Powerful quasar outflow in a massive disc galaxy at $z \sim 5$
  There is growing observational evidence of high-redshift quasars launching
energetic, fast outflows, but the effects that these have on their host
galaxies is poorly understood. We employ the moving-mesh code AREPO to study
the feedback from a quasar that has grown to $\sim 10^9 M_\odot$ by $z \sim 5$
and the impact that this has on its host galaxy. Our simulations use a
super-Lagrangian refinement technique to increase the accuracy with which the
interface of the quasar-driven wind and the surrounding gas is resolved. We
find that the feedback injected in these simulations is less efficient at
removing gas from the galaxy than in an identical simulation with no
super-Lagrangian refinement. This leads to the growth of a massive,
rotationally supported, star-forming disc, co-existing with a powerful
quasar-driven outflow. The properties of our host galaxy, including the
kinematical structure of the gaseous disc and of the outflow, are in good
agreement with current observations. Upcoming ALMA and JWST observations will
be an excellent test of our model and will provide further clues as to the
variance in properties of high-redshift quasar hosts.
