The Dynamical Morphologies of Flares Associated with the Two Types of Solar Coronal Mass Ejections

Abstract

In this paper we study the high-cadence TRACE observations of a sample of 28 X- and M-class flares, with particular focus on the relation between flare morphology and the two types (fast and slow) of solar coronal mass ejections (CMEs). Among the 28 flares studied, 10 are associated with fast CMEs, 10 are associated with slow CMEs, and 8 are loosely associated with a CME. We find that flares associated with fast and slow CMEs show different morphologies as groups. While all flares associated with fast CMEs show clear footpoint-separating, two-ribbon brightenings during the flare, this feature is less often seen in flares associated with slow CMEs or flares without CMEs. Meanwhile, while flares associated with slow CMEs sometimes show tubular emission structures during the flare, this feature is not found in our sample of flares associated with fast CMEs. This observational result suggests that the morphologies of flares, and hence possibly the magnetic field topologies, are different for events associated with fast and with slow CMEs.