Temperature maps derived with XCLASS. Each panel shows in color the temperature map (left: H₂CO, right: CH₃CN) and in black contours the 1.37 mm continuum emission. The dashed black contours show the − 5σ_cont emission andthe solid black contours start at 5σ_cont with steps increasing by a factor of two (see Table 2 for values of σ_cont for each region). Each core is marked in red and the dashed red circle indicates the outer radius of the radial temperature fit (Sect. 3.2). The beam size is shown in the bottom left corner in each panel. The pink bar in the top left corner indicates a linear spatial scale of 10 000 au. The primary beam size is indicated by a black circle and for regions with no extended H₂CO temperaturemap a smaller field of view is shown.