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arXiv 1802.07965astro-ph.SR
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日冕中形成的通量绳的观测约束模型

An Observationally-Constrained Model of a Flux Rope that Formed in the Solar Corona

Alexander W. James, Gherardo Valori, Lucie M. Green, Yang Liu, Mark C. M. Cheung, Yang Guo, Lidia van Driel-Gesztelyi

摘要:

日冕物质抛射(CME)是恒星日冕等离子体的大规模喷发。了解日冕物质抛射引发的等离子体过程可应用于空间天气预报和实验室等离子体实验。James等人(Sol. 292,71,2017)使用EUV观测得出结论,在2012年6月14日爆发之前,NOAA活动区11504上方的日冕中形成了磁通量绳(SOL 2012 -06-14)。在这项工作中,我们使用的数据从太阳动力学天文台模拟的活动区的日冕磁场喷发前一个小时,使用非线性无力场外推,并找到一个通量绳达到最大高度150 Mm以上的光球。估计的平均扭曲的强烈不对称的外推磁通绳是1.35和1.88圈之间,这取决于轴的选择,虽然喷发的结构没有观察到扭结。外推通量绳的轴的顶点附近的衰变指数是典型的临界值所需的发病环面不稳定,所以我们建议,环面不稳定驱动的喷发。

英文摘要:

Coronal mass ejections (CMEs) are large-scale eruptions of plasma from the coronae of stars. Understanding the plasma processes involved in CME initiation has applications to space weather forecasting and laboratory plasma experiments. James et al. (Sol. Phys. 292, 71, 2017) used EUV observations to conclude that a magnetic flux rope formed in the solar corona above NOAA Active Region 11504 before it erupted on 14 June 2012 (SOL2012-06-14). In this work, we use data from the Solar Dynamics Observatory to model the coronal magnetic field of the active region one hour prior to eruption using a nonlinear force-free field extrapolation, and find a flux rope reaching a maximum height of 150 Mm above the photosphere. Estimations of the average twist of the strongly asymmetric extrapolated flux rope are between 1.35 and 1.88 turns, depending on the choice of axis, although the erupting structure was not observed to kink. The decay index near the apex of the axis of the extrapolated flux rope is comparable to typical critical values required for the onset of the torus instability, so we suggest that the torus instability drove the eruption.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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