Energy-transfer pathways that heat hot coronal loops during LDGRFs

Ascertain the precise energy-transfer pathways by which turbulent wave activity and trapped particle populations transfer energy to heat plasma in large-scale coronal loops during long-duration gamma-ray flares while second-order Fermi acceleration proceeds.

Background

EUV observations (94 Å) show long-lived, hot coronal loops persisting for hours over the LDGRF duration, without typical cooling signatures in other EUV channels. This behavior suggests continuous energy input into the loop system, consistent with local trapping and acceleration of particles in the loop model.

The authors note that turbulent waves (e.g., Alfvénic or compressive magnetosonic modes) interacting with both trapped particles and the plasma may provide the required heating alongside stochastic acceleration. However, the detailed mechanisms by which wave–particle interactions deposit energy into the plasma remain unspecified, motivating a focused investigation of the energy-transfer pathways.