Integrated velocity ranges (blue, gray, and red contours) for each molecular line tracer. Contour levels start from 0.2 Jy beam⁻¹ km s⁻¹ (equivalent to 3.3–7σ), except for H₂CO (0.4 Jy beam⁻¹ km s⁻¹, rms noise levels poorly quantified due to lack of emission-free regions), H₂¹³CO (0.1 Jy beam⁻¹ km s⁻¹, ~3.5–5σ), ²⁹SiO and C₂H (both 0.07 Jy beam⁻¹ km s⁻¹, ~1.6–3.5σ), and increase by a factor of two to the next level. Equivalent negative contours are plotted in dashed style. The 0.87 mm continuum emission is shown in grayscale, stretching from 0.002 to 2.0 Jy beam⁻¹. We note that in the SiO 8–7 panel, the scattered, compact, negative value contours with angular sizes less than one beam are not real signal, but artefacts from the continuum subtraction process.