Coronal Energetics and Loop Dynamics

准确地确定等离子体温度分布是理解日冕环的动力学、密度和填充因子的必要的第一步。日冕环是由热等离子体填充的封闭磁场结构，主导着太阳的高能发射。这些量在确定区域的能量平衡和供暖要求、日冕环路稳定性以及在给定特征下的辐射损失和传导冷却的计算中是重要的输入。这项拟议的工作将研究日冕环的温度分布、密度结构和时间演变。有了这些信息，并通过使用先前测量的日冕磁场、元素丰度、整体流动、波动和湍流运动的估计，可以确定不同(可能不同类型)日冕环路的主要能量损失机制。该项目将来自太阳和日球层天文台(SOHO)日冕诊断光谱仪的高分辨率极紫外光谱线数据与来自其他仪器的极紫外和X射线成像数据相结合。这些观测结果将与各种日冕加热机制预测的温度分布相比较，以确定这些机制中的哪一种(如果有的话)负责环状加热。详细的定量结果将提供给研究日冕加热的理论家。此外，这项调查将改进仪器的温度交叉校准，并量化使用各个数据集所固有的不确定性。由此产生的算法将通过将它们集成到现有的软件库中而提供给科学界。研究生和本科生将在拟议的分析中发挥关键作用。相关的外展项目名为《破解星光密码》，通过回答这样一个问题，向来自孟菲斯市中心学校系统的五年级学生介绍光谱学的基础知识：恒星是由什么组成的？太多的当地学生认为答案更多地与魔法有关，而不是物理。Starlight教授学生如何使用光谱学来寻找答案。一群五年级的学生来大学参加星光计划的实地考察，或者一队本科生直接把星光带到教室里。该项目起初规模很小，大约有10个班级，每班25名学生，但参与过星光计划的学生和教师人数现在已经达到5000人。

An accurate determination of the plasma temperature distribution is an essential first step to understanding the dynamics, density, and filling factor of coronal loops, the closed magnetic field structures filled with hot plasma that dominates the high-energy emissions from the Sun. These quantities are important inputs in determining, e.g., the energy balance and heating requirements of a region, coronal loop stability, and calculations of radiative losses and conductive cooling in a given feature. This proposed effort will examine the temperature profile, density structure, and temporal evolution of coronal loops. With this information, and by using estimates of the coronal magnetic field, elemental abundances, bulk flows, waves, and turbulent motions from previous measurements, the dominant energy loss mechanisms can be determined for different (and possibly different types of) coronal loops.This project combines high-resolution EUV spectral line data from the SOlar and Heliospheric Observatory (SOHO) Coronal Diagnostics Spectrometer with EUV and X-ray imaging data from other instruments. These observational results will be compared with the temperature profiles predicted by various coronal-heating mechanisms in order to determine which of these mechanisms, if any, is responsible for the loop heating. The detailed quantitative results will be made available to theoreticians studying coronal heating. In addition, this investigation will provide improved temperature cross-calibrations of the instruments and a quantification of the uncertainties inherent in the use of the individual data sets. The resulting algorithms will be made available to the scientific community by integrating them into existing software libraries.Graduate and undergraduate students will play a vital role in the proposed analysis. The associated outreach project, Breaking the Secret Code of Starlight, introduces 5th graders from the Memphis inner-city school system to the basics of spectroscopy by answering the question, What are stars made of? Too many local students think the answer has more to do with magic than with physics. Starlight teaches students how scientists use spectroscopy to find the answer. Groups of 5th graders come to the University on field trips to participate in the Starlight program, or teams of undergraduates bring Starlight directly to the classrooms. The program started small, with about 10 classes of 25 students each, but the number of students and teachers who have participated in Starlight has now reached 5000.