High-resolution imaging of solar pores
High-resolution imaging of solar pores
复制标题
太阳孔隙的高分辨率成像
DOI：
10.1051/0004-6361/202245410
复制
发表时间：
2023
影响因子：
6.5
通讯作者：
Wang, H.
中科院分区：
文献类型：
--
作者：
Kamlah, R.;Verma, M.;Denker, C.;Wang, H.
光桥是明亮、长、窄的特征，通常与太阳黑子和孔隙的形成或衰变过程有关。目的研究磁场与等离子体流动的相互作用，在一个活动区域的尾部，在那里孔隙和磁结演变成一个复杂的太阳黑子。目标是识别光球和色球过程，这些过程将孔隙的主要垂直磁场转化为具有多个本影核，光桥和原始半影的太阳黑子。方法利用各种望远镜和仪器进行观测，可以了解不同的大气层以及与强磁场有关的特征形态的变化。太阳动力学观测台（SDO）的日震和磁成像仪（HMI）提供了全盘连续图像和视线磁图，而大熊太阳观测台（BBSO）的goosolar望远镜（GST）提供的各种波长的高分辨率观测数据可以推断出孔隙周围的精细结构和流动。水平固有运动是利用局部相关跟踪（LCT）对可用时间序列进行评估，而太阳黑子特征的连通性可以利用背景减去活动图（BaSAMs）来建立。结果：光球流图显示径向流出，其中光桥连接到周围的颗粒，而流入存在于孔隙的边界。相比之下，色球流图显示在超半影尺度强烈的径向流出，即使在光球中没有半影。两个极性之间的区域的特点是膨胀的颗粒产生强大的散度中心。basam的变化是随着毛孔内部和周围的显著和持续变化的位置而变化的。由此得到的图显示了沿着轻桥的低变化，以及连接轻桥和孔隙的细发际线，以及孔隙边界的强变化。各种basam显示了孔隙与周围超颗粒细胞的相互作用。h α视距速度图提供了对流体结构的进一步了解，显示了孔隙周围一些径向细丝的扭曲运动。此外，在视距速度图中还可以看到连接活跃区两极的细丝上的流动。结论等离子体运动在孔隙内部和周围的微小变化都有利于孔隙向太阳黑子的转化。此外，半影丝的色球对应体在光球中出现的时间要比半影丝早得多。半影的形成得益于稳定的磁性特征，它锚定了磁通量的平流，并提供了与周围超颗粒细胞的连接，而不断出现的磁通量和强光桥是影响太阳黑子及其半影的外观和复杂性的反作用力。
ContextLight bridges are bright, long, and narrow features that are typically connected to the formation or decay processes of sunspots and pores.AimsThe interaction of magnetic fields and plasma flows is investigated in the trailing part of an active region, where pores and magnetic knots evolve into a complex sunspot. The goal is to identify the photospheric and chromospheric processes, which transform the mainly vertical magnetic fields of pores into a sunspot with multiple umbral cores, light bridges, and rudimentary penumbrae.MethodsConducting observations with a broad variety of telescopes and instruments provides access to different atmospheric layers and the changing morphology of features connected to strong magnetic fields. While the Helioseismic and Magnetic Imager (HMI) of the Solar Dynamics Observatory (SDO) provides full-disk continuum images and line-of-sight magnetograms, the fine structure and flows around a pore can be deduced from high-resolution observations in various wavelengths as provided by theGoodeSolar Telescope (GST) at the Big Bear Solar Observatory (BBSO). Horizontal proper motions are evaluated applying local correlation tracking (LCT) to the available time series, whereas the connectivity of sunspot features can be established using the background-subtracted activity maps (BaSAMs).ResultsPhotospheric flow maps indicate radial outflows, where the light bridge connects to the surrounding granulation, whereas inflows are present at the border of the pores. In contrast, the chromospheric flow maps show strong radial outflows at superpenumbral scales, even in the absence of a penumbra in the photosphere. The region in between the two polarities is characterized by expanding granules creating strong divergence centers. Variations in BaSAMs follow locations of significant and persistent changes in and around pores. The resulting maps indicate low variations along the light bridge, as well as thin hairlines connecting the light bridge to the pores and strong variations at the border of pores. Various BaSAMs demonstrate the interaction of pores with the surrounding supergranular cell. The Hαline-of-sight velocity maps provide further insights into the flow structure, with twisted motions along some of the radial filaments around the pore with the light bridge. Furthermore, flows along filaments connecting the two polarities of the active region are pronounced in the line-of-sight velocity maps.ConclusionsThe present observations reveal that even small-scale changes of plasma motions in and around pores are conducive to transform pores into sunspots. In addition, chromospheric counterparts of penumbral filaments appear much earlier than the penumbral filaments in the photosphere. Penumbra formation is aided by a stable magnetic feature that anchors the advection of magnetic flux and provides a connection to the surrounding supergranular cell, whereas continuously emerging flux and strong light bridges are counteragents that affect the appearance and complexity of sunspots and their penumbrae.