[C II] intensity versus IRAC 8 μm intensity in M42 (top left: Veil Shell, bottom left: OMC4 with OMC1 (in gray scale; black-edged red points lie to the west of Orion S)), M43 (top right) and NGC 1977 (bottom right). The color scale in M42 indicates the distance from θ¹ Ori C. The division of M43 and NGC 1977 into the regions given in the legend is described in Sect. 3.2. The blue solid lines are the fits summarized in Table 4.