DISPERSAL OF G-BAND BRIGHT POINTS AT DIFFERENT LONGITUDINAL MAGNETIC FIELD STRENGTHS
DISPERSAL OF G-BAND BRIGHT POINTS AT DIFFERENT LONGITUDINAL MAGNETIC FIELD STRENGTHS
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DOI：
10.1088/0004-637x/810/2/88
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发表时间：
2015-09
期刊：
影响因子：
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通讯作者：
Yunfei Yang;K. Ji;Song Feng;H. Deng;Feng Wang;Jiaben Lin
中科院分区：
文献类型：
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作者：
Yunfei Yang;K. Ji;Song Feng;H. Deng;Feng Wang;Jiaben Lin
G波段亮点被认为是磁通量管的足点。本文的目的是研究GBP的扩散制度和相关的纵向磁场强度之间的关系。用日之出/太阳光学望远镜获得了两个不同磁化环境的高分辨率观测。每次观察同时记录G波段滤波图和窄带滤波成像仪（NFI）斯托克斯I和V图像。GBP被自动识别和跟踪，然后根据它们的纵向磁场强度被分为几组，这些纵向磁场强度是使用逐点方法从校准的NFI磁图中提取的。分别采用拉格朗日方法和扩散指数分布方法来探索各组GBP的扩散机制。结果表明，无论采用哪种方法，扩散指数和扩散系数都随纵向磁场强度的增加呈指数下降。根据拟合方程推导出的经验公式描述了这些关系。较强的元素倾向于比弱元素扩散得更慢，与周围介质的磁通量无关。这可能是因为较强元素的磁能与气体的动能相比是不可忽略的，因此流动不会那么容易地扰动它们。
G-band bright points (GBPs) are thought to be the foot-points of magnetic flux tubes. The aim of this paper is to investigate the relation between the diffusion regimes of GBPs and the associated longitudinal magnetic field strengths. Two high resolution observations of different magnetized environments were acquired with the Hinode/Solar Optical Telescope. Each observation was recorded simultaneously with G-band filtergrams and Narrow-band Filter Imager (NFI) Stokes I and V images. GBPs are identified and tracked automatically, and then categorized into several groups by their longitudinal magnetic field strengths, which are extracted from the calibrated NFI magnetograms using a point-by-point method. The Lagrangian approach and the distribution of diffusion indices approach are adopted separately to explore the diffusion regime of GBPs for each group. It is found that the values of diffusion index and diffusion coefficient both decrease exponentially with the increasing longitudinal magnetic field strengths whichever approach is used. The empirical formulas deduced from the fitting equations are proposed to describe these relations. Stronger elements tend to diffuse more slowly than weak elements, independently of the magnetic flux of the surrounding medium. This may be because the magnetic energy of stronger elements is not negligible compared with the kinetic energy of the gas, and therefore the flows cannot perturb them so easily.