Examinando por Autor "Delaney, Daniel"

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Acceso Abierto
GATOS – XI. Excess dust heating in the narrow-line regions of nearby AGN revealed with JWST/MIRI
(Blackwell Publishing, 2026-01-26) Haidar, Houda; Rosario, David J.; García Bernete, Ismael; Alonso-Herrero, Almudena; Audibert, Anelise; Campbell, Steph; Harrison, Chris; Costa, Tiago; Hermosa Muñoz, Laura; Combes, Francoise; Rigopoulou, Dimitra; Ricci, Claudio; Ramos Almeida, Cristina; Bellocchi, Enrica; Boorman, Peter; Bunker, Andrew; Davies, Richard; Delaney, Daniel; Díaz Santos, Tanio; Esposito, Federico; Fawcett, Victoria; Gandhi, Poshak; García-Burillo, Santiago; González Martín, Omaira; Hicks, Erin K. S.; Hönig, Sebastian; Labiano, Alvaro; Levenson, Nancy A.; Lopez-Rodriguez, Enrique; Packham, Christopher; Pereira Santaella, Miguel; Riffel, Rogemar A.; Rodríguez Ardila, Alberto; Schneider, John; Thomas Shimizu, Taro; Stalevski, Marko ; Villar Martín, Montserrat; Ward, Martin J.; Zhang, Lulu; Leeds, Gillian; Donnan, Fergus; European Commission (EC); Comunidad de Madrid; Ministerio de Ciencia e Innovación (MICINN); Swiss National Science Foundation (SNSF); Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT); Ministry of Education, Science and Technological Development of the Republic of Serbia; Agencia Estatal de Investigación (AEI); European Research Council (ERC); UK Research and Innovation (UKRI); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Foundation of Rio Grande do Sul State for Research Support (FAPERGS)
We present James Webb Space Telescope/Mid-Infrared Instrument imaging of eight nearby active galactic nuclei (AGN) from the GATOS (Galactic Activity, Torus, and Outflow Survey) survey to investigate the physical conditions of extended dust in their narrow-line regions (NLRs). In four galaxies (ESO 428–G14, NGC 4388, NGC 3081, and NGC 5728), we detect spatially resolved dust structures extending ∼100–200 pc along the NLR. In these systems, we find a strong link between the morphology of the dust, the radio ejecta, and the coronal [Sivi] emission, implying that dust carries imprints of the processes shaping the NLR. Using spatially resolved spectral energy distributions, we show that dust in the NLR has systematically steeper slopes than star-forming clumps. This dust emits at temperatures in the range $150 \text{-} 220\, \rm K$, at a distance of ∼150 pc from the nucleus. Using simple models, we show that, even under optimistic assumptions of grain size and AGN luminosity, the excess mid-infrared emission cannot be explained by AGN illumination alone. We interpret this excess heating as in situ. We show that shocks with velocities v ∼ 200 - 400 km s in dense gas can close this gap, and in some cases even account for the total observed emission. This, combined with multiple lines of evidence for shocks in these regions, supports a scenario in which shocks not only coexist with dust but may be playing a key role in heating it. Our findings reveal shocks may be an important and previously overlooked driver of extended dust emission in the central hundreds of parsecs in AGN.
Acceso Abierto
GATOS: Distinct Feedback Modes in AGN Central Regions Revealed by Spatially Resolved JWST Spectroscopy
(IOP Publishing, 2026-08-20) Zhang, Lulu; Packham, Christopher; Hicks, Erin K. S.; García Bernete, Ismael; Alonso-Herrero, Almudena; Davies, R. I.; Ward, Martin J.; Delaney, Daniel; Izumi, Takuma; Rigopoulou, Dimitra; Ramos Almeida, Cristina; González Martín, Omaira; Riffel, Rogemar A.; Ricci, Claudio; Villar Martín, Montserrat; Combes, Francoise; Pereira Santaella, Miguel; Hönig, Sebastian; Bunker, Andrew; Boorman, Peter; Bellocchi, Enrica; Levenson, Nancy A.; García-Burillo, Santiago; Donnan, Fergus; Audibert, Anelise; Fuller, Lindsay; Díaz Santos, Tanio; Rosario, David J.; Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Agencia Estatal de Investigación (AEI); National Aeronautics and Space Administration (NASA); Space Telescope Science Institute (STScI); Comunidad de Madrid; European Commission (EC); Universidad Nacional Autónoma de México (UNAM)
This Letter presents JWST MIRI/Medium-Resolution Spectrometer (MRS) observations of the central r ≈ 40–240 pc regions of five active galactic nuclei (AGN) spanning a wide range of luminosities (log Lbol/erg s−1 ≈ 39.8–43.8). Combining multiphase diagnostics from polycyclic aromatic hydrocarbons (PAHs), molecular hydrogen (H2), and ionized gas at spatial scales of ∼4–24 pc, this study presents a spatially resolved investigation into the effects of the two distinct AGN feedback modes—radiative and kinetic—on the surrounding medium. The results indicate that these two feedback modes, associated with AGN irradiation and shock processing, respectively, collectively drive the relative suppression of PAH emission in the nuclear regions of the targets studied here. Moreover, the coexistence of these two AGN feedback modes, especially the shock processing associated with either jets or outflows, in the central regions of AGN naturally explains both the bimodal distribution of PAH band ratios observed in the targets studied here and the seemingly disparate results reported in the literature. Although based on a limited sample, these findings provide new insights into calibrating star formation rates from PAH emission in AGN and, more importantly, lay the groundwork for a practical framework to diagnose and quantify AGN feedback in the JWST era.
Acceso Abierto
The Galaxy Activity, Torus, and Outflow Survey (GATOS) V. Unveiling PAH survival and resilience in the circumnuclear regions of AGNs with JWST
(EDP Sciences, 2024-09-09) García Bernete, Ismael; Rigopoulou, Dimitra; Donnan, Fergus; Alonso-Herrero, Almudena; Pereira Santaella, Miguel; Shimizu, Thomas Taro; Davies, Richard; Roche, P. F.; García-Burillo, Santiago; Labiano, Alvaro; Hermosa Muñoz, Laura; Zhang, Lulu; Audibert, Anelise; Bellocchi, Enrica; Bunker, Andrew; Combes, Francoise; Delaney, Daniel; Esparza Arredondo, Donaji; Gandhi, P.; González Martín, Omaira; Hönig, Sebastian; Imanishi, Masatoshi; Hicks, Erin K. S.; Fuller, Lindsay; Leist, Mason Tanner; Levenson, Nancy A.; López Rodríguez, Enrique; Packham, Christopher; Ramos Almeida, Cristina; Ricci, Claudio; Stalevski, Marko; Villar Martín, Montserrat; Ward, Martin J.; Science and Technology Facilities Council (STFC); Comunidad de Madrid; European Commission (EC); European Space Agency (ESA); Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT); Ministerio de Ciencia e Innovación (MICINN); National Aeronautics and Space Administration (NASA); Space Telescope Science Institute (STScI); Universidad Nacional Autónoma de México (UNAM)
This study analyses JWST MIRI/MRS observations of the infrared (IR) polycyclic aromatic hydrocarbon (PAH) bands in the nuclear (∼0.4″ at 11 μm; ∼75 pc) and circumnuclear regions (inner ∼kpc) of local active galactic nuclei (AGNs) from the Galactic Activity, Torus, and Outflow Survey (GATOS). We examine the PAH properties in the circumnuclear regions of AGNs and the projected direction of AGN-outflows and compare them to those in star-forming regions and the innermost regions of AGNs. This study employs 4.9–28.1 μm sub-arcsecond angular resolution data to investigate the properties of PAHs in three nearby sources (DL ∼ 30 − 40 Mpc). Our findings are aligned with previous JWST studies, demonstrating that the central regions of AGNs display a larger fraction of neutral PAH molecules (i.e. elevated 11.3/6.2 and 11.3/7.7 μm PAH ratios) in comparison to star-forming galaxies. We find that AGNs might affect not only the PAH population in the innermost region, but also in the extended regions up to ∼kpc scales. By comparing our observations to PAH diagnostic diagrams, we find that, in general, regions located in the projected direction of the AGN-outflow occupy similar positions on the PAH diagnostic diagrams as those of the innermost regions of AGNs. Star-forming regions that are not affected by the AGNs in these galaxies share the same part of the diagram as star-forming galaxies. We also examined the potential of the PAH-H2 diagram to disentangle AGN-versus-star-forming activity. Our results suggest that in Seyfert-like AGNs, the illumination and feedback from the AGN might affect the PAH population at nuclear and kpc scales, particularly with respect to the ionisation state of the PAH grains. However, PAH molecular sizes are rather similar. The carriers of the ionised PAH bands (6.2 and 7.7 μm) are less resilient than those of neutral PAH bands (11.3 μm), which might be particularly important for strongly AGN-host coupled systems. Therefore, caution must be applied when using PAH bands as star-formation rate indicators in these systems even at kpc scales, with the effects of the AGN being more important for ionised ones.