Broad and Bidirectional Narrow Quasiperiodic Fast-propagating Wave Trains Associated with a Filament-driven Halo Coronal Mass Ejection on 2023 April 21

This paper presents three distinct wave trains that occurred on 2023 April 21: a broad quasiperiodic fast-propagating (QFP) wave train and bidirectional narrow QFP wave trains. The broad QFP wave train expands outward in a circular wave front, while bidirectional narrow QFP wave trains propagate in the northward and southward directions, respectively. The concurrent presence of the wave trains offers a remarkable opportunity to investigate their respective triggering mechanisms. Measurement shows that the speed of the broad QFP wave train is in the range of 300–1100 km s ^−1 in different propagating directions. There is a significant difference in the speed of the bidirectional narrow QFP wave trains: the southward propagation achieves 1400 km s ^−1 , while the northward propagation only reaches about 550 km s ^−1 accompanied by a deceleration of about 1–2 km s ^−2 . Using the wavelet analysis, we find that the periodicity of the propagating wave trains in the southward and northward directions closely matches the quasiperiodic pulsations exhibited by the flares. Based on these results, the narrow QFP wave trains were most likely excited by the intermittent energy release in the accompanying flare. In contrast, the broad QFP wave train had a tight relationship with the erupting filament, probably attributed to the unwinding motion of the erupting filament, or the leakage of the fast sausage wave train inside the filament body.