Multi-phase outflows in high redshift quasar host galaxies
  We present Atacama Large Millimeter/submillimeter Array (ALMA) observations
of six radio-loud quasar host galaxies at $z=1.4-2.3$. We combine the kpc-scale
resolution ALMA observations with high spatial-resolution adaptive optics
integral field spectrograph data of the ionized gas. We detect molecular gas
emission in five quasar host galaxies and resolve the molecular interstellar
medium using the CO (3-2) or CO (4-3) rotational transitions. Clumpy molecular
outflows are detected in four quasar host galaxies and in a merger system 21
kpc away from one quasar. Between the ionized and cold-molecular gas phases,
the majority of the outflowing mass is in a molecular phase, while for three
out of four detected multi-phase gas outflows, the majority of the kinetic
luminosity and momentum flux is in the ionized phase. Combining the energetics
of the multi-phase outflows, we find that their driving mechanism is consistent
with energy-conserving shocks produced by the impact of the quasar jets with
the gas in the galaxy. By assessing the molecular gas mass to the dynamics of
the outflows, we estimate a molecular gas depletion time scale of a few Myr.
The gas outflow rates exceed the star formation rates, suggesting that quasar
feedback is a major mechanism of gas depletion at the present time. The
coupling efficiency between the kinetic luminosity of the outflows and the
bolometric luminosity of the quasar of 0.1-1% is consistent with theoretical
predictions. Studying multi-phase gas outflows at high redshift is important
for quantifying the impact of negative feedback in shaping the evolution of
massive galaxies.
