Observations of AGN host galaxies have detected fast molecular outflows, with velocities up to ~1000 km/s and outflow rates up to ~1000 Msol/yr. To explore the origin of these molecular outflows, we ran simulations of an isotropic AGN wind interacting with a uniform ambient ISM. By modelling the time-dependent molecular chemistry in these simulations, we showed that these molecular outflows can arise from the in-situ formation of molecules within the AGN wind. In this talk, I will present the results of radiative transfer modelling of molecular emission lines from these simulations in post-processing. We found that the molecular outflow rates derived from CO emission lines in our simulations at solar metallicity are in agreement with observations. By comparing the CO emission to the actual H2 mass in the simulations, we derive a CO-to-H2 conversion factor of 0.13 Msol/(K km/s pc^2), a factor of 6 lower than the standard ULIRG value that is often assumed in these observations. We also found strong infrared emission lines from warm H2, with excitation temperatures of 400-550 K. The mass of H2 inferred from this warm H2 emission is within a few per cent of the total H2 mass. These warm H2 emission lines are potentially observable by JWST.
|Date made available
|Mar 16 2018