Small-scale filament eruptions as the driver of X-ray jets in solar coronal holes
Small-scale filament eruptions as the driver of X-ray jets in solar coronal holes
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DOI：
10.1038/nature14556
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发表时间：
2015-07-23
期刊：
影响因子：
64.8
通讯作者：
Adams, Mitzi
中科院分区：
文献类型：
--
作者：
Sterling, Alphonse C.;Moore, Ronald L.;Adams, Mitzi
太阳 X 射线射流被认为是由射流底部的闭合磁场与周围的开放磁场突然重新连接而形成的(1,2)。在“新兴通量”模型的公认版本中，这种重新连接发生在开放场和新兴封闭场之间的等离子体电流片处，并且还形成通常在射流底部边缘观察到的局部 X 射线增亮 (1,3)。在这里，我们报告了对太阳两极日冕洞中形成的 20 个随机选择的 X 射线喷流的高分辨率 X 射线和极紫外观测结果。在每个喷流中，与新兴通量模型相反，启动日冕物质抛射（4-7）的细丝喷发的微型版本驱动了喷流产生的重新连接。 X射线亮点是通过重新连接携带微细丝的喷发封闭场的“腿”而出现的，类似于大规模喷发中太阳耀斑的形成。先前的观察发现，一些喷流是由基场喷发驱动的(8-11)，但只有一项这样的研究，只有一架喷流，暂时质疑了新兴通量模型(12)。我们的观察支持这样的观点，即太阳丝状喷发是由基本的爆炸性磁过程形成的，该过程发生在广泛的尺度上，从最大的质量抛射和耀斑喷发到 X 射线喷流，甚至可能到为日冕加热提供动力的较小喷流 (10,13,14)。之前曾提出过类似的情况，但这是根据不同的观察结果并基于喷发的微丝的不同来源推断出来的(15)。
Solar X-ray jets are thought to be made by a burst of reconnection of closed magnetic field at the base of a jet with ambient open field(1,2). In the accepted version of the 'emerging-flux' model, such a reconnection occurs at a plasma current sheet between the open field and the emerging closed field, and also forms a localized X-ray brightening that is usually observed at the edge of the jet's base(1,3). Here we report high-resolution X-ray and extreme-ultraviolet observations of 20 randomly selected X-ray jets that form in coronal holes at the Sun's poles. In each jet, contrary to the emerging-flux model, a miniature version of the filament eruptions that initiate coronal mass ejections(4-7) drives the jet-producing reconnection. The X-ray bright point occurs by reconnection of the 'legs' of the minifilament-carrying erupting closed field, analogous to the formation of solar flares in larger-scale eruptions. Previous observations have found that some jets are driven by base-field eruptions(8-11), but only one such study, of only one jet, provisionally questioned the emerging-flux model(12). Our observations support the view that solar filament eruptions are formed by a fundamental explosive magnetic process that occurs on a vast range of scales, from the biggest mass ejections and flare eruptions down to X-ray jets, and perhaps even down to smaller jets that may power coronal heating(10,13,14). A similar scenario has previously been suggested, but was inferred from different observations and based on a different origin of the erupting minifilament(15).