A Flare-Generated Shock during a Coronal Mass Ejection on 24 December 1996

摘要

We present a multiwavelength study of the large-scale coronal disturbances associated with the CME – flare event recorded on 24 December 1996. The kinematics of the shock wave signature, the type II radio burst, is analyzed and compared with the flare evolution and the CME kinematics. We employ radio dynamic spectra, position of the Nançay Radioheliograph sources, and LASCO-C1 observations, providing detailed study of this limb event. The obtained velocity of the shock wave is significantly higher than the contemporaneous CME velocity (1000 and 235 km s−1, respectively). Moreover, since the main acceleration phase of the CME took place 10 – 20 min after the shock wave was launched, we conclude that the shock wave on 24 December 1996 was probably not driven by the CME. However, the shock wave was closely associated with the flare impulsive phase, indicating that it was ignited by the energy release in the flare.