Energetic galaxy-wide outflows in high-redshift ultra-luminous infrared
  galaxies hosting AGN activity
  We present integral field spectroscopy observations, covering the [O
III]4959,5007 emission-line doublet of eight high-redshift (z=1.4-3.4)
ultra-luminous infrared galaxies (ULIRGs) that host Active Galactic Nuclei
(AGN) activity, including known sub-millimetre luminous galaxies (SMGs). The
targets have moderate radio luminosities that are typical of high-redshift
ULIRGs (L(1.4GHz)=10^(24)-10^(25)W/Hz) and therefore are not radio-loud AGN. We
de-couple kinematic components due to the galaxy dynamics and mergers from
those due to outflows. We find evidence in the four most luminous systems (L([O
III])>~10^(43)erg/s) for the signatures of large-scale energetic outflows:
extremely broad [O III] emission (FWHM ~ 700-1400km/s) across ~4-15kpc, with
high velocity offsets from the systemic redshifts (up to ~850km/s). The four
less luminous systems have lower quality data displaying weaker evidence for
spatially extended outflows. We estimate that these outflows are potentially
depositing energy into their host galaxies at considerable rates
(~10^(43)-10^(45)erg/s); however, due to the lack of constraints on the density
of the outflowing material and the structure of the outflow, these estimates
should be taken as illustrative only. Based on the measured maximum velocities
(v(max)~400-1400km/s) the outflows observed are likely to unbind some fraction
of the gas from their host galaxies, but are unlikely to completely remove gas
from the galaxy haloes. By using a combination of energetic arguments and a
comparison to ULIRGs without clear evidence for AGN activity, we show that the
AGN activity could be the dominant power source for driving all of the observed
outflows, although star formation may also play a significant role in some of
the sources.
