Heating at the Remote Footpoints as a Brake on Jet Flows along Loops in the Solar Atmosphere
Heating at the Remote Footpoints as a Brake on Jet Flows along Loops in the Solar Atmosphere
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远程足点的加热作为太阳大气中环流喷射流的制动
DOI：
10.3847/1538-4357/ab96bd
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Hui Fu
中科院分区：
文献类型：
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作者：
Zhenghua Huang;Qingmin Zhang;Lidong Xia;Bo Li;Zhao Wu;Hui Fu
我们报告了太阳动力学天文台、界面区域成像摄谱仪和 1 m 新型真空太阳望远镜对太阳喷流沿日冕环传播的观测结果。射流的喷射物由多热成分组成，并以大于 100 km s−1 的速度传播。在 Hα 图像中，在具有紧凑圆形形状的冠状环的远程足点处发现了增亮。大气成像组件 (AIA) 94 Å 通带中远程增亮的发射峰值比喷气机底座中的发射峰值滞后 60 秒。远程足点的增亮被认为是由非热电子、MHD 波和/或射流的磁重联过程产生的传导前沿加热的结果。远程足点的加热导致增亮沿着环向喷气机底座延伸，这被认为是色球蒸发。这显然对喷射物起到了制动作用，当色球蒸发和喷射物在环顶点附近的位置相遇时，导致 1.5 至 3 km s−2 范围内的减速，误差为 ∼1.0 km s−2 。这种射流的动力学提供了一个独特的机会来诊断远程足点的色球蒸发，从中我们推断出速度在 330–880 km s−1 范围内。
We report on observations of a solar jet propagating along coronal loops taken by the Solar Dynamics Observatory, the Interface Region Imaging Spectrograph, and the 1 m New Vacuum Solar Telescope. The ejecta of the jet consist of multithermal components and propagate with a speed greater than 100 km s−1. Brightenings are found in the remote footpoints of the coronal loops having compact and round shape in the Hα images. The emission peak of the remote brightening in the Atmospheric Imaging Assembly (AIA) 94 Å passband lags 60 s behind that in the jet base. The brightenings in the remote footpoints are believed to be consequences of heating by nonthermal electrons, MHD waves, and/or a conduction front generated by the magnetic reconnection processes of the jet. The heating in the remote footpoints leads to extension of the brightening along the loops toward the jet base, which is believed to be the chromospheric evaporation. This apparently acts as a brake on the ejecta, leading to a deceleration in the range from 1.5 to 3 km s−2 with an error of ∼1.0 km s−2 when the chromospheric evaporation and the ejecta meet at locations near the loop apexes. The dynamics of this jet allows for a unique opportunity to diagnose the chromospheric evaporation from the remote footpoints, from which we deduce a velocity in the range of 330–880 km s−1.