A model for the ¹²CO lines with υ_turb = 0.7 km s^-1 (short-dashed blue line) is compared to the best model found in Paper I (υ_turb = 1.4 km s^-1; dotted-dashed brown line). The observed ¹²CO lines are shown in red. The adopted value for the υ_LSR of 40.4 km s^-1 was subtracted from the observed lines. The lines J = 16 − 15, 10 − 9 and 6 − 5 were observed with HIFI, J = 4 − 3 and 3 − 2 with APEX, J = 2 − 1 with SMT and J = 1 − 0 with SEST.