Modelling the [Fe II] λ1.644 μm outflow and comparison with H2 and H+ kinematics in the inner 200 pc of NGC 1068

We map the kinematics of the inner (200 pc) narrow-line region (NLR) of the Seyfert 2 galaxy NGC 1068 using the instrument Near-infrared Integral Field Spectrograph and adaptive optics at the Gemini North telescope. Channel maps and position-velocity diagrams are presented at a spatial resolution of congruent to 8 pc and spectral resolution similar to 5300 in the emission lines [Fe II] lambda 1.644 mu m, H-2 lambda 2.122 mu m and Br gamma. The [Fe II] emission line provides a better coverage of the NLR outflow than the previously used [O III] lambda 5007 emission line, extending beyond the area of the bipolar cone observed in Br gamma and [O III]. This is mainly due to the contribution of the redshifted channels to the north-east of the nucleus, supporting its origin in a partial ionized zone with additional contribution from shocks of the outflowing gas with the galactic disc. We modelled the kinematics and geometry of the [Fe II] emitting gas finding good agreement with the data for outflow models with conical and lemniscate (or hourglass) geometry. We calculate a mass outflow rate of 1.9(-1)(+2-) M-circle dot yr(-1) but a power for the outflow of only 0.08 per cent L-Bol. The molecular (H-2) gas kinematics is completely distinct from that of [Fe II] and Br gamma, showing radial expansion in an off-centred similar to 100 pc radius ring in the galaxy plane. The expansion velocity decelerates from approximate to 200 km s(-1) in the inner border of the ring to approximately zero at the outer border where our previous studies found a 10 Myr stellar population.