Scenario of the type II burst associated with filament–filament interaction. (a) Overview of the filament–filament interaction. The red line indicates erupting F1. The blue lines indicate erupting F2. The green line indicates the overlying loops constraining two filaments. The yellow “X” indicates the interaction between the erupting F1 and F2. (b) Formation of the type II burst. The lines change from red to blue and the lines change from blue to red indicate the productions of the magnetic reconnection between F1 and F2. Green and black lines indicate the CME and CME-driven shock, respectively. The possible location of the type II burst is marked on the flank of the shock wave.