迈向太阳多谱线反演

中文摘要 AI 辅助

太阳大气受到许多在水平方向仅测量数十公里尺度的事件显著影响。这些事件既发生在宁静区也发生在活动区，并由磁流体动力学过程所决定。它们的起源往往位于太阳大气的最底层。为了增进对色球和日冕加热、太阳发电机及其活动周期的理解，或改进对空间天气事件的预测，我们必须增强对此类小尺度事件的理解。在这项工作中，我首先描述了校准具有极高空间分辨率的偏振光谱观测的过程，并为MOMFBD图像重建算法的数学证明构建了基础模块。在第二部分中，我描述了FISS-SP原型，该原型旨在充分利用1.6米望远镜的分辨率能力。该仪器被构建用于为偏振光谱数据的图像重建提供合适的数据。所得数据能够分辨至衍射极限的小尺度特征。对于空间高分辨率的太阳光谱，同时解释几条谱线仍然是常态。理论研究表明，同时解释多条太阳谱线可以大大提高对噪声的鲁棒性。利用FISS-SP的观测，我将这一理论思想推进为实用技术。凭借此技术，我能够反演得到局部太阳大气的连贯模型，分辨出水平尺寸约49公里以下的结构。最后，我利用这些新技术解释了对一个太阳黑子孔的观测。在最后这一部分，我描述并分析了此前无法通过偏振光谱分辨的小尺度结构。典型的黑子孔边界特征——即带有亮粒移入黑子孔的暗条纹——被识别为对流特征。

英文摘要

The Sun's atmosphere is significantly influenced by events that often measure only tens of kilometres in the horizontal direction. They happen in both quiet and active regions and are determined by magneto-hydro-dynamic processes. Their origins often lie in the lowest layers of the solar atmosphere. To improve the understanding of chromospheric and coronal heating, the solar dynamo and its activity cycle, or to improve the prediction of space weather events we must therefore enhance our understanding of such small-scale events. In this work I first describe the process of calibrating spectropolarimetric observations with very high spatial resolution and put together the building blocks for the mathematical proof the MOMFBD image reconstruction algorithm. In the second part I describe the FISS-SP prototype which is designed to fully exploit the resolution power of a 1.6m telescope. This instrument is built to provide suitable data for image reconstruction of spectropolarimetric data. The resulting data can resolve small-scale features down to the diffraction limit. The simultaneous interpretation of a few lines is still the norm for spatially highly resolved solar spectra. Theoretical works have shown that the simultaneous interpretation of multiple solar lines can greatly improve the robustness against noise. Using observations from FISS-SP I advance the theoretical idea into a practical technique. With this I can retrieve a coherent model of the local solar atmosphere, resolving structures down to a horizontal size of about 49~km. Finally, I use those new techniques to interpret an observation of a solar pore. In this last part I describe and analyse small-scale structures, which could not be spectropolarimetrically resolved before. Typical pore-boundary features - namely, dark striations with bright grains moving into the pore - are identified as convective features.

发表机构

• Georg-August-Universität Göttingen（哥廷根大学）
• Max-Planck-Institut für Sonnensystemforschung（马克斯·普朗克太阳系研究所）
• Technische Universität Braunschweig（布伦瑞克工业大学）

机构由 AI 辅助整理，请以论文原文为准。

补充信息

备注

PhD Thesis

DOI

10.53846/goediss-11983