The Structure and Cause of Sunspot Penumbrae Investigated Using High-Resolution Spectropolarimetry

本文研究了太阳黑子半影的结构及其成因。研究人员利用高空间分辨率、高光谱分辨率和来自太阳光球的光的全偏振状态的数据进行反演。这种反演使他们能够确定矢量磁场和成线区域的热力学状态。具体来说，研究人员比较和对比了两种反演技术：一种是允许多个磁性大气和非磁性模式大气对探测信号做出贡献；第二种方法是在模型大气中考虑速度场和磁场矢量的整体梯度。更成功的反演程序决定了哪个模型适用于解释半影观测。最后，研究人员回答了半影在太阳黑子演化过程中是如何、为什么以及何时形成的。这项研究的结果描绘了一幅更连贯的太阳黑子半影的物理图景，在这方面的知识以前是有限的，试图理解太阳的磁流体动力学现象（特别是与太阳黑子有关的现象）。

This research investigates the structure and cause of sunspot penumbra. The investigators use an inversion of data that couple high spatial resolution, high spectral resolution, and the full polarization state of light from the solar photosphere. This inversion allows them to determine the vector magnetic field and the thermodynamic state in the line-forming region. Specifically, investigators compare and contrast two inversion techniques: one that allows multiple magnetic atmospheres and non-magnetic model atmosphere to contribute to the detected signal; the second, a procedure that allows for bulk gradients in the velocity field and magnetic vector within the model atmosphere. The more successful inversion procedure dictates which model applies to interpreting penumbral observations. Finally, the investigators answer how, why and when penumbrae form in sunspot evolution. Results from the research paint a more coherent physical picture of sunspot penumbrae, where knowledge has previously been limited, to attempt understanding magnetohydrodynamic phenomena in the sun (especially associated with sunspots).