本影点及其亚结构的形态和演化
Morphology and evolution of umbral dots and their substructures
摘要：
通过对磁对流的数值模拟，预测了本影点的暗带和拖尾等亚结构。我们分析了一个6小时23分钟的时间序列的宽带图像的一个大的本影在活动区域NOAA 10634，1米瑞典太阳望远镜，在602 nm左右的波长带收购。该系列的43分钟部分用MFBD方法重建，达到0.14”的空间分辨率。我们测量亮度，大小，寿命和水平速度的各种阴影结构。大多数（90%）的UD和微弱LB中的亮点状特征分裂和合并，它们的中位寿命为3.5或5.7分钟，这取决于分裂或合并事件是否被认为是它们寿命的结束。不分裂或合并的模糊LB中的UD和特征两者都明显小于（0.15”）所有特征的平均大小（0.17”）。本影明亮的小尺度特征的水平运动要么指向本影，要么沿着平均水平速度为0.34公里/秒的微弱LB。速度超过0.4 km/s的特征主要出现在本影的外围。在四个明亮的中央UD（CUD）中测量的暗泳道的强度比CUD的峰值强度低0.8倍。暗泳道的宽度可能小于分辨率限值0.14”。UDs亚结构变化的特征时间约为4 min。我们观察到与PUDs相连的窄（0.14”）亮暗丝。通常，一条深色和两条明亮的细丝形成0.4”宽的尾巴，附着在一个PUD上，类似于短的深色核心半影细丝。我们的研究结果表明，位于明亮半影丝尖端的PUD和PG之间的相似性。在数值MHD模拟中看到的功能是一致的，我们的观察暗线CUDs和尾巴连接到PUDs。
英文摘要：
Substructures - dark lanes and tails - of umbral dots (UDs) were predicted by numerical simulations of magnetoconvection. We analyse a 6 h 23 min time series of broadband images of a large umbra in the active region NOAA 10634, acquired with the 1-m Swedish Solar Telescope, in the wavelength band around 602 nm. A 43 min part of this series was reconstructed with the MFBD method, reaching a spatial resolution of 0.14". We measure brightness, size, lifetime, and horizontal velocities of various umbral structures. Most (90 %) of UDs and bright point-like features in faint LBs split and merge, and their median lifetimes are 3.5 or 5.7 min, depending on whether the split or merge event is considered as the end of their life. Both UDs and features in faint LBs that do not split or merge are clearly smaller (0.15") than the average size (0.17") of all features. Horizontal motions of umbral bright small-scale features are directed either into the umbra or along faint LBs with mean horizontal velocities of 0.34 km/s. Features faster than 0.4 km/s appear mostly at the periphery of the umbra. The intensity of dark lanes, measured in four bright central UDs (CUDs), is by a factor 0.8 lower than the peak intensity of CUDs. The width of dark lanes is probably less than the resolution limit 0.14". The characteristic time of substructure changes of UDs is ~4 min. We observe narrow (0.14") bright and dark filaments connected with PUDs. Usually one dark and two bright filaments form a 0.4" wide tail attached to one PUD, resembling a short dark-cored penumbral filament. Our results indicate the similarity between PUDs and PGs located at the tips of bright penumbral filaments. The features seen in numerical MHD simulations are consistent with our observations of dark lanes in CUDs and tails attached to PUDs.
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。
