Galaxy formation and evolution

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.

Abstract:

Merging luminous galaxies are ideal laboratories for studying some of the most extreme astrophysical phenomena. The local (z=0.1232) obscured quasar J1356+1026 has two nuclei, North and South (J1356N and J1356S), but despite numerous efforts, J1356S had not yet been confirmed as an AGN . Based on the superb sensitivity and spatial resolution of the MIRI/MRS instrument on board the JWST, we present new evidence suggesting that J1356S may indeed host an AGN with ̊m log L_ ̊m bol =43.4±^ 0.6 _ 0.5 erg s^ -1 . This is supported by the detection of strong coronal line emission at this location and by a spectral shape that differs from that of J1356N and those of the narrow-line region. Aided by the spatially resolved information of MIRI/MRS and VLT/SINFONI, we also found that the high-ionization gas, traced by the coronal lines Ne v 14.3 μm and Si vi 1.963 μm, extends from sim13-15.5 kpc. This is likely a lower limit of the true extension, as suggested by the comparison with optical imaging from HST. The extended Ne v emission can be accounted for by photoionization from the quasar in J1356N in a relatively low-density environment, ranging from ̊m n_ełeq 2000-3800 cm^ -3 in J1356N and ̊m n_ełeq 600-1200 cm^ -3 in J1356S and the narrow-line region, as measured from the Ne v 14.3 μm and 24.3 μm lines.