The gas kinetic temperature (plus symbols) and the column density (crosses) when the densities of the 1.0 M_sun model are scaled with factors k_n in the range of 1–64. The column densities have been normalized with k_n. The solid lines indicate the true values and the dashed lines are the values deduced from the synthetic observations. The frames correspond to different temperature distributions as marked in the upper right hand corner of each frame.