Origin of later band-like lanes following the Type II burst

Determine the physical origin of the two later lanes or bands observed around 14:15 UT in the I-LOFAR dynamic spectrum on 10 May 2022 that mirror the end of the Type II radio burst and exhibit band-splitting, specifying the emission mechanism and source region responsible for these features.

Background

During the 10 May 2022 event, I-LOFAR recorded a Type II radio burst with clear fundamental and harmonic bands exhibiting band-splitting, along with fine structures such as herringbones. Near the end of the Type II burst (approximately 14:15 UT), two additional lanes appeared in the dynamic spectrum that mirrored the end of the Type II burst in time-frequency morphology and also appeared to show band-splitting.

The authors explicitly note that the source of these later bands is unknown. Clarifying whether these delayed bands are a continuation of shock-related emission, a separate emission process, or an artifact related to propagation or instrumental effects is necessary to understand the shock dynamics and electron acceleration processes during the event.

References

An interesting phenomenon observed at the end of the Type II burst (approx. 14:15~UT) is the appearance of two further lanes or bands that mirror the end of the Type II burst but at a later time. These later bands also appear to display band-splitting but their source is unknown.

— Tracking the motion of a shock along a channel in the low solar corona  (2403.17659 - Rigney et al., 2024) in Section 3.1, Dynamic spectrum

Present observations cannot distinguish between shock corrugation and large-scale coronal inhomogeneity, but they provide strong evidence that the multilane emission is related to spatial variations in the local shock geometry and Mach number rather than variations in propagation speed alone.

— Multi-lane type II radio bursts: Insights into shock propagation in the corona  (2608.19295 - K. et al., 19 Aug 2026) in Section 4, Discussion and conclusion