Caught in the act: diffuse stellar and Ly$\alpha$ emission around a halo-less quasar in the assembling cluster CARLA J0800+4029 at z=2

Sofia G. Gallego, Simona Mei, Emanuele Daddi +3

Extended Ly$\alpha$ emission is commonly detected around luminous quasars at $z\sim 2$-3 and traces cold gas in the circumgalactic environment of the AGN. Together with the spatial distr…