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arXiv 0912.2637astro-ph.SR
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由Hinode/SOT观测得到的磁亮点的大小分布

The size distribution of magnetic bright points derived from Hinode/SOT observations

D. Utz, A. Hanslmeier, C. Möstl, R. Muller, A. Veronig, H. Muthsam

摘要:

上下文磁亮点(Magnetic Bright Points,MBPs)是太阳光球层中的小尺度磁特征。它们可能是日冕加热的一个可能来源,通过快速的足点运动引起磁流体动力波。粒子的数量和尺寸分布对小尺度磁场能量的估算至关重要。目标。由Hinode/SOT仪器获得的G-波段图像的MBPs的尺寸分布。方法.为了识别的目的,开发了一种新的自动分割和识别算法。结果对于0.108弧秒/像素的采样,我们推导出的MBPs的平均直径为(218 +- 48)公里。对于采样为0.054弧秒/像素的全分辨数据集,大小分布移动到平均直径(166 +- 31)公里。所确定的直径与早期公布的值一致。这种变化很可能是由于不同的空间采样。结论.我们的结论是,最小的磁性元素在太阳光球层还不能解决G波段的观测。离散化效应(抽样)的影响也尚未得到充分的研究。

英文摘要:

Context. Magnetic Bright Points (MBPs) are small-scale magnetic features in the solar photosphere. They may be a possible source of coronal heating by rapid footpoint motions that cause magnetohydrodynamical waves. The number and size distribution are of vital importance in estimating the small scale-magnetic-field energy. Aims. The size distribution of MBPs is derived for G-band images acquired by the Hinode/SOT instrument. Methods. For identification purposes, a new automated segmentation and identification algorithm was developed. Results. For a sampling of 0.108 arcsec/pixel, we derived a mean diameter of (218 +- 48) km for the MBPs. For the full resolved data set with a sampling of 0.054 arcsec/pixel, the size distribution shifted to a mean diameter of (166 +- 31) km. The determined diameters are consistent with earlier published values. The shift is most probably due to the different spatial sampling. Conclusions. We conclude that the smallest magnetic elements in the solar photosphere cannot yet be resolved by G-band observations. The influence of discretisation effects (sampling) has also not yet been investigated sufficiently.

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。

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