Study of temporal and spectral characteristics of the X-ray emission from solar flares

作     者：Veena Choithani Rajmal Jain Arun K.Awasthi Geetanjali Singh Sneha Chaudhari Som Kumar Sharma 

作者机构：Dept.of PhysicsSh.M.M.Patel Institute of Sciences&ResearchKadi Sarva VishwavidyalayaGandhinagar 382015India CAS Key Laboratory of Geospace EnvironmentDepartment of Geophysics and Planetary SciencesUniversity ofScience and Technology of ChinaHefei 230026China Physical Research LaboratoryNavrangpuraAhmedabad 380009India 

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

年 卷 期：2018年第18卷第10期

页      面：33-48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：the Gujarat Council on Science and Technology(GUJCOST),Dept.of Science&Technology,Govt.of Gujarat under the minor research project grants scheme GUJCOST for the financial assistance supported by NSFC(Grant Nos.41474151,41774150 and 4171101125) the International Postdoctoral Program of USTC 

主　　题：Sun X-rays, gamma rays - Sun magnetic fields - Sun flares - Sun corona 

摘      要：Temporal and spectral characteristics of X-ray emission from 60 flares of intensity ≥C class observed by the Solar X-ray Spectrometer （SOXS） during 2003-2011 are presented. We analyze the X-ray emission observed in four and three energy bands by the Si and Cadmium-Zinc-Telluride （CZT） detectors, respectively. The number of peaks in the intensity profile of the flares varies between 1 and 3. We find moderate correlation （R ~=0.2） between the rise time and the peak flux of the first peak of the flare irrespective of energy band, which is indicative of its energy-independent nature. Moreover, the magnetic field complexity of the flaring region is found to be highly anti-correlated （R = 0.61） with the rise time of the flares while positively correlated （R = 0.28） with the peak flux of the flare. The time delay between the peak of the X-ray emission in a given energy band and that in 25-30keV decreases with increasing energy, suggesting conduction cooling is dominant in the lower energies. Analysis of 340 spectra from 14 flares reveals that the peak of differential emission measure （DEM） evolution is delayed by 60-360 s relative to that of the temperature, and this time delay is inversely proportional to the peak flux of the flare. We conclude that temporal and intensity characteristics of flares are dependent on energy as well as the magnetic field configuration of the active region.