Integrated intensity map of the [CII] 158 μm emission overlaid with integrated intensity contours (orange) from 600 to 1000 K km s⁻¹ in steps of 100 K km s⁻¹ toward OMC-1, adapted from Pabst et al. (2019). The positions observed using the KP 12 m telescope are marked by blue crosses, while the blue circles represent the KP beam. The corresponding calibrated and baseline subtracted o-CH₂ spectra are displayed alongside the map. The individual fits to the HFS components are displayed by dotted blue curves while solid red curves displays the combined fit. The positions and relative intensities of the HFS components are marked below the spectra. The dashed blue line indicates the systemic velocities of the sources which lie between +7 and +11 km s⁻¹. In light blue we also mark the CH₃CCH lines covered in the 68 375 MHz spectrum toward Orion S. The velocity scale is set by the F′ − F′′ = J–J − 1 HFS line (see Table 1).