Powerful quasar outflow in a massive disc galaxy at $z \sim 5$

TL;DR

This study uses advanced simulations to explore how energetic quasar outflows at high redshift influence their host galaxies, revealing the formation of massive star-forming discs alongside powerful outflows, consistent with current observations.

Contribution

The paper introduces a novel simulation approach with super-Lagrangian refinement to better resolve quasar-driven winds and their effects on galaxy evolution at high redshift.

Findings

Quasar feedback is less efficient at gas removal with super-Lagrangian refinement.

A massive, star-forming disc coexists with a powerful outflow.

Simulation results align with current high-redshift galaxy observations.

Abstract

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.