A Spatially Resolved H i Survey of Seyfert Galaxies: The Role of Active Galactic Nucleus Feedback in Shaping Atomic Gas Reservoirs

Résumé fourni par la source

Abstract Active galactic nucleus (AGN) feedback is a key ingredient in galaxy evolution, yet its impact on the cold atomic gas reservoir—the neutral hydrogen (H i ) phase—remains poorly constrained. We present the most extensive spatially resolved H i 21 cm survey of Seyfert AGN hosts to date, based on observations with the Giant Metrewave Radio Telescope (GMRT). We measure H i masses and sizes for eight Seyfert galaxies, and map the detailed kinematics and surface densities for two representative targets. We find that AGN-host galaxies exhibit a slightly shallower H i mass–size relation than the canonical relation or the S imba simulation predictions; however, the measured slope remains consistent with the canonical value within 2 σ uncertainties. This result suggests that AGN feedback does not significantly disrupt the global extent or large-scale structure of atomic gas reservoirs. To investigate the internal H i kinematics in greater detail, we perform a 3D kinematic forward modeling of the H i disk in UGC 4503. Our analysis reveals an elevated intrinsic velocity dispersion of σ = 14 . 9 − 3.8 + 6.1 km s −1 and a reduced level of rotational support, with V / σ = 14.2 8 − 4.17 + 4.97 , compared to large-sample star-forming spirals. These kinematic signatures, together with localized residuals in the velocity field, indicate that AGN-driven outflows or jets may inject or indirectly affect the turbulence in the atomic gas disk, potentially regulating the cold gas reservoir. Future GMRT observations, combined with optical integral-field spectroscopy from Mapping Nearby Galaxies at Apache Point Observatory, will enable quantitative constraints on the role of AGN feedback in regulating star formation efficiency across a larger and more representative galaxy sample.

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