Left: smoothed and exposure-corrected excess map with ROSAT X-ray contours, as in Fig. 1. The white annulus denotes the region used for extraction of the azimuthal profile; the white vertical line denotes the origin of the azimuthal angle (north), which increases in the counterclockwise direction. The green star indicates the position of PSR J0855−4644. The white dot-dashed line indicates a point-like region around the position of the southern enhancement. Right: azimuthal profile extracted from the annulus in the skymap on the left panel is shown in blue for the H.E.S.S. γ-ray data (left scale) and in red for the ROSAT X-ray data (right scale). For better visibility, two periods separated by a dashed gray line are shown. The azimuthal position of PSR J0855−4644 and the center of the region around the southern enhancement are indicated by green and black vertical dashed lines, respectively. The vertical error bars represent 1σ statistical uncertainties; the horizontal bars represent the bin widths.