Some issues in diagnostics of solar chromospheric magnetic fields with the Mg b_2 line

作     者：Xian-Yong Bai Yuan-Yong Deng Jiang-Tao Su Guo-Ping Wang 

作者机构：Key Laboratory of Solar ActivityNational Astronomical ObservatoriesChinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of Space WeatherChinese Academy of Sciences 

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

年 卷 期：2014年第14卷第2期

页      面：193-206页

核心收录：

学科分类：0709[理学-地质学] 07[理学] 0708[理学-地球物理学] 070401[理学-天体物理] 0704[理学-天文学] 0825[工学-航空宇航科学与技术] 

基　　金：Supported by the National Natural Science Foundation of China 

主　　题：Sun： chromospheric    magnetic fields    spectral profiles： radiative transfer 

摘      要：Up to now, exact measurements of chromospheric magnetic fields have not been as successful as those done in the photosphere. We are currently engaging in diagnostics of chromospheric magnetic fields with the Mg b2 line by employing the Multi-Channel Solar Telescope at Huairou Solar Observing Station. Therefore, how to improve accuracy in the measurement is the main issue of our present study. To this end, we first study linear calibration coefficients for longitudinal and transverse components of chromospheric fields, which vary with wavelength, in the case of a weak field assumption. Then the polarization crosstalk introduced by instruments is analyzed in detail with two numerical simulation methods. Comparisons of the po- larization signals between cases with and without correction are presented. The result indicates that polarization accuracy is greatly improved after crosstalk correction.