Resolving the nuclear dust distribution of the Seyfert 2 galaxy NGC 3081
  We report far-infrared (FIR) imaging of the Seyfert 2 galaxy NGC 3081 in the
range 70-500 micron, obtained with an unprecedented angular resolution, using
the Herschel Space Observatory instruments PACS and SPIRE. The 11 kpc (~70
arcsec) diameter star-forming ring of the galaxy appears resolved up to 250
micron. We extracted infrared (1.6-500 micron) nuclear fluxes, that is active
nucleus-dominated fluxes, and fitted them with clumpy torus models, which
successfully reproduce the FIR emission with small torus sizes. Adding the FIR
data to the near- and mid-infrared spectral energy distribution (SED) results
in a torus radial extent of Ro=4(+2/-1) pc, as well as in a flat radial
distribution of the clouds (i.e. the q parameter). At wavelengths beyond 200
micron, cold dust emission at T=28+/-1 K from the circumnuclear star-forming
ring of 2.3 kpc (~15 arcsec) in diameter starts making a contribution to the
nuclear emission. The dust in the outer parts of the galaxy is heated by the
interstellar radiation field (19+/-3 K).
