Top left: the 1′ × 1′ image of the nebula around WRAY 15-751 observed with PACS at 70 μm. North is up and east to the left. Top right: the synthetic image computed with 2-Dust using r_in = 7″ and r_out = 21″ and convolved with the PACS PSF. Bottom: East-west cuts through the central part of the nebula, observed (black) and synthetic (red). The upper plots correspond to the 70 μm image, the lower ones to the 100 μm image.