NVSS 21 cm continuum (left) and IRAM 30 m CO (1–0) (right) contours overlaid on a Spitzer-IRAC three-colour image of the secondary bubble N131-A with 4.5 μm = blue, 8 μm = green, and 24 μm = red. The contour levels start at 5σ in steps of 20σ with σ = 0.53mJy beam^-1 for the 21 cm, and at 5σ in steps of 5σ with for the CO (1–0). The numbers 1, 2, and 6 indicate fragment positions from Table 1. These two maps are taken from the zoom-in in the dashed square of Fig. 2.