KMS of Xinjiang Astronomical Observatory, CAS
| 太阳日冕加热的高分辨率观测研究 | |
| Alternative Title | Study of solar coronal heating with high resolution observations |
帕力旦木·阿西木
| |
| Subtype | 博士 |
| Thesis Advisor | 王娜 |
| 2020-08-01 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Name | 理学博士 |
| Degree Discipline | 天体物理 |
| Keyword | 太阳大气 太阳磁场 太阳日冕 |
| Abstract | 太阳日冕的温度高达百万度，如此高的温度是如何产生和维持的？给日冕物质持续提供能量的物理机制又是什么？这是当代天体物理领域的一个还没得到解决的难题。目前有关日冕加热的观测研究虽然取得了令人振奋的研究结果，但这些研究大多缺乏低层大气的观测，因此难以追踪能量从光球、色球向日冕输运的完整过程。本论文从低层大气的观测出发，主要分析了远紫外moss区域的低层大气结构与日冕加热的关系。 本论文中，我们利用了高分辨率的SDO/AIA和SDO/HMI空间望远镜的多波段观测数据以及BBSO/GST的高分辨率资料，主要针对太阳谱斑区域视向磁场的时间分布的准周期扰动进行了广泛的研究。在本论文的第一章中我们给出了关于太阳大气和太阳日冕加热机制的简要介绍。第二章介绍了多波段观测仪器，主要是SDO/AIA 、SDO/HMI 、IRIS 等空间探测器和地面仪器BBSO/GST。第三章和第四章分别介绍了我们利用SDO成像观测和GST高分辨率观测所做的主要工作。第五章中给出了我们的工作总结和未来的研究方向。 在第三章中，我们对于2011年7月22的活动区NOAA 11259谱斑视向(LOS)磁场的时间分布的准周期扰动进行了研究。我们发现这些扰动与He I 10830Å吸收的增强有关，由于He I 10830Å 吸收的增强，通常意味着EUV辐射的增亮。因而这是磁场扰动和日冕加热相关的初步迹象。对扰动的FFT分析给出了一种类似于多普勒速度的频谱：大约5分钟的一些离散周期。它们的振幅与磁场强度成正比，相位比P模多普勒速度滞后四分之一个周期。我们用高β等离子体中的MHD磁声振荡的一个解很好的解释了上述观测现象。观测分析还表明，磁扰动以驻波的形式存在。对于磁场较强和较弱的两个区域，扰动总是反相位的。由p模振荡驱动的，以上所有的结果都表明，我们观测到的磁扰动实际上是太阳表面即光球上的磁声波振荡。这一发现为探索磁声波振荡与太阳高层大气加热的关系及其在太阳日震学中的作用提供了新的诊断工具。 在第四章中，在第三章的工作基础之上，我们进一步研究了紫外(EUV)辐射与同样一个EUV moss区域磁声振荡之间的关系。所利用的资料是对太阳大气层中的三个层次分别进行的高分辨率观测，包括光球层的Tio 7057Å 处的高分辨率宽带成像和视向磁图、色球层的He I 10830Å 高分辨率窄带像以及过渡区171Å 处的EUV像。目的是解决来自光球层，穿过色球层并最终加热太阳过渡区或日冕的精细物质和能量流。通过数据分析，我们总结出了以下新的现象：1) 表现为10830Å 吸收的重复性注入的色球物质从米粒间通道中喷出，周期大约为 5 分钟。2)EUV 辐射被发现是周期性的，具有相似的 ~ 5分钟周期。3)在10830Å 吸收增强的注入区周围，EUV辐射和磁场强度都显著增强。4)EUV辐射时间轮廓上的峰值与该区域强磁场的振荡峰值是同步的。综上所述，我们发现极紫外(EUV)辐射与EUV moss区磁声振荡之间存在良好的相关性。这一发现为磁声波驱动的日冕加热提供了有力的证据。 |
| Other Abstract | The temperature of the sun's corona is as high as one million degrees. How is such a high temperature generated and maintained? What is the physical mechanism for the continuous energy supply of coronal matter? This is an unsolved problem in the field of contemporary astrophysics. Although some exciting results have been obtained in the study of coronal heating, most of them lack the observation of lower atmosphere, so it is difficult to trace the whole process of energy transport from photosphere and chromosphere to corona. In this thesis,we analyze the relationship between the structure of the lower atmosphere and the coronal heating based on high-resolution observations of the lower atmosphere . In this thesis, we used the multi-wavelength observation data of high-resolution SDO/AIA and SDO/HMI space telescopes as well as the BBSO/GST high-resolution data to study the quasi periodic disturbance of the temporal distribution of the line of sight magnetic field in the solar plage area. In the first chapter of this thesis, we give a brief introduction on the solar atmosphere and the solar corona heating mechanism. The second chapter introduces multi-wavelength observation instruments, mainly SDO/AIA 、SDO/HMI 、IRIS space detectors and ground instruments BBSO/GST. Chapter 3 and Chapter 4 introduce our main works in which SDO imaging observations and GST high-resolution observations are used, respectively. chapter 5 gives a summary of our work and future research directions. In chapter 3,we investigate the quasi periodic disturbance of the time distribution of the line of sight (LOS) magnetic field in the active region of NOAA 11259 on July 22, 2011. The perturbations are found to be associated with enhancement of He I 10830 Å absorption, which usually signifies brightening of EUV emission. FFT analysis to the perturbations gives a kind of spectra similar to that of Doppler velocity: a number of discrete periods around 5 minutes. Their amplitudes are found to be proportional to magnetic field strength and their phases are a quarter of cycle ahead of the p-mode Doppler velocity. We show that the relationships can be well explained with an MHD solution for the magneto-acoustic oscillations in high-β plasma. Observational analysis also shows that the magnetic perturbations are in the form of standing waves: for the two regions with the stronger and weaker magnetic field, the perturbations are always anti-phased. Our results show that the magnetic perturbations are actually magneto- acoustic oscillations on the solar surface, the photosphere, powered by p-mode oscillations. The findings in our works may provide a new diagnostic tool for exploring the relationship between magneto-acoustic oscillations and the heating of solar upper atmosphere, as well as their role in helioseismology. In chapter 4, In order to further explore the relationship between EUV emission and Magneto-acoustic oscillation in EUV moss region, high-resolution observations of three atmospheric levels on the Sun were carried out.The observations consist of high-resolution broad-band imaging at TiO 7057 Å and line of sight magnetograms for the photosphere, high-resolution narrow-band images at Helium I 10830 Å for the chromosphere and EUV images at 171 Å for the transition region. The analysis area is the active region plage NOAA 11259,The result is obtained from a detailed multi-wavelength data analysis to the region with the purpose of resolving fine-scale mass and energy flows that come from the photosphere, pass through the chromosphere and finally heat solar transition region or the corona. We report following new phenomena: 1) Repeated injections of chromospheric material shown as 10830 Å absorption are squirted out from inter-granular lanes with the period of ~ 5 minutes. 2) EUV emissions are found to be periodically modulated with the similar periods of ~ 5 minutes. 3) Around the injection area where 10830 Å absorption is enhanced, both EUV emissions and the strength of magnetic field are remarkably stronger. 4) The peaks on the time profile of the EUV emissions are found to be in sync with oscillatory peaks of the stronger magnetic field in the region. There is a nice correlation between extreme-violet (EUV) emission and magneto-acoustic oscillations in a EUV moss region.These findings may give a series of strong evidences supporting the scenario of coronal heating powered by magneto-acoustic waves。 |
| Pages | 104 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/4733 |
| Collection | 研究生学位论文 |
| Recommended Citation GB/T 7714 | 帕力旦木·阿西木. 太阳日冕加热的高分辨率观测研究[D]. 北京. 中国科学院大学,2020. |
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| 太阳日冕加热的高分辨率观测研究_帕力旦木（13522KB） | 学位论文 | 暂不开放 | CC BY-NC-SA | Application Full Text | ||
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