2025ApJ...993..153F

We present James Webb Space Telescope (JWST) Near-Infrared Camera imaging of the nearby Seyfert 1.9 galaxy NGC 4258, which hosts strong star formation regions as well as an anomalous jet-like radio structure that extends through a significant portion of its disk. This galaxy provides a unique environment to study active galactic nucleus (AGN)-driven shocks and their impacts on the interstellar medium (ISM), as its proximity allows for narrow-band observations of various near-infrared tracers sensitive to multiple levels of shock and radiative excitation: [Fe II] (1.64 μm), Paα (1.87 μm), H₂ (2.21 μm), 3.3 μm polycyclic aromatic hydrocarbon (PAH) emission, Brα (4.05 μm), and Pfβ (4.66 μm), allowing us to trace shocks with parsec-scale resolution. Comparing these near-infrared observations with available ultraviolet, optical, radio, and X-ray imaging, we find that shocks present in the brightest regions of the anomalous radio structure are likely of low velocity (50-100 km s^–1), suggesting that these features originate from AGN-driven winds that interact with the host medium and mechanically impart energy into the disk. Further, while the cospatial [Fe II] and H₂ emissions indicate multiphase shocks, PAH emission is relatively weaker in or absent from the most shock-excited regions, consistent with the destruction of small dust grains. Finally, we propose that surveys identifying enhanced [Fe II] in AGN host galaxies may systematically reveal a key population, where AGN feedback is significantly coupled with the surrounding ISM and actively shaping galaxy evolution.