Constraints on the nuclear emission of the Circinus galaxy: the torus

In the context of the unified model of Seyfert galaxies, we use observation s from the literature and a radiative transfer model to investigate the nea r-IR to mm emission produced by the presumed torus in the Circinus galaxy, from 2 mum to 1.3 mm. From the infrared SED modelling, we find that the tot al luminosity (L-IR) in this wavelength range consists of similar contribut ions from the torus and starburst with a ratio of nuclear luminosity to sta rburst luminosity (L-NUC/L-SB) similar to0.8. By using a similar torus model to that of NGC 1068, but without the conical dust, we find an upper limit to the outer torus radius of similar to 12 pc with a best fit of similar to2 pc. The upper limit torus size estimated fr om the radiative transfer modelling is consistent with the 16-pc torus radi us estimated from near-IR imaging polarimetry of Circinus.