Integrated intensity maps of the Horsehead edge. Maps were rotated by 14° counter-clockwise around the projection center, located at (δx,δy) = (20′′, 0′′), to bring the exciting star direction in the horizontal direction and the horizontal zero was set at the PDR edge, delineated by the red vertical line. The crosses show the positions of the PDR (green) and the dense core (blue). The spatial resolution is plotted in the bottom left corner. Values of the contour levels are shown in the color look-up table of each image (first contour at 2σ and 2.5σ for CF⁺1 − 0 and 2 − 1 respectively). The emission of all lines is integrated between 10.1 and 11.1   km   s^-1.