Two-horn quiescent prominence observed in H a and Mg II h&k lines with THEMIS and IRIS
Two-horn quiescent prominence observed in H a and Mg II h&k lines with THEMIS and IRIS
复制标题
在 Ha 和 Mg II h 中观察到双角静止日珥
DOI：
10.1051/0004-6361/202345970
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发表时间：
2023
影响因子：
6.5
通讯作者：
Barczynski K
中科院分区：
文献类型：
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作者：
Barczynski K
日珥是日冕中具有快速演化精细结构的冷等离子体填充的大磁结构，目的利用高分辨率界面区成像光谱仪（IRIS）和多光谱仪（MTR），更好地了解静止日珥精细结构中的等离子体条件，包括在腔底部观察到的两个瞬态角。Télescope Heliographique pour l'Etude du Magnétisme et des Instabilités Solaires（THEMIS）方法我们分析了THEMIS和IRIS在Hα和Mg II中获得的光谱，并将它们与23 940个一维辐射传输模型的网格进行比较，包括顺磁-电晕过渡区（PCTR）。Mg II在每个像素中的完整观测轮廓完全由具有×RMS（交叉RMS;滚动均方根（rRMS）方法的改进版本）的合成轮廓拟合。当RMS低于某个阈值时，我们从最适合所观察到的线轮廓的模型的参数恢复等离子体条件。这一标准是满足在两个地区（角和边缘的突出）的线轮廓一般可以被描述为单peaked.ResultsThe一维模型表明，两种不同的模型大气对应于这两个区域。在边缘的区域被发现主要与等温和等压模型拟合，而其他区域（喇叭）被认为是与光学厚度小于5的PCTR模型拟合。在日珥边缘，Hα和Mg II的积分强度之间的理论关系得到了验证，并对应于低的发射测量值。在这些区域中的电子密度约为1010 cm-3，而在喇叭区域中的电子密度约为109 cm-3.结论在喇叭区域中，我们发现一些轮廓与高平均温度的模型拟合得最好.这表明，在角中发现的热PCTR可以被解释为在冕腔底部处于凝聚相的日珥等离子体。
ContextProminences are large magnetic structures in the corona filled by cool plasma with fast evolving fine structure.AimsWe aim to better understand the plasma conditions in the fine structure of a quiescent prominence including two transient horns observed at the bottom of the cavity using the high resolution Interface Region Imaging Spectrograph (IRIS) and the MulTi-Raies (MTR) spectrograph of the Télescope Heliographique pour l’Etude du Magnétisme et des Instabilités Solaires (THEMIS) in the Canary Islands.MethodsWe analysed the spectra obtained in Hαby THEMIS and Mg II by IRIS and compare them with a grid of 23 940 1D radiative transfer models which include a prominence-to-corona transition region (PCTR). The full observed profiles of Mg II in each pixel are fitted completely by synthesised profiles with ×RMS (Cross RMS; an improved version of the rolling root mean square (rRMS) method). When the RMS is below a certain threshold value, we recover the plasma conditions from the parameters of the model best fitting the observed line profile. This criterion is met in two regions (the horns and edge of the prominence) where the line profiles can generally be described as single peaked.ResultsThe 1D models suggest that two different kinds of model atmospheres correspond to these two regions. The region at the edge is found to be fitted mainly with isothermal and isobaric models, while the other area (the horns) is seen to be fitted with models with a PCTR that have optical thicknesses of less than 5. In the prominence edge, the theoretical relationship between the integrated intensities in Hαand Mg II is verified and corresponds to low emission measure values. In these regions the electron density is around 1010cm−3, while it is one order of magnitude less in the horn regions around 109cm−3.ConclusionsIn the horns, we find some profiles are best fitted with models with high mean temperatures. This suggests that the hot PCTR found in the horns could be interpreted as prominence plasma in condensation phase at the bottom of the coronal cavity.