Formation and thermodynamic evolution of plasmoids in active region jets
Formation and thermodynamic evolution of plasmoids in active region jets
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活动区喷流中等离子体团的形成和热力学演化
DOI：
10.1093/mnras/stac3035
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发表时间：
2023
影响因子：
4.8
通讯作者：
Mulay S
中科院分区：
文献类型：
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作者：
Mulay S
我们已经进行了全面的研究等离子体团的温度结构，连续发生在经常性的活动区喷流。在大气成像组件（AIA）记录的EUV/UV图像中，可以看到多热等离子体团沿着多螺纹螺旋以及在足点区域行进。差分发射测量（DEM）分析使用EUV AIA图像，并结合X射线望远镜（XRT/Hinode）的X射线图像约束DEM的高温部分。我们观察到一个系统的上升和下降的亮度，电子数密度和峰值温度的螺旋等离子体团在其传播沿着射流。发现足点处的等离子体团（FP）（1.0-2.5 MK）和尖顶处的等离子体团（SP）（1.0-2.24 MK）具有相似的峰值温度，而FP具有比SP（1.3-3.0 MK）更高的DEM加权温度（2.2-5.7 MK）。等离子体团的电子数密度下限在3.4-6.1 × 108 cm− 3之间，而螺旋体的电子数密度下限在2.6-3.2 × 108 cm −3之间。我们的分析表明，这些等离子体团的发射开始接近射流的底部，我们认为在那里形成了强电流界面。这表明，斑点是由撕裂模式不稳定性引起的等离子体团。
We have carried out a comprehensive study of the temperature structure of plasmoids, which successively occurred in recurrent active region jets. The multithermal plasmoids were seen to be travelling along the multithreaded spire as well as at the footpoint region in the EUV/UV images recorded by the Atmospheric Imaging Assembly (AIA). The differential emission measure (DEM) analysis was performed using EUV AIA images, and the high-temperature part of the DEM was constrained by combining X-ray images from the X-ray telescope (XRT/Hinode). We observed a systematic rise and fall in brightness, electron number densities and the peak temperatures of the spire plasmoid during its propagation along the jet. The plasmoids at the footpoint (FPs) (1.0–2.5 MK) and plasmoids at the spire (SPs) (1.0–2.24 MK) were found to have similar peak temperatures, whereas the FPs have higher DEM weighted temperatures (2.2–5.7 MK) than the SPs (1.3–3.0 MK). A lower limit to the electron number densities of plasmoids – SPs (FPs) were obtained that ranged between 3.4–6.1 × 108(3.3–5.9 × 108) cm−3whereas for the spire, it ranged from 2.6–3.2 × 108cm−3. Our analysis shows that the emission of these plasmoids starts close to the base of the jet(s), where we believe that a strong current interface is formed. This suggests that the blobs are plasmoids induced by a tearing-mode instability.