Dust beyond the torus: Revealing the mid-infrared heart of local Seyfert ESO 428-G14 with JWST/MIRI

Dust beyond the torus: Revealing the mid-infrared heart of local Seyfert ESO 428-G14 with JWST/MIRI
Houda Haidar, David J. Rosario, Almudena Alonso-Herrero, Miguel Pereira-Santaella, Ismael Garc’ia-Bernete, Stephanie Campbell, Sebastian F. H"onig, Cristina Ramos Almeida, Erin Hicks, Daniel Delaney, Richard Davies, Claudio Ricci, Chris M. Harrison, Mason Leist, Enrique Lopez-Rodriguez, Santiago Garcia-Burillo, Lulu Zhang, Chris Packham, Poshak Gandhi, Anelise Audibert, Enrica Bellocchi, Peter Boorman, Andrew Bunker, Franc{c}oise Combes, Tanio Diaz Santos, Fergus R. Donnan, Omaira Gonzalez Martin, Laura Hermosa Mu~noz, Matthaios Charidis, Alvaro Labiano, Nancy A. Levenson, Daniel May, Dimitra Rigopoulou, Alberto Rodriguez Ardila, T. Taro Shimizu, Marko Stalevski, Martin Ward
arXiv:2404.16100v1 Announce Type: new
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 main driver. However, little is known about its characteristics, spatial extent, or connection to the larger scale outflows. We present the first JWST/MIRI study aimed at imaging polar dust by zooming onto the heart of ESO 428-G14, part of the 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 with a radio jet and lies perpendicular to a molecular gas lane that feeds and obscures the nucleus. The morphology of the MIR structure bears a striking resemblance 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 contamination within the JWST filter bands from strong emission lines. Correcting for the contamination using ancillary spectroscopy, we find the morphology of the dust continuum to be asymmetric around the nucleus and more compact, though still clearly extended out to r ~ 100 pc. We estimate a temperature of the emitting dust of ~ 120 K. Using simple models, we find that the heating of small dust grains (~ 0.01 microns) by the radiation from the central AGN and/or radiative jet-induced shocks is responsible for the extended MIR emission. Large-grained dust, predicted by models of radiation-driven dusty winds from the torus, is unlikely to be important. This has important implications for scales to which AGN winds can carry dust and dense gas out into their host galaxies.arXiv:2404.16100v1 Announce Type: new
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 main driver. However, little is known about its characteristics, spatial extent, or connection to the larger scale outflows. We present the first JWST/MIRI study aimed at imaging polar dust by zooming onto the heart of ESO 428-G14, part of the 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 with a radio jet and lies perpendicular to a molecular gas lane that feeds and obscures the nucleus. The morphology of the MIR structure bears a striking resemblance 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 contamination within the JWST filter bands from strong emission lines. Correcting for the contamination using ancillary spectroscopy, we find the morphology of the dust continuum to be asymmetric around the nucleus and more compact, though still clearly extended out to r ~ 100 pc. We estimate a temperature of the emitting dust of ~ 120 K. Using simple models, we find that the heating of small dust grains (~ 0.01 microns) by the radiation from the central AGN and/or radiative jet-induced shocks is responsible for the extended MIR emission. Large-grained dust, predicted by models of radiation-driven dusty winds from the torus, is unlikely to be important. This has important implications for scales to which AGN winds can carry dust and dense gas out into their host galaxies.