Mon. Not. R. Astron. Soc., 445, 2353-2370 (2014/December-2)
Modelling the [FeII] λ1.644 µm outflow and comparison with H2 and H+ kinematics in the inner 200 pc of NGC 1068.
BARBOSA F.K.B., STORCHI-BERGMANN T., McGREGOR P., VALE T.B. and ROGEMAR RIFFEL A.
Abstract (from CDS):
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 ≅8 pc and spectral resolution ∼ 5300 in the emission lines [Feii] λ1.644µm, H2λ2.122µm and Brγ. The [Feii] emission line provides a better coverage of the NLR outflow than the previously used [Oiii] λ5007 emission line, extending beyond the area of the bipolar cone observed in Brγ and [Oiii]. 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 [Feii] 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^+2_-1 M☉/yr but a power for the outflow of only 0.08 per cent LBol. The molecular (H2) gas kinematics is completely distinct from that of [Feii] and Brγ, showing radial expansion in an off-centred ∼ 100 pc radius ring in the galaxy plane. The expansion velocity decelerates from ~200 km/s in the inner border of the ring to approximately zero at the outer border where our previous studies found a 10 Myr stellar population.