Illustrations of GOLD, SILVER and BRONZE double-peaked galaxies. Left panel: Illustration of a GOLD double-peaked galaxy. The emission of each peak (red circle) is located inside the segmentation map (black contour) at the same spatial location. Middle panel: SILVER category. Each peak of the double-peaked Lyα line is coming from two different locations inside the segmentation map. Right panel: Case of a BRONZE galaxy. The blue peak (A) is emitted in a certain region and the red peak (B) is emitted in a different region of the segmentation map.