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Arxiv: The Galaxy Activity, Torus, and Outflow Survey (GATOS). V: Unveiling PAH survival and resilience in the circumnuclear regions of AGN with JWST Published: 9/9/2024 6:00:13 PM Updated: 9/9/2024 6:00:13 PM

Paper abstract: We analyze JWST MIRI/MRS observations of the infrared PAH bands in thenuclear and circumnuclear regions of local AGN from the GATOS Survey. In thiswork, we examine the PAH properties in the circumnuclear regions of AGN andAGN-outflows, and compare them to those in star-forming regions and theinnermost regions of AGN. This study employs 4.9-28.1 micron sub-arcsecondangular resolution data to investigate the properties of PAH in three nearbysources (DL~30-40 Mpc). Our findings align with previous JWST studies, showingthat the central regions of AGN show a larger fraction of neutral PAH molecules(i.e. elevated 11.3/6.2 and 11.3/7.7 PAH ratios) compared to star-forminggalaxies. We find that the AGN might affect not only the PAH population in theinnermost region but also in the extended regions up to ~kpc scales. Bycomparing our observations to PAH diagnostic diagrams, we find that, ingeneral, regions located in the projected direction of the AGN-outflow occupysimilar positions on the PAH diagnostic diagrams as those of the innermostregions of AGN. Star-forming regions that are not affected by the AGN in thesegalaxies share the same part of the diagram as Star-forming galaxies. Weexamine the potential of the PAH-H2 diagram to disentangle AGN versusstar-forming activity. Our results suggest that in Sy-like AGN, illuminationand feedback from the AGN might affect the PAH population at nuclear and kpcscales, in particular, the ionization state of the PAH grains. However, PAHsizes are rather similar. The carriers of the ionized PAH bands (6.2 and 7.7micron) are less resilience than those of neutral PAH bands (11.3 micron),which might be particularly important for strongly AGN-host coupled systems.Therefore, caution must be applied when using PAH bands as star-formation rateindicators in these systems even at kpc scales, with the ionized ones beingmore affected by the AGN.