The Extreme Local Environments of High-z Quasars

The environments of high-redshift quasars are a key probe of the formation and growth of supermassive black holes in the early Universe. I will present our work using the JWST NIRSpec IFU to study the local kpc-scale environments of high-z quasars in great detail. In the GA-NIFS program, we have discovered a large number of interacting companion galaxies around our sample of quasars, undergoing major mergers with the quasar hosts. For one of these quasars we have measured a black hole to stellar mass ratio of ~60%, the most overmassive black hole measured to date. As part of the PEARLS program we have also discovered a quasar undergoing a train wreck merger with multiple galaxies and a tidal bridge, with potentially one of the most extreme outflows in the universe. I will show these latest results, and discuss how we can use these new observations to help understand the growth of the first black holes.