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arXiv 1703.08992astro-ph.SR
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由磁通量绳喷发引起的太阳爆发喷流

A solar blowout jet caused by the eruption of a magnetic flux rope

Xiaoshuai Zhu, Huaning Wang, Xin Cheng, Chong Huang

摘要:

利用新近开发的强迫场外推(FFE)模型,研究了2012年7月2日起源于NOAA活动区(AR)11513西缘的一个喷流的三维(3D)磁结构。结果表明,喷流是由扭曲磁力线组成的磁通量绳(MFR)喷发引起的。我们进一步计算了重建磁场的扭曲数$\mathcal{T}_{w}$和压缩因子Q,发现(1)MFR与高$\mathcal{T}_{w}$区很好地对应,(2)MFR外边界与高Q区很好地对应,可能解释了喷流底部的明亮结构。MFR的捻数估计为$\mathcal{T}_{w}=-1.54\pm 0.67$。因此,当$\mathcal{T}_{w}$达到甚至超过扭结不稳定性阈值时,扭结不稳定性被认为是井喷射流的启动机制。我们的研究结果还表明,在衰减阶段的亮点实际上是由一些小的环路,这些环路被上面发生的重联加热。总之,井喷射流是大多数情况下与\citet{mcs10}提出的方案一致,除了扭结不稳定被认为是一个可能的触发器。

英文摘要:

We investigate the three-dimensional (3D) magnetic structure of a blowout jet originated in the west edge of NOAA Active Region (AR) 11513 on 02 July 2012 by means of recently developed forced field extrapolation (FFE) model. The results show that the blowout jet was caused by the eruption of the magnetic flux rope (MFR) consisting of twisted field lines. We further calculate the twist number $\mathcal{T}_{w}$ and squashing factor Q of the reconstructed magnetic field and find that (1) the MFR corresponds well to the high $\mathcal{T}_{w}$ region (2) the MFR outer boundary corresponds well to the high Q region, probably interpreting the bright structure at the base of the jet. The twist number of the MFR is estimated to be $\mathcal{T}_{w}=-1.54\pm 0.67$. Thus, the kink instability is regarded as the initiation mechanism of the blowout jet as $\mathcal{T}_{w}$ reaching or even exceeding the threshold value of the kink instability. Our results also indicate that the bright point at the decaying phase is actually comprised of some small loops that are heated by the reconnection occurred above. In summary, the blowout jet is mostly consistent with the scenario proposed by \citet{mcs10} except that the kink instability is found to be a possible trigger.

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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