Analysis of Magnetic Shear in An X17 Solar Flare on October 28, 2003 |
| |
| Authors: | Y N Su L Golub A A Van Ballegooijen M Gros |
| |
| Institution: | (1) Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, 02138, U.S.A.;(2) Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, 210008, P. R. China;(3) Graduate University of Chinese Academy of Sciences, Beijing, P. R. China;(4) DSM/DAPNIA/Service d’Astrophysique, CEA Saclay, 91191 Gif-sur-Yvette, France |
| |
| Abstract: | An X17 class (GOES soft X-ray) two-ribbon solar flare on October 28, 2003 is analyzed in order to determine the relationship
between the timing of the impulsive phase of the flare and the magnetic shear change in the flaring region. EUV observations
made by the Transition Region and Coronal Explorer (TRACE) show a clear decrease in the shear of the flare footpoints during the flare. The shear change stopped in the middle
of the impulsive phase. The observations are interpreted in terms of the splitting of the sheared envelope field of the greatly
sheared core rope during the early phase of the flare. We have also investigated the temporal correlation between the EUV
emission from the brightenings observed by TRACE and the hard X-ray (HXR) emission (E > 150 keV) observed by the anticoincidence system (ACS) of the spectrometer SPI on board the ESA INTEGRAL satellite. The
correlation between these two emissions is very good, and the HXR sources (RHESSI) late in the flare are located within the
two EUV ribbons. These observations are favorable to the explanation that the EUV brightenings mainly result from direct bombardment
of the atmosphere by the energetic particles accelerated at the reconnection site, as does the HXR emission. However, if there
is a high temperature (T > 20 MK) HXR source close to the loop top, a contribution of thermal conduction to the EUV brightenings cannot be ruled out. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
