Comparing the multiple velocity components of the H₂CO 3(0,3)−2(0,2) emission. Upper left: H₂CO 3(0,3)−2(0,2) spectrum (black) with velocity resolution 0.17 km s⁻¹ covering the full velocity range of −5 to 15 km s⁻¹, extracted from the region where HDCO 4(2,2)−3(2,1) emission is above 4σ, overlaid with the best fit (pink) obtained using four Gaussian fits with FWHM, υ_LSR and T_ex constrained using values obtained from fitting the HDCO transitions. A continuum value of 10.3 K has been added to this spectrum in order to model the absorption feature located at the systemic velocity of 3.6 km s⁻¹. Upper right, lower left, lower right: H₂CO 3(0,3)−2(0,2) moment 0 map integrated between −5 and 0 km s⁻¹, between 0 and 8 km s⁻¹ and between 8 and 15 km s⁻¹, respectively, in order to individually show the velocity components of emission shown in the upper left panel. Contours begin at 4σ and are in increments of 8σ (σ = 17.6 mJy beam⁻¹ km s⁻¹). The pink contour illustrates the area within which the spectrum in the upper left panel was extracted, defined as the 4σ contour of the HDCO 4(2,2)−3(2,1) moment 0 map (see Fig. 4). The ALMA synthesised beam is in the lower left corner of all three maps.