23 September 2022
Title: A high angular resolution view of the PAH emission in Seyfert galaxies using the James Webb Space Telescope
The next International AGN seminar will be next Tuesday, September 27th at noon ET. Our speaker will be Ismael García-Bernete. Ismael is Postdoctoral Research Scientist at Oxford research interests are in the broad field of galaxy formation and evolution, particularly in understanding the role that the active galactic nuclei (AGN) play on galaxy evolution and feeding/feedback processes. Over the past few years, he has been focusing on high resolution sub-mm and integral field IR data to study AGNs and their connection to star formation and will be speaking to us on Webb results on what Webb has shown us about PAH emission in nearby Seyferts.
In this talk, I will summarize our first results on the PAH properties of AGN using new James Webb Space Telescope data. In this work, we used JWST/MIRI MRS spectroscopy of 3 Seyferts to compare their nuclear PAH emission with that of star-forming regions. Our results showed that a suite of PAH features is present in the innermost parts of luminous Seyfert galaxies. We found that the nuclear regions of AGN lie at different positions of the PAH diagnostic diagrams, whereas the SF regions are concentrated around the average values of SF galaxies. The nuclear PAH emission mainly originates in neutral PAHs. In contrast, PAH emission originating in the SF regions favors small ionized PAH grains. Therefore, our results provide evidence that the AGN have a significant impact on the ionization state and size of the PAH grains on scales of ~142-245 pc.
More information on the International AGN Seminar Series and meeting connection information can be found at the link below:
Meeting ID: 990 8953 7063
International AGN Seminar:br> https://bgc.physics.gmu.edu/international-agn-seminar-series/
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