Relatore
Descrizione
In this talk, I will focus on CANUCS-LRD-z8.6, one of the highest-redshift spectroscopically confirmed LRD at z = 8.6319, which hosts an accreting SMBH and shows broad Hβ, high-ionization UV lines (e.g., CIV, NIV), very low metallicity (Z < 0.1 Zsun), and a BH mass exceeding that expected from its host. These properties suggest accelerated SMBH growth relative to the galaxy (Tripodi+25, Nat. Comm., 16, 9830).
I will also introduce JWST/NIRCam+NIRSpec results on Bz5.3, a broad-line AGN at z = 5.3 behind the Bullet Cluster (Tripodi+25, ApJL,994, L6). Strong Fe II, O I, and Ca II triplet lines, along with broad Balmer emission, confirm the presence of a stratified broad-line region (BLR). Remarkably, we report the first high-redshift detection of the λ1304 bump (O I + Si II), commonly observed in local AGNs. I will also discuss the implications on the excitation mechanisms of the BLR based on low-ionization line diagnostics. Photoionization modeling also reveals multiple gas phases in the BLR with diverse densities and ionization states. Finally, I will discuss the potential role of environment in shaping the evolution of LRDs based on the latest available JWST observations, and I will present an empirical classification of the spectroscopic diversity of LRDs (Perez-Gonzalez, RT incl, 2026; arXiv:2602.20247).
| Sessione | Evoluzione delle galassie |
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