Mid-infrared emission observed towards I05345 with the Spitzer Space Telescope. The two colour images show the Spitzer IRAC bands centred at 4.5 (top panel) and 8 μm (bottom panel). The white contour indicates the ammonia (1, 1) emission and is the same as in Fig. 4. The yellow circle about 15′′ above C1-a pinpoints the location of the 4.5 μm source discussed in the text (as in Fig. 4), and the other symbols indicate the location of the cores as in Fig. 1. The two grey contours represent the 3σ level of the N₂D⁺ (3−2) integrated emission, and are the same as the blue contours in Fig. 1. In each panel, The VLA synthesised beam is shown in the bottom-left corner.