Maps of the column density gradient oriented angles (left) and the velocity gradient oriented angles (middle) in the Horsehead nebula from the main-velocity layer from the ¹³CO (1–0) (top) and the C¹⁸O (1–0) (bottom) emission. Right: maps of the relative orientation between the oriented angles of the column density and the velocity gradients. Oriented angles are defined north from east. The black lines show the filamentary structure and the diamond dots show the dense cores identified by the Herschel Gould Belt Survey (Könyves et al. 2020).