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Arxiv: Dust beyond the torus: Revealing the mid-infrared heart of local Seyfert ESO 428-G14 with JWST/MIRI Published: 4/24/2024 9:00:02 PM Updated: 4/24/2024 9:00:02 PM

Paper abstract: Polar dust has been discovered in a number of local Active Galactic Nuclei(AGN), with radiation-driven torus models predicting a wind to be its maindriver. However, little is known about its characteristics, spatial extent, orconnection to the larger scale outflows. We present the first JWST/MIRI studyaimed at imaging polar dust by zooming onto the heart of ESO 428-G14, part ofthe GATOS survey of local AGN. We clearly detect extended mid-infrared (MIR)emission within 200 pc from the nucleus. This polar structure is co-linear witha radio jet and lies perpendicular to a molecular gas lane that feeds andobscures the nucleus. The morphology of the MIR structure bears a strikingresemblance to that of gas ionised by the AGN in the narrow-line region (NLR).We demonstrate that part of this spatial correspondence is due to contaminationwithin the JWST filter bands from strong emission lines. Correcting for thecontamination using ancillary spectroscopy, we find the morphology of the dustcontinuum to be asymmetric around the nucleus and more compact, though stillclearly extended out to r ~ 100 pc. We estimate a temperature of the emittingdust of ~ 120 K. Using simple models, we find that the heating of small dustgrains (~ 0.01 microns) by the radiation from the central AGN and/or radiativejet-induced shocks is responsible for the extended MIR emission. Large-graineddust, predicted by models of radiation-driven dusty winds from the torus, isunlikely to be important. This has important implications for scales to whichAGN winds can carry dust and dense gas out into their host galaxies.