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arXiv 1705.03040astro-ph.SR
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太阳活动区日冕急流II:剧烈急流的触发和演化

Solar Active Region Coronal Jets II: Triggering and Evolution of Violent Jets

Alphonse C. Sterling, Ronald L. Moore, David A. Falconer, Navdeep K. Panesar, Francisco Martinez

摘要:

利用Hinode/XRT、SDO/AIA和HMI以及IRIS数据,我们研究了AR 12259黑子外一系列X射线明亮、快速演化的活动区日冕喷流。在我们之前对活跃区域喷流的研究之后,这种快速演变的“暴力”喷流的详细演变仍然是一个谜(Sterling et al. 2016,Paper 1)。我们研究的喷流从三个局部分区喷发,每个分区都包含一个快速演化的(正)少数极性磁通补丁,沐浴在(多数)负极性磁通背景中。至少有几个喷流开始于似乎是薄(厚度<~2”)的微型细丝(minifilament)“股”从磁中性线的喷发,其中磁通量抵消正在进行,与Sterling等人(2015)提出的日冕洞喷流的磁性配置一致。一些喷流束很难/不可能被检测到,可能是由于例如它们的薄度、被周围明亮或黑暗的特征所遮蔽,或者在那些喷流中没有喷发的冷物质微丝。详细跟踪的通量演变的一个分区,我们发现爆发的强射流只发生在强通量取消的时候。在7次喷射事件中,平均抵消率约为1.5 × 10^19 Mx/hr,每次喷射事件前平均抵消的磁通量约为5 × 10^18 Mx,可以说每次喷射会产生约10^28 - 10^29尔格的自由磁能。从这些和以前的观察,我们推断,通量抵消是负责喷发前的建设和触发至少有许多喷流在活跃地区,安静的地区,和冕洞的基本过程。

英文摘要:

We study a series of X-ray-bright, rapidly-evolving active-region coronal jets outside the leading sunspot of AR 12259, using Hinode/XRT, SDO/AIA and HMI, and IRIS data. The detailed evolution of such rapidly evolving "violent" jets remained a mystery after our previous investigation of active region jets (Sterling et al. 2016, Paper 1). The jets we investigate here erupt from three localized subregions, each containing a rapidly evolving (positive) minority-polarity magnetic-flux patch bathed in a (majority) negative-polarity magnetic-flux background. At least several of the jets begin with eruptions of what appear to be thin (thickness <~2") miniature-filament (minifilament) "strands" from a magnetic neutral line where magnetic flux cancelation is ongoing, consistent with the magnetic configuration presented for coronal-hole jets in Sterling et al. (2015). Some jets strands are difficult/impossible to detect, perhaps due to, e.g. their thinness, obscuration by surrounding bright or dark features, or the absence of erupting cool-material minifilaments in those jets. Tracing in detail the flux evolution in one of the subregions, we find bursts of strong jetting occurring only during times of strong flux cancelation. Averaged over seven jetting episodes, the cancelation rate was ~1.5x10^19 Mx/hr. An average flux of ~5x10^18 Mx canceled prior to each episode, arguably building up ~10^28 - 10^29 ergs of free magnetic energy per jet. From these and previous observations, we infer that flux cancelation is the fundamental process responsible for the pre-eruption buildup and triggering of at least many jets in active regions, quiet regions, and coronal holes.

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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