The SINFONI survey of powerful radio galaxies at z~2: Jet-driven AGN
  feedback during the Quasar Era
  We present VLT/SINFONI imaging spectroscopy of the warm ionized gas in 33
powerful radio galaxies at redshifts z>~2, which are excellent sites to study
the interplay of rapidly accreting active galactic nuclei and the interstellar
medium of the host galaxy in the very late formation stages of massive
galaxies. Our targets span two orders of magnitude in radio size (2-400 kpc)
and kinetic jet energy (a few 10^46 to almost 10^48 erg s^-1). All sources have
complex gas kinematics with broad line widths up to ~1300 km s^-1. About half
have bipolar velocity fields with offsets up to 1500 km s^-1 and are consistent
with global back-to-back outflows. The others have complex velocity
distributions, often with multiple abrupt velocity jumps far from the nucleus
of the galaxy, and are not associated with a major merger in any obvious way.
We present several empirical constraints that show why gas kinematics and radio
jets seem to be physically related. The gas kinetic energy from large scale
bulk and local outflow or turbulent motion corresponds to a few 10^-3 to 10^-2
of the kinetic energy of the jet. In galaxies with jet power >~10^47 erg s^-1,
the bulk kinetic energy dominates the total energy budget of the gas,
suggesting that the outflows encompasses the global interstellar medium,
perhaps facilitated by the strong gas turbulence. We compare with recent
hydrodynamic simulations, and discuss the potential consequences for the
subsequent evolution of massive high-z galaxies. The gas-phase metallicities in
our galaxies are lower than in most low-z AGN, but nonetheless solar or even
super-solar, suggesting that the ISM in these galaxies is very similar to the
gas from which massive low-redshift galaxies formed most of their gas. This
further highlights that we are seeing these galaxies near the end of their
active formation phase.
