Three-color composite image of the Serpens filament (Berschel 70 µm: blue, Berschel 250 µm: green, Berschel 500 µm: red). The three green pluses indicate the positions of the three embedded YSOs, emb10 (also knupown as IRAS 18262+0050), emb16, and emb28 (Enoch et al. 2009), while the crosses mark the positions of 1.1 mm dust cores (Enoch et al. 2007). The beam size (36″.3) for the 500 µm emission is shown in the lower right corner. The regions mapped with the IRAM-30 m and APEX telescopes are indicated by the red and white dashed boxes, respectively.