Dust emission at 870 μm corresponding to regions B and C. Upper-left panel: dust emission for the filament and the southern clump (region B) in contours and grayscale. The image is smoothed to 25′′. The grayscale goes from 10 to 150 mJy beam^-1, and the contours correspond to 20 to 100 mJy beam^-1 in steps of 20 mJy beam^-1. The position of candidate YSOs is indicated: 2MASS sources (crosses) and Spitzer sources (filled circles) (see Sect. 6). The position of the IRAS source is indicated by a star. Upper-right panel: overlay of the IRAC emission at 8 μm in grayscale and the 870 μm image in contours. The grayscale goes from 28 to 50 MJy sr^-1. Bottom-left panel: dust emission for clumps 1 and 2 (region C) in contours and grayscale. The image is smoothed to 25′′. The grayscale goes from 10 to 500 mJy beam^-1, and contours correspond to 40 to 200 mJy beam^-1 in steps of 40 mJy beam^-1, and 300 and 400 mJy beam^-1. Bottom-right panel: overlay of the IRAC emission at 8 μm in grayscale and the 870 μm image in contours. The grayscale goes from 28 to 50 MJy sr^-1. The symbols have the same meaning as in the upper panels. The position of the candidate CHII region is marked by a triangle.