日珥及针状体精细结构的高分辨成像及光谱观测研究

Solar prominences are magnetic and dynamic structures confining a cool and dense plasma in the hot solar corona. It appears in emission when it is seen above the solar limb (and in absorption as it is seen against the solar disk). Solar spicules are elongated, thin and also highly dynamic emission features seen from the solar limb (and they are known as fibrils or mottles seen on the disk). Both of them are most remarkable features between the chromosphere and corona and may provide significant mass and energy to the corona. This proposal aim to study the prominences and macro-spicules observed from near and off solar limb with high resolution. Some new observations with unprecedented high resolution obtained by spacecrafts have shown that both features actually comprise many dynamic fine structures. High resolution observations have become very attractive because some observations have been in conflict with the models we previously knew. Therefore it is necessary to investigate the dynamic characteristic and the plasma parameters of these fine structures, in order to better understand the general properties of the prominence and spicules. In the present project we propose to use the observation facilities in Fuxian Solar Observatory, particularly the New Vacuum Solar Telescope (NVST), to obtain high-spatial and high-spectral observations of solar prominences and macro-spicules. We would like to investigate the following aspects. (1) We will study different types of motions of fine structures including field-aligned flows, swaying and torsional motions with high resolution images and spectra observations. (2) We would like take advantage of different atmosphere models and different spectral inversion techniques to infer the plasma parameters of these fine structures. (3) We attempt to carry out the spectral-polarization observation of He I 10830 in NVST in order to obtaine the magnetic field information inside prominences. This proposal, on one hand, will rich the present analysis of prominences and macro-spicules based on images observations via combining the high-spectral resolution and multi-wavelength observations.On the other hand, the observation plan involved in this proposal provides a good challenge to improve the observation capability of the NVST.

日珥和针状体是太阳色球层中最常见的具有复杂动力学特征的活动现象，是太阳边缘实测的传统目标。该课题旨在依托我国抚仙湖太阳观测站的重要观测设备，并结合其他新一代地面或空间观测设备，在亚角秒空间分辨率的条件下，对太阳日珥和巨型针状体的精细结构进行光谱以及成像观测研究。主要研究内容包括：1.综合分析日珥或针状体精细结构的各类运动模式。2.利用不同模型假设和推导方法，获得高空间分辨率的大气状态参数及其时间演化，分析精细结构之间的物理状态差别。3.力图在抚仙湖一米红外太阳望远镜（NVST）开展He I 10830 谱线的偏振观测，用以探测日珥的磁场结构及其动力学特征。该课题的意义在于：1.紧扣NVST科学目标，综合利用成像和光谱观测手段对日珥以及针状体的动力学特征及磁场特征进行分析，弥补单色像研究的局限性；2.该课可积极推动NVST各项终端设备的发展和科研队伍的壮大。

日珥和针状体是太阳色球层中最常见的、具有复杂动力学特征的活动现象，是太阳边缘实测的传统目标。本项目旨在依托我国NVST望远镜的主要观测终端---高分辨成像系统以及多波段光谱仪，围绕日珥精细结构观测研究开展高分辨成像及光谱观测。按照项目年度计划，基本完成各项科研任务。在软硬件研发、数据处理方法研究以及科学数据分析等方面都做了大量工作，并在以下研究工作上获得一定的进展。.（1）完成NVST多波段以及近红外光谱仪研制，设计并实现多种模式的光谱观测系统。 多波段光谱仪可以进行经典色球光谱(Halpha 和 Ca)的高分辨率观测和光球磁场的偏振光谱观测。.（2）提高二维空间扫描光谱观测的空间分辨率。根据NVST成像系统与光谱仪系统特殊空间布局，有效解决在扫描过程中由于太阳像晃动所造成的二维扫描结果空间分辨降低的问题。.（3）开展日珥结构的高精度空间相关对齐方法的研究。与日面数据相比，日珥数据的特点是：整体强度低、本身或内部结构的对比度低。为此，我们提出了特殊方法进行日珥结构凸显，并有效提高图像相关精度，保证后续的高分辨重建结果的质量。.（4）日珥实测与分析工作。这里主要是对两组NVST观测到的日珥进行了科学分析。第一组数据分析显示，日珥内部存在显著的双向径向流动，空穴结构也表现出了明显的塌缩和振动活动特点。第二组数据分析发现，由于存在剪切速度的存在，日珥内部的精细结构出现不同尺度的振荡以及旋涡结构，对空间等离子体亥姆赫兹不稳定性的研究提供了良好的观测证据。.（5）暗条磁场拓扑结构分析。NVST观测到了一系列同源的、伴随暗条爆发的环形耀斑过程，我们从磁场拓扑结构的角度来分析了触发暗条爆以及耀斑的原因。..所存在的问题: 1. 由于多方面原因，在偏振测量方面未能按原计划开展的近红外偏振测量，取而代之，在可见光偏振测量方面有了较为扎实的推进。2. 光谱仪与AO对接工作暂时仍处于试验阶段，有待于尽快投入常规运行。..在项目执行过程中，积极开展国际合作，完成多次国际联合观测计划，参加多次国内、国际会议和学术交流。