Outflowing shocked gas dominates the NIR H${}_2$ emission from the dual AGN NGC6240

Abstract

[Abridged] We present a multi-line study of the kinematics of the molecular and ionised gas phases in the central 2 kpc of NGC6240, based on JWST/NIRSpec and ALMA observations. We devised a new spectral-line fitting approach to de-blend rotating and non-rotating gas components, which is better tailored to the extreme feedback mechanisms at work in NGC6240. We find that ~65% of the Pa$\alpha$, H${}_2$, and [FeII] line fluxes within the NIRSpec field of view arise from gas components that are kinematically decoupled from the stars. The NIR H${}_2$ lines show the most deviation from the stars, with peak emission between the two rotating stellar structures. The PAH 3.3$\mu$m feature does not follow the NIR H${}_2$ morphology, indicating that the latter does not trace PDRs. In the non-rotating gas components, we identify a biconical wind 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 H${}_2$, it does not show a H${}_2$/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 AGN and around the southern AGN, which we interpret as due to an outflow launched from the southern nucleus, coinciding with the molecular outflow previously studied in cold (sub-)millimeter tracers. The strong H${}_2$/PAH enhancement measured in this region, coextensive with high velocity redshifted gas ($v\sim 900$ km s${}^{-1}$), suggests that the shocks responsible for the high H${}_2$/PAH ratios are due to the outflow rather than to the collision of media during the merger. Our results show that the bulk of the NIR line emission in NGC6240 is decoupled from the stars, and that most of the warm H${}_2$ is shock-excited and embedded in a powerful outflow, where it coexists with colder molecular gas.

Accepted for publication in A&A

References in corpus (26)

• Improving the full spectrum fitting method: accurate convolution with Gauss-Hermite functions
• The second data release from the European Pulsar Timing Array III. Search for gravitational wave signals
• The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope I. Overview of the instrument and its capabilities
• Massive molecular outflows and negative feedback in ULIRGs observed by Herschel-PACS
• UV-extended E-MILES stellar population models: young components in massive early-type galaxies
• Supermassive black hole binaries in gaseous and stellar circumnuclear discs: orbital dynamics and gas accretion
• Properties of the Multiphase Outflows in Local (Ultra)luminous Infrared Galaxies
• ALMA Imaging of HCN, CS and dust in Arp 220 and NGC 6240
• The ultra-dense, interacting environment of a dual AGN at z $\sim$ 3.3 revealed by JWST/NIRSpec IFS
• The full infrared spectrum of molecular hydrogen
• A hard X-ray view of Luminous and Ultra-luminous Infrared Galaxies in GOALS: I - AGN obscuration along the merger sequence
• Fast cold gas in hot AGN outflows
• Star formation and nuclear activity in luminous infrared galaxies: An infrared through radio review
• NGC6240: A triple nucleus system in the advanced or final state of merging
• CO excitation, molecular gas density and interstellar radiation field in local and high-redshift galaxies
• Searching for Dual AGN in Galaxies with Double-Peaked Emission Line Spectra using Radio Observations
• Physics of ULIRGs with MUSE and ALMA: PUMA IV. No tight relation between cold molecular outflow rates and AGN luminosities
• The Molecular Gas in the NGC 6240 Merging Galaxy System at the Highest Spatial Resolution
• Enhanced UV radiation and dense clumps in Mrk231's molecular outflow
• MICONIC: Dual active galactic nuclei, star formation, and ionised gas outflows in NGC 6240 seen with MIRI/JWST
• Revisiting the complex nuclear region of NGC 6240 with Chandra
• The Role of AGN in Luminous Infrared Galaxies from the Multiwavelength Perspective
• How to Fuel an AGN: Mapping Circumnuclear Gas in NGC 6240 with ALMA
• The JWST/NIRSpec view of the nuclear region in the prototypical merging galaxy NGC 6240
• A possible relation between global CO excitation and massive molecular outflows in local ULIRGs
• Massive dusty multiphase outflow in local merger shows no sign of slowing on kiloparsec scales

Cited by in corpus (1)

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