GA-NIFS: Early-stage feedback in a heavily obscured AGN at $z=4.76$

Eleonora Parlanti , Stefano Carniani , Hannah Übler , Giacomo Venturi , Francesco d'Eugenio , Santiago Arribas , Andrew J Bunker , Stéphane Charlot (1) , Nora Lützgendorf (2) , Roberto Maiolino , Michele Perna , Bruno Rodríguez del Pino , Chris J Willott , Torsten Böker (2) , Alex J Cameron , Jacopo Chevallard , Chiara Circosta (2) , Giovanni Cresci , Gareth C Jones , Nimisha Kumari (2) , Isabella Lamperti , Jan Scholtz

1 IAP - Institut d'Astrophysique de Paris
2 ESA - Agence Spatiale Européenne = European Space Agency

Dust-obscured galaxies are thought to represent an early evolutionary phase of massive galaxies in which the active galactic nucleus (AGN) is still deeply buried in significant amounts of dusty material and its emission is strongly suppressed. The unprecedented sensitivity of the James Webb Space Telescope enables us for the first time to detect the rest-frame optical emission of heavily obscured AGN and unveil the properties of the hidden accreting super-massive black holes (BHs). In this work, we present the JWST/NIRSpec IFS data of ALESS073.1, a massive, dusty, star-forming galaxy at $z = 4.76$ hosting an AGN at its center. The detection of a very broad $H_\alpha$ emission associated with the Broad Line Region (BLR) confirms the presence of a BH ($\log(M_{BH}/M_\odot)>8.7$) accreting at less than 15% of its Eddington limit and classifies the target as a Type 1 AGN. The rest-frame optical emission lines also reveal a fast ionized gas outflow marginally resolved in the galaxy center. The high sensitivity of NIRSpec allows us to perform the kinematic analysis of the narrow H$\alpha$ component which indicates that the warm ionized gas velocity field is consistent with disk rotation. We also find that, in the innermost nuclear regions ($< 1.5$ kpc), the intrinsic velocity dispersion of the disk reaches $\sim 150$ km/s, $\sim 2-3$ times higher than the velocity dispersion inferred from the [CII] 158$\mu$m line tracing mostly cold gas. Since, at large radii, the velocity dispersion of the warm and cold gas are comparable, we conclude that the outflows are injecting turbulence in the warm ionized gas in the central region, but they are not sufficiently powerful to disrupt the dense gas and quench star formation. These findings support the scenario that dust-obscured galaxies represent the evolutionary stage preceding the unobscured quasar when all gas and dust are removed from the host.

Domaines: Astrophysique [astro-ph]

Eleonora Parlanti, Stefano Carniani, Hannah Übler, Giacomo Venturi, Francesco d'Eugenio, et al.. GA-NIFS: Early-stage feedback in a heavily obscured AGN at $z=4.76$. Astronomy and Astrophysics - A&A, 2024, ⟨10.1051/0004-6361/202347914⟩. ⟨hal-04230073⟩