Integrated intensity maps of all the observed transitions, which are labelled in the bottom-right corners. The contours show 20, 40, 60, 80, and 90% of the peak values, which are in order from top left to bottom right panels: 2.0, 2.0, 0.7, 4.6, 0.7, 0.15, 1.8, 1.1, 0.7 K km s⁻¹. The black cross represents the dust peak position, and the white circle is the beam size. All the maps have the same size (2′ × 2′), with the exception of N₂H⁺ (1–0), which is 4′ × 4′: in this map the white rectangle shows the smaller coverage of the other transitions. Scalebars are shown in the top-left corners of the N₂D⁺ (1–0) and N₂H⁺ (1–0) maps.