Specific HCN (top) and HNC (bottom) intensities normalized by column density (i.e., I(X)/A_V) as function of the T_K(HCN/HNC) gas temperatures for all positions in our ISF maps with I(HCN), I(HNC) ≥ 1.0 K km s⁻¹ outside the ONC, that is, with I(H41α) ≤ 1.0 K km s⁻¹. For comparison, linear (blue dotted line) and quadratic (blue dashed line) variations of the normalized line intensities with temperature are indicated in all subpanels.