Implications of radio observations for magnetic reconnection and particle acceleration in solar eruptions
Abstract
Radio emissions are tracers of non-thermal electrons ranging from suprathermal to relativistic energies. They are observed during flares and CMEs, but also from non flaring active regions and perhaps even the quiet Sun. There is a broad diversity of radio features, observed in spectroscopic or imaging data, that have been tentatively related to magnetic reconnection : - microwave source morphologies, which suggest energy release during the interaction of different plasma structures ; - quasi-periodic bursts related with the formation of plasma ejections, ascribed to the formation of plasmoids in reconnecting current sheets ; - narrow-band non drifting radio emissions, interpreted as signatures of reconnection shocks because of their similarity with emissions from travelling shocks ; - radio emissions revealing time-extended electron acceleration in extended flare events, related with the relaxation of the corona in the aftermath of a CME. Various other types of emission from flares or non-flaring active regions point to an origin in coronal current sheets or a relationship with cancelling magnetic features in the photosphere. We'll present relevant observations and discuss the constraints they provide on models of energy release and particle acceleration related to flares, CMEs, and quiescent active regions.
- Publication:
-
37th COSPAR Scientific Assembly
- Pub Date:
- 2008
- Bibcode:
- 2008cosp...37.1538K