Jebaraj, Immanuel Christopher ; Magdalenic, Jasmina ; Scolini, Camilla ; Rodriguez, Luciano ; Kilpua, Emilia ; Krupar, Vratislav ; Poedts, Stefan

Talk presented at SHINE 2019, Boulder, Colorado on 2019-08-05

Abstract: We present study of the CME/flare event on September 27/28, 2012. The GOES C3.7 flare that originated from NOAA AR 1577 was associated with a full-halo CME (first seen in the SOHO/LASCO C2 field of view at 23:47 UT) and white-light shock wave observed by all three spacecraft STEREO A, STEREO B, and SOHO. The associated radio event is composed of a groups of type III bursts (fast electron beams) and two type II bursts (shock waves) with different starting time and starting frequencies. We were able to clearly separate groups of type III bursts associated with impulsive and decay phase of the flare. We found the origin of the type II bursts to be significantly more complex than in the case of the type III bursts. Whilst the first type II burst shows clear association with the acceleration phase of the CME, the second type II is of unclear origin. To understand the association of the radio emission and the CME/flare event, we perform radio triangulation study using goniopolarimetric observations by STEREO/WAVES and WIND/WAVES. We also modeled propagation of the CME using the data-driven EUHFORIA cone model (EUropean Heliospheric FORecasting Information Asset) and compared results with in-situ observations. Results of the study show completely different type III source positions for groups of bursts associated with impulsive and decay phase of the flare. We also found that while the first type II is clearly CME-driven, the second type II burst (low starting frequency) occurs significantly higher in the corona than the CME. Since the radio source positions of the second type II coincide with the group of the decay phase type III bursts, and are situated close to the nearby streamer, we believe that both type of bursts are generated during the interaction between the shock wave and the streamer.