ANALYSIS OF CORONAL RAIN OBSERVED BY IRIS, HINODE/SOT, AND SDO/AIA: TRANSVERSE OSCILLATIONS, KINEMATICS, AND THERMAL EVOLUTION
ANALYSIS OF CORONAL RAIN OBSERVED BY IRIS, HINODE/SOT, AND SDO/AIA: TRANSVERSE OSCILLATIONS, KINEMATICS, AND THERMAL EVOLUTION
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DOI：
10.3847/0004-637x/827/1/39
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发表时间：
2016-08
期刊：
影响因子：
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通讯作者：
P. Kohutova;E. Verwichte
中科院分区：
文献类型：
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作者：
P. Kohutova;E. Verwichte
日冕雨是由冷等离子体凝结物沿沿着磁力线从日冕高处落下而形成的，主要发生在活动区日冕环中。最近的高分辨率观测表明，日冕雨比以前认为的要普遍得多，这表明它在色球-日冕质量循环中扮演着重要角色。本文分析了界面区成像光谱仪（IRIS）、日出太阳光学望远镜（SOT）和太阳动力学天文台（SDO）大气成像组件（AIA）在色球层和过渡区谱线上观测到的日冕雨的MHD振荡和运动学。两种不同的制度的横向振荡跟踪的雨：小规模的持续振荡驱动的连续操作过程和本地化的大规模振荡激发的瞬态机制。等离子体凝聚的运动速度从几km s-1到180 km s-1不等，加速度大大低于自由落体速率，这可能是由压力效应和环振荡产生的有质动力解释的。观察到的演变中的个别SDO/AIA带通的发射被发现表现出清晰的签名的等离子体逐渐冷却的循环顶部。我们确定的日冕环等离子体的温度演化，使用正则化反演恢复差分发射测量（DEM），并通过使用两个组件的合成DEM模型的SDO/AIA带通发射强度的正演模拟。推断的温度和密度的等离子体的顶点附近的演化是一致的极限环模型，并建议循环正在经历一系列的周期性重复加热冷凝循环。
Coronal rain composed of cool plasma condensations falling from coronal heights along magnetic field lines is a phenomenon occurring mainly in active region coronal loops. Recent high-resolution observations have shown that coronal rain is much more common than previously thought, suggesting its important role in the chromosphere-corona mass cycle. We present the analysis of MHD oscillations and kinematics of the coronal rain observed in chromospheric and transition region lines by the Interface Region Imaging Spectrograph (IRIS), the Hinode Solar Optical Telescope (SOT), and the Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA). Two different regimes of transverse oscillations traced by the rain are detected: small-scale persistent oscillations driven by a continuously operating process and localized large-scale oscillations excited by a transient mechanism. The plasma condensations are found to move with speeds ranging from few km s−1 up to 180 km s−1 and with accelerations largely below the free-fall rate, likely explained by pressure effects and the ponderomotive force resulting from the loop oscillations. The observed evolution of the emission in individual SDO/AIA bandpasses is found to exhibit clear signatures of a gradual cooling of the plasma at the loop top. We determine the temperature evolution of the coronal loop plasma using regularized inversion to recover the differential emission measure (DEM) and by forward modeling the emission intensities in the SDO/AIA bandpasses using a two-component synthetic DEM model. The inferred evolution of the temperature and density of the plasma near the apex is consistent with the limit cycle model and suggests the loop is going through a sequence of periodically repeating heating-condensation cycles.