SABOCA 350-μm and LABOCA 870-μm images of the I05399/SMM 1-system. The images are shown with linear scaling, and the colour bars indicate the surface-brightness scale in Jy beam^-1. The overlaid SABOCA contours start at three times the noise level (3σ = 240 mJy beam^-1) and increase at this interval to 1680 mJy beam^-1. The LABOCA contour levels range from 90 mJy beam^-1 (3σ) to 720 mJy beam^-1, increasing in steps of 3σ. The green plus signs show the target positions of our previous molecular-line observations. A scale bar indicating the 0.1 pc projected length is shown in the left panel, with the assumption of a 450 pc line-of-sight distance. The effective beam sizes ( for SABOCA, for LABOCA) are shown in the lower left corner of the panels.