Gas temperature estimation from the ratio between o-H₂CO 3_0,3 − 2_0,2 and o-H₂CO 3_2,2 − 2_2,1, following the results from Mangum & Wootten (1993). Specific values of 60, 90, and 120 K are shown by blue, green, and red contours, respectively. The grey region, where o-H₂ CO 3_2,2 − 2_2,1 is not detected, indicates temperatures below 50 K. The yellow stars show the position of the sources and the solid segment represents the extent of the circumbinary disc. The synthesised beam is represented by a black filled ellipse.