Coronal Energetics and Loop Dynamics

日冕能量学和环动力学

• 批准号: 0402729
• 负责人: Joan Schmelz
• 金额: $ 48.03万
• 依托单位: University of Memphis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0402729&HistoricalAwards=false
• 关键词: Coronal; Energetics; Loop; Dynamics

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.

等离子体温度分布的准确测定是理解日冕环的动力学、密度和填充因子的重要第一步，日冕环是充满热等离子体的封闭磁场结构，主导太阳的高能发射。这些量是确定的重要输入，一个区域的能量平衡和加热要求，日冕环的稳定性，以及辐射损失和传导冷却的计算。这项提议的努力将研究日冕环的温度分布、密度结构和时间演化。有了这些信息，并通过使用以前测量的日冕磁场，元素丰度，整体流动，波和湍流运动的估计，可以确定不同的主要能量损失机制该项目将来自太阳和日光层观测站日冕诊断光谱仪的高分辨率极紫外光谱线数据与极紫外和X-射线辐射数据相结合，射线成像数据来自其他仪器。这些观测结果将与各种日冕加热机制预测的温度分布进行比较，以确定这些机制中的哪一种（如果有的话）是环路加热的原因。详细的定量结果将提供给研究日冕加热的理论家。此外，这项调查将提供改进的温度交叉校准的仪器和量化的不确定性固有的使用个别数据集。由此产生的算法将通过集成到现有的软件库中提供给科学界。研究生和本科生将在拟议的分析中发挥至关重要的作用。相关的外展项目，打破星光的秘密代码，介绍了从孟菲斯市中心的学校系统的五年级学生的光谱学的基础知识，通过回答这个问题，什么是明星？太多的当地学生认为答案与魔法的关系比与物理的关系更大。星光教会学生科学家如何使用光谱学来寻找答案。五年级学生团体来实地考察大学参加星光计划，或本科生团队直接将星光带到教室。该计划开始时规模很小，大约有10个班，每个班25名学生，但参加星光计划的学生和教师人数现已达到5000人。