ORIGIN OF THE IR CONTINUUM IN THE CIRCINUS GALAXY

We present infrared and millimeter-wave observations of the Circinus g alaxy which is at a distance of only 4 Mpc and provides the closest ex ample of an obscured Seyfert nucleus surrounded by a starburst ring. T he FWHM size of the continuum emission is found to be only similar or equal to 0.3'' (6pc) at 3-5 mu m, similar or equal to 1.3'' at 10 mu m , less than or equal to 1.5'' at 20 mu m and less than or equal to 23' ' (460pc) at 1.3 mm. The 1.3 mm measurements also provide an estimate of similar or equal to 1.6.10(8)M(circle dot) for the gas mass. It is shown using a radiative transfer code that both the observed sizes and overall spectral energy distribution, including the 9.7 mu m silicate absorption and 3.28 - 11.3 mu m PAH emission features, can be satisfa ctorily modelled by assuming that the total luminosity is dominated by dust heated by a central power law source.