Left panels: density distribution of model I. With the logarithmic colour bars on top, a 2D distribution is shown to the left that lies in a plane containing the star S 1 and the centre of the main core SM 1, and to the right the entire model, also containing HD 147889. The panels below show the cuts along the straight white lines. White contours refer to the C¹⁸O (3−2) measurements by Liseau et al. (2010). Right panel: resulting temperature distribution of model I, with similar format as for the density distribution. The different colours in the frames below refer to the temperatures of the various dust constituents. Red: Very small grains (VSGs) and polycyclic aromatic hydrocarbons (PAHs). Green: grains with sizes between 0.03−3 μm. Blue: grains whose sizes extend up to 300 μm.