Program: GN-2008A-Q-63

We propose observations to trace the process of feedback in radio galaxies at z~1, the likely antecendents of massive, present-day giant ellipticals, to determine the dominant process by which this crucial aspect of galaxy formation takes place. The only way to test whether the feedback is of starburst- or AGN-origin is with spatially resolved kinematic information which can only be gleaned from integral-field spectroscopy. Our proposed observations will probe the relationship between dark halo mass, gas mass and the inferred star-formation rate and their possible effect/dependence on the chemical abundance and the global dynamics of the hosts and large-scale extended emission-line haloes around z~1 radio galaxies as a function of radio luminosity. Thus, we will be in the unique position of being able to trace the evolution of the most massive active galaxies at z~1.