选址与日冕观测组知识库

The excitation mechanism of coronal quasi-period fast-propagating (QFP) wave trains remains unresolved. Using Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory observations, we study a narrow and a broad QFP wave trains excited one after another during the successive eruptions of filaments hosted within a fan-spine magnetic system on October 20, 2013. The consecutive occurrence of these two types of QFP wave trains in the same event provides an excellent opportunity to explore their excitation mechanisms and compare their physical parameters. Our observational results reveal that narrow and broad QFP wave trains exhibit distinct speeds, periods, energy fluxes, and relative intensity amplitudes, although originating from the same active region and being associated with the same GOES C2.9 flare. Using wavelet analysis, we find that the narrow QFP wave train shares a similar period with the flare itself, suggesting its possible excitation through the pulsed energy release in the magnetic reconnection process that generated the accompanying flare. On the other hand, the broad QFP wave train appears to be associated with the energy pulses released by the successive expansion and unwinding of filament threads. Additionally, it is plausible that the broad QFP wave train was also excited by the sequential stretching of closed magnetic field lines driven by the erupting filament. These findings shed light on the different excitation mechanisms and origins of the QFP wave trains.