XCLASS fitting for the IRAM 30 m H₂CO data. The panels show: integrated intensity (between −87.5 and 2.2 km s⁻¹) in the H₂CO 3_0,3 −2_0,2 (top-left) and 3_2,2−2_2,1 (bottom-left) transitions; column density in p-H₂CO (top-middle-left); excitation temperature (top-middle-right); peak velocity (bottom-middle-left); FWHM (bottom-middle-right); example spectra (black) and  XCLASS model fits (red) for H₂CO 3_0,3 −2_0,2 (top-right) and 3_2,2−2_2,1 (bottom-right). The beam is shown in the top-left panel. The black contours in the maps show the NOEMA 1.4 mm continuum smoothed to a FWHM of 0.8′′, as used for the analysis of the combined H₂CO data in Sect. 3.2, starting at 5σ and increasing to 45σ in 10σ steps. The spectra are extracted at the position covering the hot-core, which is indicated in the right-hand panels with a red square. A scale-bar is shown in the lower-left panel.