Overlay of the map of the 1.3 mm continuum emission obtained with the very extended SMA configuration (contours) on the map of the first moment of the C₂H₅CN (25_2,24–24_2,23) second velocity component (color scale). Contour levels are the same as in Fig. 1. Offsets are measured with respect to the phase center. The triangle marks the position of the HC Hii region in G24 A1 (Beltrán et al. 2007) and the crosses the position of sources A1 and A1b.