Results of the LVG analysis for each source. (a) kinetic temperatures (T_kin) of CH₃ OH as a function of the distance to the Trapezium; (b) column densities (N_tot) of CCH and of CH₃OH-E as afunction of the distance to the Trapezium; (c) derived gas density (n_H2) for CH₃ OH and CCH; (d) abundance ratio [CCH]/[CH₃OH-E] as a function of the distance from the Trapezium. The red- and blue- dashed lines are the derived averaged values for each parameters for CCH and CH₃OH-E respectively. The error bars are at 1σ.