Solar ultraviolet bursts in a coordinated observation of IRIS,Hinode and SDO

作     者：CHEN YaJie TIAN Hui ZHU XiaoShuai SAMANTA Tanmoy WANG LingHua HE JianSen 

作者机构：School of Earth and Space SciencesPeking UniversityBeijing 100871China Max Planck Institute for Solar System ResearchGottingen 37077Germany 

出 版 物：《Science China(Technological Sciences)》 (中国科学（技术科学英文版）)

年 卷 期：2019年第62卷第9期

页      面：1555-1564页

核心收录：

学科分类：08[工学] 0802[工学-机械工程] 

基　　金：supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA17040507) the National Natural Science Foundation of China(Grant Nos.11825301,11790304(11790300),41774183&41861134033) the Strategic Pioneer Program on Space Science of Chinese Academy of Sciences(Grant Nos.XDA15011000&XDA15010900) 

主　　题：Sun: chromosphere Sun: transition region Sun: UV radiation magnetic reconnection 

摘      要：Solar ultraviolet（UV） bursts are small-scale compact brightenings in transition region images. The spectral profiles of transition region lines in these bursts are significantly enhanced and broadened, often with chromospheric absorption lines such as Ni ii 1335.203 and 1393.330 ? superimposed. We investigate the properties of several UV bursts using a coordinated observation of the Interface Region Imaging Spectrograph（IRIS）, Solar Dynamics Observatory（SDO）, and Hinode on February 7, 2015. We have identified 12 UV bursts, and 11 of them reveal small blueshifts of the Ni ii absorption lines. However, the Ni ii lines in one UV burst exhibit obvious redshifts of ～20 km s-1, which appear to be related to the cold plasma downflows observed in the IRIS slit-jaw images. We also examine the three-dimensional magnetic field topology using a magnetohydrostatic model, and find that some UV bursts are associated with magnetic null points or bald patches. In addition, we find that these UV bursts reveal no obvious coronal signatures from the observations of the Atmospheric Imaging Assembly（AIA） on board SDO and the EUV Imaging Spectrometer（EIS） on board Hinode.