Location of emission of the forsterite 69 μm features, split into its different temperature components for models R20 (left) and RW30 (right). Overplotted is the radial τ = 1 surface in the optical. Contours are given as a fraction of the maximum emission of the total feature, between 1 and 10% (light grey) and 10 and 100% (dark grey). The emission has been integrated over the azimuthal direction.