Spatial distribution of the integrated intensity of the stacked lines of C₆H₅CN at different velocities. The selected velocity range is ±0.1 km s⁻¹ around the velocity indicated in the upper right corner of each panel (in km s⁻¹). The sampling of the data is 20″ and the integrating area in each position corresponds to a circle of 20″ radius. The white and black contours represent the integrated intensity of the J = 28-27 transition of HC₇N at the same velocity (±0.1 km s⁻¹). The first white contour corresponds to 2 mK km s⁻¹ and the step is 4 mK km s⁻¹. The first black contour corresponds to 20 mK km s⁻¹ and the step is 6 mK km s⁻¹. The white or black dot indicates the centre of the map.