Intensity maps ( scale; color bar in units of K km s^-1) of para-H₂CO 3₀₃–2₀₂ (left), 3₂₂–2₂₁ (middle), and 3₂₁–2₂₀ (right) integrated from V_LSR = 4 to 14 km s^-1 of the OMC-1 cloud. Contour levels are from 1.9 to 19 K km s^-1 with steps of 1.9 K km s^-1 and from 19 to 95 K km s^-1 with steps of 9.5 K km s^-1 for para-H₂CO 3₀₃–2₀₂, and from 1.05 to 10.5 K km s^-1 with steps of 1.05 K km s^-1 and from 10.5 to 52.5 K km s^-1 with steps of 5.25 K km s^-1 for para-H₂CO 3₂₂–2₂₁ and 3₂₁–2₂₀.