3847/1538-4357/ac1a12
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发表时间：
2021-10
期刊：
影响因子：
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通讯作者：
J. Shetye;E. Verwichte;M. Stangalini;J. G. Doyle
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作者：
J. Shetye;E. Verwichte;M. Stangalini;J. G. Doyle
我们研究了CRISP成像光谱偏振仪(CRISP)的高分辨率光谱和成像观测，以研究色球针状物类型事件的动力学。人们普遍认为，色球精细结构是几种类型的磁流体(MHD)振荡的波导，可以将能量从太阳的下层传输到上层。我们提供了与针刺型事件相关的30个高频波的统计研究。这些高频振荡包括横向运动的两个组成部分：天空平面(POS)运动和视线(LOS)运动。我们聚焦于单个孤立针状体，使用时间距离分析跟踪POS，并使用多普勒信息跟踪LOS方向。我们使用矩分析来找出这两个运动之间的关系。这两个运动的组合表明，波具有螺旋结构。这些振荡在沿结构的点之间没有相位差。这可能是因为振荡是驻留模式，或者传播主要是在垂直方向上。有证据表明，快速磁声波锋在这些结构中传播。总之，我们假设，通过磁声波的压缩和稀疏可能会影响针叶型事件的出现，这不仅是通过将它们移入和移出谱线的机翼，而且是通过创造密度增强和增加Hα线的不透明度。
We investigate high-resolution spectroscopic and imaging observations from the CRisp Imaging SpectroPolarimeter (CRISP) instrument to study the dynamics of chromospheric spicule-type events. It is widely accepted that chromospheric fine structures are waveguides for several types of magnetohydrodynamic (MHD) oscillations, which can transport energy from the lower to upper layers of the Sun. We provide a statistical study of 30 high-frequency waves associated with spicule-type events. These high-frequency oscillations have two components of transverse motions: the plane-of-sky (POS) motion and the line-of-sight (LOS) motion. We focus on single isolated spicules and track the POS using time–distance analysis and in the LOS direction using Doppler information. We use moment analysis to find the relation between the two motions. The composition of these two motions suggests that the wave has a helical structure. The oscillations do not have phase differences between points along the structure. This may be the result of the oscillation being a standing mode, or that propagation is mostly in the perpendicular direction. There is evidence of fast magnetoacoustic wave fronts propagating across these structures. To conclude, we hypothesize that the compression and rarefaction of passing magnetoacoustic waves may influence the appearance of spicule-type events, not only by contributing to moving them in and out of the wing of the spectral line but also through the creation of density enhancements and an increase in opacity in the Hα line.