Observations of a Flare-Generated Blast Wave in a Pseudo Coronal Mass Ejection Event

Abstract

We present an analysis of the event near the east limb, SOL2014-03-06T09:23, in which a pseudo coronal mass ejection (CME) was detected by the Large Angle and Spectrometric Coronagraph (LASCO) C2 instrument and indicated as "Poor Event; Only C2" in the Solar and Heliospheric Observatory (SOHO) LASCO CME Catalog. The analysis was performed based on two main methods: 1) investigation of the difference brightness profiles along specific directions in the solar corona using the EUV observations by the Atmospheric Imaging Assembly (AIA) instrument onboard the Solar Dynamics Observatory (SDO); 2) investigation of the spatially-resolved observations of the type II radio bursts made with the Nançay Radioheliograph. Based on the analysis performed we argue that the observed pseudo-CME could be a blast wave caused by impulsive flare energy release in the low corona. We also argue that, in the limited height range of ≈0.2 R_⊙-0.5 R_⊙, the front of this blast wave could steepen into a shock front.