Moment 0 maps of the HOCH₂CN 24_8,17∕16–23_8,16∕15, E_up = 222 K line and the CH₃NCO ν = 0 25_0,0 –24_0,0, E_up = 188 K line towards SMM1. Both lines are integrated over eight velocity bins, centred on the peak frequency of each line as determined towards SMM1-a. Positions of protostars in the SMM1 region are indicated and the beam size (1.′′ 32 × 1.′′04) is visualised in the bottom left corner. Dust continuum contours are given by the black dotted line at the levels of 0.02, 0.05, 0.1, 0.2, and 0.5 Jy Beam⁻¹.