PACS continuum levels at 80, 130 and 180 μm (red contours) superimposed on a Spitzer/MIPS 70 μm images around SMM3 and SMM4 (upper and lower panels, respectively). Green contours show the 450 μm continuum observed with SCUBA, while the yellow and red dots depict the position of the sources reported in Harvey et al. (2007) and Hogerheijde et al. (1999). PACS and SCUBA levels start at 2 Jy and increase by 2 Jy and 1.5 Jy steps, respectively.