Integrated intensity map for the 6₋₁ → 5₀ − E methanol line at 132.9 GHz (within a velocity interval of v_sys ≲ ±200 km s⁻¹). Selected positions for spectral extraction (Sect. 3) are encircled in beam-sized apertures and numbered from 1 to 10. The center and edges of the inner Lindblad resonance from Iodice et al. (2014) are denoted with a black ellipse and dash-dotted gray ellipses, respectively. Superbubbles identified by Sakamoto et al. (2006) are indicated as orange circles. The ALMA beam () is shown in blue in the bottom left corner.