Measurements of spectral lines observed with Hinode/EIS as implications for coronal heating

作     者：Ying Li Ming-De Ding 

作者机构：Department of Astronomy Nanjing University Nanjing 210093 China 

出 版 物：《Research in Astronomy and Astrophysics》 (天文和天体物理学研究（英文版）)

年 卷 期：2009年第9卷第7期

页      面：829-840页

核心收录：

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：supported by the National Natural Science Foundation of China under grants 10673004 and 10878002 by NKBRSF under grant 2006 CB806302 

主　　题：line: profiles   Sun: corona   Sun: UV radiation 

摘      要：We have measured the line widths and nonthermal velocities in 12 solar regions using high resolution EUV data taken by Hinode/EIS. We find that there exists a positive correlation between the intensity and nonthermal velocity for the Fe xII emission line as well as some other lines. The correlation coefficients decrease from the disk center to the limb. However, the nonthermal velocities of a particular spectral line do not vary much in different regions, so they are considered isotropic. In particular, we find that for a coronal loop structure, the largest widths and nonthermal velocities occur at the footpoints, where outflows appear. Based on these observational results, we discuss several physical processes responsible for coronal heating.