Outflowing shocked gas dominates the NIR H₂ emission from the dual AGN NGC 6240

We present a multi-line study of the kinematics of the molecular and ionised gas phases in the central ∼ 2 kpc of the luminous infrared galaxy and dual active galactic nucleus (AGN) NGC 6240, based on archival JWST/NIRSpec and ALMA observations. Since a primary goal of our analysis is to study outflows, we devised a new spectral-line fitting approach to de-blend rotating and non-rotating gas components in the observed near-infrared (NIR) emission lines. Our method is more physically motivated than previous approaches and better tailored to the extreme feedback mechanisms at work in NGC 6240. We find that sim65% of the Paα, H₂, and FeII line fluxes within the NIRSpec field of view arise from gas components that are kinematically decoupled from the stars. In particular, the NIR H₂ lines show the most deviation from the stars, with peak emission between the two rotating stellar structures. The polycyclic aromatic hydrocarbon (PAH) emission feature at 3. 3 μm does not follow the NIR H₂ morphology, indicating that the latter does not trace photon-dominated regions. In the non-rotating gas components, we identified a bi-conical wind that launched from the northern AGN, expanding along the minor axis of stellar rotation. This wind is dominated by ionised gas and, although it entrains some H₂ gas, it does not show a H₂/PAH enhancement, suggesting either high UV irradiation or expansion along a relatively gas-free path. Furthermore, we find bright non-rotating gas emission between the two AGNs and around the southern AGN, which we interpret as due to an outflow that launched from the southern nucleus, coinciding with the massive molecular outflow previously studied in cold (sub-) millimetre tracers. The strong H₂/PAH enhancement measured in this region, coextensive with high velocity redshifted gas (v), suggests that the shocks responsible for the high H₂/PAH ratios are due to the outflow rather than to the collision of media during the merger. Our results show that most of the NIR line emission in NGC 6240 is decoupled from the stars, and that most of the warm H₂ is shock-excited and embedded in a powerful outflow, where it coexists with colder molecular gas. km s -1