Integrated intensity maps for the different transitions observed in the GC. The shown region corresponds to the rectangle (black solid line) in Fig. 2 (left). Black contour levels for the molecular line emission (on a scale) are −3, 3, 6, 9, 12, 15, 20, 30, 40, 50 σ (1σ=0.72 K km s^-1). The wedge at the side shows the intensity range of the line emission on a scale. The beam size is shown at the bottom-left corner of the left panel. The dashed line marks the Galactic plane through Sgr A^∗.