Upper panels: left: ¹³CO(3−2) emission distribution at −43.2 km s^-1 showing the molecular envelope around the S 24 bubble. Contours are 3.0 K to 6.0 K (T_mb) in steps of 1.0 K, 8.0 K, 10.0 K, and 12.0 K. Right: overlay of the same contours as in the left panel and the IRAC emission at 8 μm. The symbols have the same meaning as in Fig. 12. Middle panels: Left: ¹³CO(2−1) emission distribution at −43.2 km s^-1. Contours are from 4.0 K to 12.0 K (T_mb) in steps of 1.0 K. Right: overlay of the same contours as in the left panel and the IRAC emission at 8 μm. Bottom panels: left: C¹³O(2−1) emission distribution at −43.2 km s^-1. Contours are from 1.0 K to 4.0 K (T_mb) in steps of 0.5 K, and 5 K. Right: overlay of the same contours as in the left panel and the IRAC emission at 8 μm.