论文标题
较低太阳大气中无处不在的磁重新连接事件的特性
Properties of ubiquitous magnetic reconnection events in the lower solar atmosphere
论文作者
论文摘要
深太阳大气中的磁重新连接会导致Balmer氢管的发射增强，这一现象称为Ellerman炸弹。最近的高质量H $β$观察结果表明，Ellerman炸弹比以前认为的更为普遍，据估计，在安静的太阳中，任何时候都有大约半百万埃尔曼炸弹。在这些新的H $β$观测值中，我们对安静的Sun Ellerman炸弹（QSEB）进行了广泛的统计表征。我们分析了用瑞典1-m太阳能望远镜观察到的1小时的安静太阳数据集，该数据集由H $β$和H $α$线中的光谱成像以及Fe I 617.3 nm中的光谱极化成像组成。我们总共检测到2809个QSEB。寿命在9 s至20.5分钟之间变化，中位数为1.14分钟。最大面积在0.0016至0.2603毫米$^2 $之间，中位数为0.018毫米$^2 $。 QSEB的子集（14％）显示了H $β$线核的增强。平均而言，在机翼亮亮开始后，线核亮度出现0.88分钟，这些亮丽之间的距离为243 km。这引起了明显的传播速度，范围在$ -14.3至+23.5 km s $^{ - 1} $之间，平均值向上传播为+4.4 km $^{ - 1} $。平均方向几乎平行于肢体方向。 QSEB几乎均匀地分布在视野上，但我们发现具有中句大小的空区域。 QSEB位于磁网络附近更频繁的地方，它们通常更大，寿命更长且更明亮。我们得出的结论是，QSEB无处不在，在宁静的阳光下，除了最弱的磁场的中间区域（$ b _ {\ rm {los}} \ Lessim 50 $ 〜g）外，出现在任何地方。我们的观察结果支持沿垂直扩展的电流板的重新连接的解释。
Magnetic reconnection in the deep solar atmosphere can give rise to enhanced emission in the Balmer hydrogen lines, a phenomenon referred to as Ellerman bombs. Recent high quality H$β$ observations indicate that Ellerman bombs are more common than previously thought and it was estimated that at any time about half a million Ellerman bombs are present in the quiet Sun. We performed an extensive statistical characterization of the quiet Sun Ellerman bombs (QSEBs) in these new H$β$ observations. We analyzed a 1 h dataset of quiet Sun observed with the Swedish 1-m Solar Telescope that consists of spectral imaging in the H$β$ and H$α$ lines, as well as spectropolarimetric imaging in Fe I 617.3 nm. We detected a total of 2809 QSEBs. The lifetime varies between 9 s and 20.5 min with a median of 1.14 min. The maximum area ranges between 0.0016 and 0.2603 Mm$^2$ with a median of 0.018 Mm$^2$. A subset (14%) of the QSEBs display enhancement of the H$β$ line core. On average, the line core brightening appears 0.88 min after the onset of brightening in the wings, and the distance between these brightenings is 243 km. This gives rise to an apparent propagation speed ranging between $-$14.3 and +23.5 km s$^{-1}$, with an average that is upward propagating at +4.4 km $^{-1}$. The average orientation is nearly parallel to the limbward direction. QSEBs are nearly uniformly distributed over the field of view but we find empty areas with the size of mesogranulation. QSEBs are located more frequent near the magnetic network where they are often bigger, longer lived and brighter. We conclude that QSEBs are ubiquitous in quiet Sun and appear everywhere except in areas of mesogranular size with weakest magnetic field ($B_{\rm{LOS}}\lesssim50$~G). Our observations support the interpretation of reconnection along vertically extended current sheets.
