JWST/MIRI Detection of [Ne v] and [Ne vi ] in M83: Evidence for the Long Sought-after Active Galactic Nucleus?
Year: 2025
Type: article
Abstract: We report the first detections of [Ne v] λ14.3 μm and [Ne vi] λ7.7 μm at high confidence (S/N ≥ 6) in the nuclear region of the nearby spiral galaxy M83. Emission-line maps of these high-ionization lines show several compact structures. Specifically, the [Ne vi] emission is located at 140 pc from the optical nucleus and appears as a point source of size ≲18 pc (FWHM ≲ 0 . ″ 8). We investigate the possible source of this extreme emission through comparison with photoionization models and ancillary data. We find that photoionization models of fast radiative shocks are able to reproduce the observed high-excitation emission-line fluxes only for the lowest preshock density available in the library, n = 0.01 cm−3. Additionally, tailored active galactic nucleus (AGN) photoionization models assuming a two-zone structure are compatible with the observed high-ionization fluxes. Our simple AGN model shows that the emission at the location of the [Ne vi] source can be the result of a cloud being ionized by the radiation cone of an AGN. We stress, however, that to definitively confirm an AGN as the main source of the observed emission, more complex modeling accounting for different geometries is required. Previously known as a purely starburst system, these new findings of the nuclear region of M83 will require a reassessment of its nature and of objects similar to it, particularly now that we have access to the unparalleled infrared sensitivity and spatial resolution of the James Webb Space Telescope.
Source: The Astrophysical Journal
Authors: Svea Hernandez, Linda J. Smith, Logan H. Jones, Aditya Togi, Marcio B. Meléndez, Valentina Abril-Melgarejo, Angela Adamo, Almudena Alonso Herrero, Tanio Díaz-Santos, Travis C. Fischer, Santiago García-Burillo, Alec S. Hirschauer, Leslie K. Hunt, Bethan James, Vianney Lebouteiller, Knox S. Long, Matilde Mingozzi, Lise Ramambason, Cristina Ramos Almeida
Institutions: Space Telescope Science Institute, Texas State University, Stockholm University, AlbaNova, Consejo Superior de Investigaciones Científicas, Centro de Astrobiología, European University Cyprus, FORTH Institute of Astrophysics, Foundation for Research and Technology Hellas, Spanish National Observatory, Arcetri Astrophysical Observatory, Centre National de la Recherche Scientifique, Université Paris Cité, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, Astrophysique, Instrumentation et Modélisation, Eureka Scientific, Heidelberg University, Universidad de La Laguna, Instituto de Astrofísica de Canarias
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Aeronautics and Space Administration, Space Telescope Science Institute, Ministerio de Ciencia, Innovación y Universidades, European Space Agency, Deutsche Forschungsgemeinschaft, Hellenic Foundation for Research and Innovation, European Regional Development Fund, Agencia Estatal de Investigación
OpenAlex ID: W4409521991