This review covers the techniques, observations, and inferences of solar flare spectroscopy. It is not a spectroscopist's view of solar flares but rather a solar flare physicist's view of spectroscopy. Spectroscopy is carried out across the electromagnetic spectrum, but this review emphasizes the optical to soft X-ray part of the spectrum and discusses results from spectroscopy applied to the preflare, impulsive, and gradual phases, as well as a few highlights from modeling. ▪The main spectroscopic signatures of the preflare phase are line broadening in optically thin ultraviolet to soft X-ray lines and small Doppler shifts in active region filaments that are becoming unstable.▪In the impulsive phase, fast upflows of heated plasma into the corona and slow downflows of cooler chromospheric plasma take place at the sites of strong chromospheric energy deposition.▪Radiation-hydrodynamic modeling of optically thick spectral lines gives a picture of an impulsive-phase chromosphere with a dense, heated layer deep in the atmosphere and an overlying, downward moving condensation that is partially optically thin.▪Gradual-phase observations show us the heated coronal plasma cooling and draining but also provide evidence for ongoing slow energy input and slow upflows in other locations.▪Interesting hints of non-Maxwellian and nonequilibrium plasmas have been found, along with possible evidence of plasma turbulence from line broadening.

中文翻译：

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 太阳耀斑光谱


这篇综述涵盖了太阳耀斑光谱的技术、观察和推理。这不是光谱学家对太阳耀斑的看法，而是太阳耀斑物理学家对光谱学的看法。光谱学是在整个电磁波谱中进行的，但本文强调光谱的光学到软 X 射线部分，并讨论了应用于预耀斑、脉冲和渐变阶段的光谱学结果，以及建模的一些亮点。▪预耀斑阶段的主要光谱特征是在光学薄的紫外线到柔和的 X 射线线中的谱线展宽和变得不稳定的活动区细丝中的小多普勒频移。▪在脉冲相中，加热的等离子体快速上升到日冕中，而较冷的色层等离子体缓慢下降发生在强色球能量沉积的部位。▪光学厚谱线的辐射流体动力学建模给出了脉冲相的图片色球层在大气深处有一个致密的加热层和一个上覆的、向下移动的凝结物，部分光学上很薄。▪渐进相位的观测向我们展示了加热的日冕等离子体冷却和排水，但也为其他位置持续缓慢的能量输入和缓慢的上升提供了证据。▪已经发现了非麦克斯韦和非平衡等离子体的有趣迹象，以及谱线展宽引起的等离子体湍流的可能证据。