Parsec-scale Dusty Winds in Active Galactic Nuclei: Evidence for
  Radiation Pressure Driving
  Infrared interferometry of local AGN has revealed a warm (~300K-400K) polar
dust structure that cannot be trivially explained by the putative dust torus of
the unified model. This led to the development of the disk+wind scenario which
comprises of a hot (~1000K) compact equatorial dust disk and a polar dust wind.
This wind is assumed to be driven by radiation pressure and, therefore, we
would expect that long term variation in radiation pressure would influence the
dust distribution. In this paper we attempt to quantify if and how the dust
distribution changes with radiation pressure. We analyse so far unpublished
VLTI/MIDI data on 8 AGN and use previous results on 25 more to create a sample
of 33 AGN. This sample comprises all AGN successfully observed with VLTI/MIDI.
For each AGN, we calculate the Eddington ratio, using the intrinsic 2-10keV
X-ray luminosity and black hole mass, and compare this to the resolved dust
emission fraction as seen by MIDI. We tentatively conclude that there is more
dust in the wind at higher Eddington ratios, at least in type 2 AGN where such
an effect is expected to be more easily visible.
