Capturing transient plasma flows and jets in the solar corona
Capturing transient plasma flows and jets in the solar corona
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DOI：
10.1051/0004-6361/202141683
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发表时间：
2021-12-14
影响因子：
6.5
通讯作者：
Verbeeck, C.
中科院分区：
文献类型：
--
作者：
Chitta, L. P.;Solanki, S. K.;Verbeeck, C.
紫外线(UV)至X射线波长的强度爆发和等离子体喷流是磁场重联和与之相关的太阳大气等离子体脉冲加热的典型标志。为了获得对这一过程的新见解，需要进行高频率的观测，以捕捉等离子体对磁重联的快速响应以及喷流的高度动态演化。在这里，我们报告了由太阳轨道飞行器上的极紫外成像仪的174埃高分辨率成像仪记录的第一批2个S韵律的极端紫外线观测。这些观测覆盖了宁静的太阳冕区，揭示了作为局域加热事件的磁重联的开始特征。然后，这些局部来源显示出反复的等离子喷发或喷流活动。我们的观测表明，这种从局域源到喷流活动的空间形态变化可以在约20 S的时间尺度上迅速发生。喷流本身是间歇的，并且是在约20 S的时间尺度上从震源区产生的。在这些事件的初始阶段，根据传播强度扰动的推断，等离子体喷流的速度在100公里S(-1)到150公里S(-1)的范围内。然后，这些喷流传播到大约5毫米的长度。我们讨论了观察到的双向和单向喷流活动的例子，这些活动是从日冕中最初的局部爆发开始的。日冕爆发和相关的等离子体流动或喷流的瞬变性质及其动力学可以为日冕爆发和喷流的磁重联模型提供基准。
Intensity bursts in ultraviolet (UV) to X-ray wavelengths and plasma jets are typical signatures of magnetic reconnection and the associated impulsive heating of the solar atmospheric plasma. To gain new insights into the process, high-cadence observations are required to capture the rapid response of plasma to magnetic reconnection as well as the highly dynamic evolution of jets. Here, we report the first 2 s cadence extreme-UV observations recorded by the 174 angstrom High Resolution Imager of the Extreme Ultraviolet Imager on board the Solar Orbiter mission. These observations, covering a quiet-Sun coronal region, reveal the onset signatures of magnetic reconnection as localized heating events. These localized sources then exhibit repeated plasma eruptions or jet activity. Our observations show that this spatial morphological change from localized sources to jet activity could occur rapidly on timescales of about 20 s. The jets themselves are intermittent and are produced from the source region on timescales of about 20 s. In the initial phases of these events, plasma jets are observed to exhibit speeds, as inferred from propagating intensity disturbances, in the range of 100 km s(-1) to 150 km s(-1). These jets then propagate to lengths of about 5 Mm. We discuss examples of bidirectional and unidirectional jet activity observed to have been initiated from the initially localized bursts in the corona. The transient nature of coronal bursts and the associated plasma flows or jets along with their dynamics could provide a benchmark for magnetic reconnection models of coronal bursts and jets.