Core ρ Oph A in the continuum at 350 μm, where the different evolutionary phases are identified. The position of the dominating radiative source S 1 is shown by the star symbol. The colour scale is in units of Jy beam^-1, with the circles corresponding to the beam size. The angular scale is shown at the bottom of the figure and the orientation in the sky in the upper left corner. The APEX maps of this paper have their origin at RA = 16^h26^m2790, Dec = −24°23′5700 (J2000.0).