Propagating disturbances along a coronal loop from simultaneous EUV imaging and spectroscopic observations

作     者：Ajanta Datta S.Krishna Prasad Dipankar Banerjee 

作者机构：HKBK College of Engineering Indian Institute of Astrophysics Astrophysics Research Centre School of Mathematics and Physics Queen's University Belfast 

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

年 卷 期：2015年第15卷第7期

页      面：1027-1035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] 

主　　题：Sun: corona    oscillations    UV radiation    imaging spectroscopy 

摘      要：Propagating disturbances（PDs） were studied along an active region loop using simultaneous imaging and spectroscopy. An image sequence recorded in the Fe Ⅸ/Fe X 171  channel, from TRACE and spectral data in the Si Ⅻ 520.6  line obtained from CDS/SOHO, are analyzed. A space-time map constructed from the TRACE image sequence shows the presence of PDs close to the loop foot point propagating with an apparent speed of 39 km s-1. The periodicity was found to be 5.4 *** corresponding spectroscopic data from CDS, at a location away from the foot point, show oscillations in all three line parameters roughly at the same period. At locations farther from the foot point, the line width oscillation seems to disappear while the Doppler velocity oscillation becomes prominent. We attribute this to the signature of propagating slow waves that get affected by flows/other events close to the foot point. Spectral line profiles do not show much asymmetry, however, it is difficult to infer anything due to the broadened Gaussian shape of the CDS line profiles.