Galaxy formation and evolution

Abstract:

We present a detailed study of the inner regions of NGC 7582, a nearby Seyfert 2 galaxy, from the Galaxy Activity, Torus, and Outflow Survey (GATOS). The galaxy hosts a circumnuclear star-forming disc and an active galactic nucleus (AGN)-driven biconical ionized outflow. Using James Webb Space Telescope Near-Infrared Spectrograph (NIRSpec) and Mid-Infrared Instrument/Medium-Resolution Spectrometer (MIRI/MRS) integral-field spectroscopy, we analyse ionic emission lines spanning a wide range of ionization potentials (IPs, –126 eV). Gaussian line-profile fitting reveals kinematic stratification: low-IP species ( eV; e.g. [Fe ii], [Ar ii], and [Ne ii]) trace ordered disc rotation with PA , while high-IP species ( eV; e.g. [O iv], [Mg iv], and [Ne v]) follow the outflow with PA . Outflowing gas exhibits systematically higher velocity dispersions ( km s−1) than the disc ( km s−1), consistent with turbulent or bulk motions. Intermediate-IP lines, [S iii], [Ar iii], and [Ne iii], show contributions from both components, with the outflow characterized by higher dispersion, lower amplitude, and higher velocities in double-Gaussian fits. For these lines, a thin inclined disc plus 1D outflow model enables robust separation and quantification of the disc and outflow velocity fields. The outflow is consistent with a hollow bicone capable of accelerating gas beyond the local escape velocity, implying most material is unlikely to be re-accreted. The ionization cone opening angle shows no dependence on IP, indicating the AGN torus polar regions are largely unobscured. Our study provides new insights into AGN-driven outflows and circumnuclear disc dynamics, offering a framework to disentangle overlapping interstellar medium kinematics in nearby active galaxies.

Abstract:

We utilize James Webb Space Telescope/Mid Infrared Instrument (JWST/MIRI) Integral Field Unit observations from the Galaxy Activity, Torus and Outflow Survey to investigate the diverse range of ionized outflow rates of obscured active galactic nuclei (AGN) with similar bolometric luminosity and explore potential associations with AGN feedback. We explore spatial correlations between ionized emission potentially associated with fast shocks ([Fe II]5.34μm) and the excitation of H2. We further constrain our investigation to the inner 400 pc (the nuclear and circumnuclear regions r < 200 pc), and estimate the excitation temperature and column density of H2 assuming local thermodynamic equilibrium and using the S(1)–S(8) rotational H2 emission lines visible to JWST/MIRI spectroscopy. We report the molecular gas temperature of the deprojected 400 pc nuclear region to correlate with the ionized mass outflow rate. We also observe a stronger degree of spatial correlation between [Fe II]5.34μm emission and H2 gas temperature. We observe regions of enhanced [Fe II]5.34μm/[Ar II]6.99μm spatially coincident with the ionization cones of objects with higher ionized outflow rates and [Fe II]5.34μm/[Ar II]6.99μm in the deprojected 400 pc nuclear region to scale positively with both the ionized outflow rate and the estimated molecular gas temperature. We do not observe the estimated jet cavity power within the central 400 pc as strongly correlated with the ionized mass outflow rate or molecular gas temperature of the nuclear region. We take the preceding observations to suggest a higher degree of interaction between AGN outflows and the circumnuclear disk.

Abstract:

We present a multiwavelength catalog of mid-infrared-selected compact sources in 19 nearby galaxies, combining JWST NIRCam/MIRI, Hubble Space Telescope UV–optical broadband, Hα narrowband, and Atacama Large Millimeter/submillimeter Array CO observations. We detect 24,945 compact sources at 21 μm and 55,581 at 10 μm. Artificial star tests show 50% completeness limits of ∼5 μJy for the 10 μm catalog, and ∼24 μJy for the 21 μm catalog. We find that 21 μm compact sources contribute ∼20% of the total galaxy emission in that band, but only contribute 5% at 10 μm. We classify sources using stellar evolution and population synthesis models combined with empirical classifications derived from the literature. Our classifications include Hα-bright and dust-embedded optically faint clusters, red supergiants, oxygen-rich and carbon-rich asymptotic giant branch stars, and a range of rarer stellar types. In sampling a broad range of star-forming environments with a uniform, well-characterized selection, this catalog enables analyses of infrared-bright stellar populations. We find that Hα-faint sources account for only 10% of dusty (likely young) clusters, implying that the infrared-bright, optically faint phase of cluster evolution is short compared to the Hα-bright stage. The luminosity functions of 10 and 21 μm sources follow power-law distributions, with the 21 μm slope (−1.7 ± 0.1) similar to that of giant molecular cloud mass functions and ultraviolet bright star-forming complexes, while the 10 μm slope (−2.0 ± 0.1) is closer to that of young stellar clusters.