Miguel Pereira Santaella

Abstract:

We present new James Webb Space Telescope Mid-Infrared Instrument Medium-Resolution Spectrometer observations of the nearby ultraluminous infrared galaxy F10565+2448. These integral field spectroscopic data reveal an unresolved nuclear outflow in both warm-ionized and warm-molecular gas phases as well as a resolved blueshifted kiloparsec-scale warm-molecular outflow. The unresolved warm-ionized outflow has a mean projected velocity up to −520 km s−1, while the unresolved warm-molecular outflow is slower at −150 km s−1. For the resolved warm-molecular outflow, the projected mean velocity (−280 < v50 < −110 km s−1) is only slightly faster than the velocity of the disk (−70 < v50 < 120 km s−1) and, as such, likely does not exceed the estimated escape velocity of ≳300 km s−1. The warm-molecular outflow is slightly hotter (507 ± 25 K) than the disk (329 ± 5 K), and displays areas of higher temperature and lower column density that may indicate a shock front, which we explore using the [Fe II] 5.34 μm/Pfα shock diagnostic. Analysis of the polycyclic aromatic hydrocarbon features reveals trends of ionization and grain size that first decrease with radius up to 1 kpc before increasing up to 3 kpc. These results bolster the picture of F10565+2448 being an active galactic nucleus (AGN)-starburst composite where both star formation and AGN-powered phenomena are required to explain the outflow energetics.

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 study of nuclear outflows in the nearby dwarf Seyfert galaxy NGC 4395, which hosts an intermediate-mass black hole. Using JWST/NIRSpec and MIRI integral-field-unit spectroscopy (1.66–28.6 μm), together with Atacama Large Millimeter/submillimeter Array (ALMA) and Gemini/GMOS data, we probe the ionized and molecular gas on parsec scales. The JWST nuclear spectra reveal 134 emission lines, including H i, He, numerous fine-structure lines, H2 rotational/rovibrational transitions, and several polycyclic aromatic hydrocarbon bands. Modelling of the H2 rotational lines reveals three warm/hot molecular components (T ≈ 580, 1480, and 2900 K), along with a cold (< 50 K) phase traced by ALMA CO(2–1). Outflow signatures are detected in cold and warm/hot molecular gas, in H i, and in 36 fine-structure lines spanning ionization potentials of 7.6–300 eV. Ionized outflow velocities range from 127 to 716 km s⁻¹, with blueshifted and redshifted components consistent with a stratified biconical geometry. The cold molecular gas shows a mass outflow rate nearly 1–2 orders of magnitude larger than that of the warm/hot molecular and ionized phases. The kinetic coupling efficiency is 0.003%–0.12% for the coronal-line gas and 0.4%–1.4% for the H i outflow, indicating that only the low-ionization gas significantly impacts the surrounding ISM. Outflow velocity and the fraction of flux in the outflowing component increase with ionization potential, implying that the most highly ionized gas originates closest to the active galactic nucleus and is most efficiently accelerated.

Abstract:

We utilize James Webb Space Telescope (JWST) Mid Infrared Instrument (MIRI) integral field unit observations to investigate the behavior and excitation of H2 in the nearby Seyfert galaxies NGC 3081 and NGC 5506, both part of the Galactic Activity, Torus, and Outflow Survey (or GATOS). We compare population levels of the S(1) to S(8) rotational H2 emission lines visible to JWST/MIRI spectroscopy to models assuming local thermodynamic equilibrium (LTE), in order to estimate the column density and thermal scaling of the molecular gas. For the nuclear regions, we incorporate Very Large Telescope Spectrograph for INtegral Field Observations in the Near Infrared (or VLT/SINFONI) K-band observations to estimate population levels for available rovibrational H2 emission lines, and compare the resultant population curves to non-LTE radiative transfer models and shock modeling. We report a differing set of prominent active galactic nuclei (AGN)-driven excitation mechanisms between the two galaxies. For NGC 3081, we find that a non-LTE radiative transfer environment is adequate to explain observations of the nuclear region, indicating that the primary mode in which the AGN transfers excitation energy is likely irradiation. We estimate the extent of AGN photoionization along the ionization bicone to be ≈330 pc. In contrast, for NGC 5506, we find a shock scenario to be a more plausible excitation mechanism, a conclusion bolstered by an observed spatial correlation between higher-energy rotational H2 and [Fe II]5.34μm emission. In addition, we identify potential nuclear H2 outflows resulting from an interaction between the ionization bicone and the rotational disk. By isolating the outflowing component of the H2 emission, we estimate the warm molecular mass outflow rate to be 0.07 M⊙ yr−1.

Abstract:

We present a 19.7–214 μm imaging atlas of local (4–181 Mpc; median 43 Mpc) active galactic nuclei (AGN) observed with FORCAST and HAWC+ on board the SOFIA telescope with angular resolutions ~3″–20″. This atlas comprises 22 Seyferts (17 Type 2 and five Type 1) with a total of 69 images, 41 of which have not been previously published. The AGN span a range of luminosities of log10(Lbol[ergs-1])=[42, 46] with a median of log10(Lbol[ergs−1])=44.1±1.0 . We provide the total fluxes of our sample using aperture photometry for point-source objects and a 2D Gaussian fitting for objects with extended host galaxy emission, which was used to estimate the unresolved nuclear component. Most galaxies in our sample are pointlike sources; however, four sources (Centaurus A, Circinus, NGC 1068, and NGC 4388) show extended emission in all wavelengths. The 30–40 μm extended emission in NGC 4388 is coincident with the narrow-line region at PA ~ 50°, while the dusty extension at longer wavelengths arises from the host galaxy at PA ~ 90°. Our new observations allow us to construct the best-sampled parsec-scales (spectral energy distributions, SEDs) available between 30 and 500 μm for a sample of nearby AGN. We estimate that the average peak wavelength of the nuclear SEDs is ~40 μm in νFν, which we associate with an unresolved extended dusty region heated by the AGN.