Multi-phase AGN feedback and an extended [CII] halo in a LoBAL quasar at z ∼ 6.6

Hyunseop Choi ( Université de Montréal )

In this talk, I will present the results from the first multi-scale and multi-phase characterization of black-hole driven outflows in the z ∼ 6.6 quasar J0923+0402 and discuss how these winds impact the cold gas reservoir. We employed the SimBAL spectral synthesis to fit broad absorption line features in the rest-UV spectrum and found a powerful ionized outflow on < 210 pc scale, with a kinetic power ∼ 2 − 100% of the quasar luminosity. ALMA observations revealed high-velocity [CII] emission, likely associated with a cold neutral outflow at ∼ 0.5−2 kpc scale in the host-galaxy, and a bright extended [CII] halo with a size of ∼ 15 kpc. For the first time at such an early epoch, we accurately constrained the outflow energetics in both the ionized and the atomic neutral gas phases. The results of this work indicate that strong black hole feedback is occurring in quasars at z > 6 and is likely responsible for shaping the properties of the cold gas reservoir up to circum-galactic scales. Finally, I will share future plans with our approved JWST GO3 program.