Kinematic signatures of AGN feedback in moderately powerful radio
  galaxies at z~2 observed with SINFONI
  Most successful galaxy formation scenarios now postulate that the intense
star formation in massive, high-redshift galaxies during their major growth
period was truncated when powerful AGNs launched galaxy-wide outflows of gas
that removed large parts of the interstellar medium. The most powerful radio
galaxies at z~2 show clear signatures of such winds, but are too rare to be
good representatives of a generic phase in the evolution of all massive
galaxies at high redshift. Here we present SINFONI imaging spectroscopy of 12
radio galaxies at z~2 that are intermediate between the most powerful radio and
vigorous starburst galaxies in radio power, and common enough to represent a
generic phase in the early evolution of massive galaxies.
  The kinematic properties are diverse, with regular velocity gradients with
amplitudes of Delta v=200-400 km s^-1 as in rotating disks as well as irregular
kinematics with multiple velocity jumps of a few 100 km s^-1. Line widths are
generally high, typically around FWHM=800 km s^-1, consistent with wind
velocities in hydrodynamic models. A broad H-alpha line in one target implies a
black hole mass of a few 10^9 M$_sun. The ratio of line widths, sigma, to bulk
velocity, v, is so large that even the gas in galaxies with regular velocity
fields is unlikely to be gravitationally bound. It is unclear, however, whether
the large line widths are due to turbulence or unresolved, local outflows as
are sometimes observed at low redshifts. Comparison of the kinetic energy with
the energy supply from the AGN through jet and radiation pressure suggests that
the radio source still plays a dominant role for feedback, consistent with
low-redshift radio-loud quasars.
