AGN-driven galactic outflows: comparing models to observations
  The actual mechanism(s) powering galactic outflows in active galactic nuclei
(AGN) is still a matter of debate. At least two physical models have been
considered in the literature: wind shocks and radiation pressure on dust. Here
we provide a first quantitative comparison of the AGN radiative feedback
scenario with observations of galactic outflows. We directly compare our
radiation pressure-driven shell models with the observational data from the
most recent compilation of molecular outflows on galactic scales. We show that
the observed dynamics and energetics of galactic outflows can be reproduced by
AGN radiative feedback, with the inclusion of radiation trapping and/or
luminosity evolution. The predicted scalings of the outflow energetics with AGN
luminosity can also quantitatively account for the observational scaling
relations. Furthermore, sources with both ultra-fast and molecular outflow
detections are found to be located in the `forbidden' region of the
$N_\mathrm{H} - \lambda$ plane. Overall, an encouraging agreement is obtained
over a wide range of AGN and host galaxy parameters. We discuss our results in
the context of recent observational findings and numerical simulations. In
conclusion, AGN radiative feedback is a promising mechanism for driving
galactic outflows that should be considered, alongside wind feedback, in the
interpretation of future observational data.
