Southern field Hα emission in color, with 100 μm PACS emission in black contours. Four CO spectra in the southern field where the signal is well above the noise are shown, with the precise positions indicated with red or black triangles. The 21 cm spectrum at the location of the detected CO line is shown in cyan. The thick red contour indicates the extent of the CO map. The white contour between the Hα emitting zones shows the N_HI = 1.8 × 10²¹ cm⁻² column density level (in the rest of the region, the HI column densities are lower than the contour value).