The imprint of AGN-driven outflows on the CGM: the case of Ly-a nebulae around high-z quasars

AGN feedback is a multiscale process involving phenomena from sub-parsec accretion disk winds to galaxy-wide outflows which might have an effect on the Interstellar Medium (ISM), Circumgalactic Medium (CGM) and Intergalactic Medium (IGM). While AGN-driven outflows are routinely observed on ISM scales, their impact on the CGM remains unconstrained. In recent years, integral-field spectrographs such as VLT/MUSE and Keck/KCWI have revealed that luminous Lyα nebulae, extending from tens to hundreds of kiloparsecs, are ubiquitous around high-redshift quasars, providing a unique laboratory to study the impact of AGN feedback at CGM scales. Using a radiation-hydrodynamic cosmological simulation, Costa et. al (2022) predict that AGN-driven outflows can regulate the properties of the Lyα nebulae by clearing low-optical-depth paths in the host galaxy, thereby facilitating the escape and scattering of Lyα photons from the galactic nucleus into the CGM. In this talk, I present an observational test of this prediction using a sample of six quasars at z ≈ 2–3 surrounded by extended Lyα nebulae detected with VLT/MUSE and Keck/KCWI. We combine these data with new VLT/ERIS and Gemini/GNIRS observations targeting the [O III] λ5007 emission line to characterize the kinematics and energetics of ionized AGN-driven outflows on ISM scales. We detect ionized outflows in all sources and find a positive monotonic correlation between outflow kinetic power and both the size and luminosity of the associated Lyα nebulae. Additionally, we observe a spatial alignment between extended [O III] emission and the inner, brightest regions of the Lyα nebulae, suggesting a physical connection between ISM-scale outflows and CGM-scale emission. Our results provide tentative observational evidence of the theoretical prediction by Costa et. al (2022) that AGN-driven outflows play a key role in shaping the CGM by mediating the nuclear activity and the host galaxy environment. Our findings place new empirical constraints on feedback models and highlight the importance of jointly probing ISM and CGM scales to understand the global impact of AGN feedback across cosmic time.