Speaker: Prof Philippa Browning (University of Manchester)
Title: Heating and particle acceleration in twisted flux ropes in solar and stellar flares
Zoom link: https://zoom.us/j/95338171418
Meeting ID: 953 3817 1418
Abstract:
Twisted magnetic flux ropes are reservoirs of free magnetic energy. I will describe some recent advances in modelling plasma heating and non-thermal particle acceleration in twisted magnetic flux ropes in the context of solar flares. After an overview of twisted magnetic flux ropes in the corona, I will show how magnetic reconnection in fragmented current structures in kink-unstable twisted loops can both heat plasma and efficiently accelerate both electrons and ions. Forward modelling of the observational signatures of this process in EUV, hard X-rays and microwaves will be described, and the potential for observational identification of twisted magnetic fields in the solar corona discussed. Furthermore, the reconnection activity can drive oscillations which may be observable as oscillations in the microwave emission.
Then, coronal loops with multiple twisted threads will be considered, showing how instability in a single unstable twisted thread may trigger reconnection with stable neighbours, releasing their stored energy and causing an “avalanche” of heating events, with important implications for solar coronal heating. This avalanche can also accelerate charged particles throughout the structure.
Many other stars exhibit flares, and I will briefly describe recent work on modelling radio emission in flares in young stars (T Tauri stars). In particular, the enhanced radio luminosity of these stars relative to scaling laws for the Sun and other Main Sequence stars will be discussed.
With warmest regards,
Marianna Korsos, Chris Nelson, and Jiajia Liu
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