High-resolution studies of dynamic processes in the sunspot umbra: Preparing for the era of the Daniel K. Inouye Solar Telescope

太阳黑子是太阳表面温度降低的区域，相对于周围区域表现为暗斑。它们是集中磁场的结果，并可能与产生太阳耀斑和日冕物质抛射(CME)等空间天气事件的磁活动区域有关。太阳黑子动力学和演化的研究是太阳物理领域的一个重要研究领域。偶尔，较亮的物质区域会穿过太阳黑子的暗中心(即本影)，形成所谓的“光桥”。这项计划将使用由国际和平研究所运营的新太阳望远镜(NST)以及基于卫星的数据来研究与这些光桥相关的三维结构和磁场。拟议的研究将支持对下一代太阳科学家的培训。PI将包括一名博士生和一名本科生暑期学生参与拟议的研究。这项提议将研究在太阳黑子本影中观察到的光桥的动力学，以及色球、日冕和两者之间的过渡区域中的相关活动。这项研究的动机是使用NST对太阳黑子进行高分辨率观测的能力。定向观测将研究色球和太阳黑子上方过渡区的精细结构。在色球和过渡区看到的本影喷流、动态纤维和结构上升流等现象表明，动力学相对来说还没有被研究过，也没有被很好地理解。该提议描述了这项工作的四个主要目标，包括：1)测量和了解太阳黑子光桥中的动力学磁场；2)研究太阳黑子光桥中反常斯托克斯轮廓的形状并确定它们在触发高能事件中的作用；3)研究光球动力学与色球/日冕外流之间的联系；以及4)研究本影闪光和尖峰的空间结构、动力学和光谱特性。提案中概述的工作将为丹尼尔·K·井上太阳望远镜(DKIST)的科学规划和成功提供重要的预备科学。

Sunspots are areas of reduced temperature on the surface of the sun that appear as dark spots relative to the surrounding regions. They are the result of concentrated magnetic fields and can be associated with magnetically active regions that produce space weather events like solar flares and coronal mass ejections (CMEs). The study of sunspot dynamics and evolution is an important area of research in the field of solar physics. Occasionally, regions of brighter material cross the dark center of the sunspot (known as the umbra) to form what is called a "light bridge". This proposal will use the New Solar Telescope (NST) operated by the PI's institution along with satellite-based data to study the three dimensional structure and magnetic fields associated with these light bridges. The proposed research will support the training of the next generation of solar scientists. The PI will involve both a PhD graduate student and an undergraduate summer student in the proposed research. This proposal will investigate the dynamics of light bridges observed in the umbra of sunspots and the associated activity in the chromosphere, the corona, and the transition region between the two. This research is motivated by the capability to make high-resolution observations of sunspots using the NST. Targeted observations will study the fine-scale structure of the chromosphere and the transition region above sunspots. Phenomena such as umbral jets, dynamic fibrils, and structured up-flows seen in the chromosphere and the transition region suggest that the dynamics are relatively unexplored and not well understood. The proposal describes four major goals of the work including: 1) measuring and understanding the dynamics magnetic fields in sunspot light bridges, 2) studying the shape of anomalous Stokes profiles in sunspot light bridges and determining their roles in triggering energetic events, 3) investigating the connection between photospheric dynamics and chromospheric/coronal outflows, and 4) studying the spatial structure, dynamics, and spectral properties of umbral flashes and spikes. The work outlined in the proposal will provide important preparatory science beneficial to the science planning and success of the Daniel K. Inouye Solar Telescope (DKIST).