Herschel/HIFI and IRAM 30m maps of different molecular emission lines toward OMC-1, all showing very different spatial distributions: CH⁺ J = 1–0 (strongly FUV-irradiated gas), CO J = 10–9 (extended warm gas), H₂O 3₁₂ -2₂₁ (hot shockedgas), and C¹⁸O J = 2–1 (colder and more FUV-shielded molecular gas). The color scale shows the integrated line intensity in units of W m⁻² sr⁻¹. The native angular resolution of each observation, the HPBW, is plotted in the bottom-left corner. Representative positions discussed in the text are indicated with numbers.