Rotational temperature maps of synthetic ALMA observations (top row) and synthetic NOEMA observations (bottom row,) shifted to a distance of 800 pc (left column) and 2000 pc (right column), obtained by fitting CH₃ CN (12_K−11_K) K = 4−6 lines simultaneously with XCLASS. Each panel contains four sub-panels corresponding to the image inclined by 10° (top left), 30° (top right), 60° (bottom left), and 80° (bottom right). The synthesised beam is shown in the bottom left corner of each set of synthetic observations. The contours correspond to the 1.37 mm continuum shown in Fig. 3. The scale used in the plots is for ease of comparison to the “true” disc mid-plane temperature shown in Fig. 9.