2D histograms of the ¹²CO, HCN, HCO⁺, HNC, J = 1–0, and [C I]³P₁ – ³P₀ line intensities as a function of FIR intensity in Orion B (from maps at 120″ resolution). The dashed red lines show the running median (median values of the integrated intensity within equally spaced log I_FIR bins). The error bars show their dispersion. Black lines (and associated text) show a linear fit (orthogonal regression in log(y)-log(x)) to all observed positions in each map. Magenta lines and blue lines show a linear fit to a range of I_FIR <6 × 10⁻³ erg s⁻¹ cm⁻² sr⁻¹ and (0.4–7.7) erg s⁻¹ cm⁻² sr⁻¹, respectively. We note that in each plot the number of line detections is different.