a) ALMA-ACA averaged intensity cuts perpendicular to the Orion Bar. Except for CO J = 3−2 line (peak temperature in K), cuts show integrated line intensities (in K km s^-1). Symbols do not have any meaning, they are used to improve figure readability. b) Isobaric model of a PDR with P_th/k = 2 × 10⁸ K cm^-3 and χ = 10⁴. In both figures, the FUV radiation from the Trapezium cluster comes from the right-hand side.