Synthesising solar radio images from Atmospheric Imaging Assembly extreme-ultraviolet data  

作　　者：Zhuo-Fei Li Song-Hua Hu Xin Cheng Ming-De Ding 李卓霏;胡松华;程鑫;丁明德(School of Astronomy and Space Science,Nanjing University)

机构地区：[1]School of Astronomy and Space Science,Nanjing University,Nanjing 210023,China

出　　处：《Research in Astronomy and Astrophysics》2020年第2期37-44,共8页天文和天体物理学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11722325,11733003,11790303 and 11790300);the Jiangsu Natural Science Foundation(BK20170011);supported by the “Dengfeng B” program of Nanjing University

摘　　要：During non-flaring times,the radio flux of the Sun at wavelengths of a few centimeters to several tens of centimeters mostly originates from thermal bremsstrahlung emission,very similar to extremeultraviolet(EUV) radiation.Owing to such a proximity,it is feasible to investigate the relationship between the EUV emission and radio emission in a quantitative way.In this paper,we reconstruct the radio images of the Sun through the differential emission measure obtained from multi-wavelength EUV images of the Atmospheric Imaging Assembly on board Solar Dynamics Observatory(SDO).Through comparing the synthetic radio images at 6 GHz with those observed by the Siberian Radioheliograph,we find that the predicted radio flux is qualitatively consistent with the observed value,confirming thermal origin of the coronal radio emission during non-flaring times.The results further show that the predicted radio flux is closer to the observations in the case that includes the contribution of plasma with temperatures above 3 MK than in the case of only involving low temperature plasma,as was usually done in the pre-SDO era.We also discuss applications of the method and uncertainties of the results.During non-flaring times,the radio flux of the Sun at wavelengths of a few centimeters to several tens of centimeters mostly originates from thermal bremsstrahlung emission,very similar to extremeultraviolet(EUV) radiation.Owing to such a proximity,it is feasible to investigate the relationship between the EUV emission and radio emission in a quantitative way.In this paper,we reconstruct the radio images of the Sun through the differential emission measure obtained from multi-wavelength EUV images of the Atmospheric Imaging Assembly on board Solar Dynamics Observatory(SDO).Through comparing the synthetic radio images at 6 GHz with those observed by the Siberian Radioheliograph,we find that the predicted radio flux is qualitatively consistent with the observed value,confirming thermal origin of the coronal radio emission during non-flaring times.The results further show that the predicted radio flux is closer to the observations in the case that includes the contribution of plasma with temperatures above 3 MK than in the case of only involving low temperature plasma,as was usually done in the pre-SDO era.We also discuss applications of the method and uncertainties of the results.

关 键 词：Sun:radio radiation Sun:atmosphere Sun:UV radiation 

分 类 号：P162.11[天文地球—天文学]