The Role of Quasar Radiative Feedback on Galaxy Formation during Cosmic Reionization

TL;DR

This study uses 3D radiative transfer simulations to show that quasar radiation suppresses star formation in low-mass galaxies during cosmic reionization, affecting galaxy luminosity functions and aiding in environmental analysis.

Contribution

The paper introduces detailed 3D radiative transfer simulations to quantify quasar radiative feedback effects on galaxy formation during reionization.

Findings

Quasar radiation suppresses star formation in low-mass galaxies.

Photo-dissociation of molecular hydrogen is the main suppression mechanism.

Bright galaxy counts can reveal quasar environment overdensities.

Abstract

Recent observations have found that many $z\sim 6$ quasar fields lack galaxies. This unexpected lack of galaxies may potentially be explained by quasar radiation feedback. In this paper I present a suite of 3D radiative transfer cosmological simulations of quasar fields. I find that quasar radiation suppresses star formation in low mass galaxies, mainly by photo-dissociating their molecular hydrogen. Photo-heating also plays a role, but only after $\sim$100 Myr. However, galaxies which already have stellar mass above $10^5 M_\odot$ when the quasar turns on will not be suppressed significantly. Quasar radiative feedback suppresses the faint end of the galaxy luminosity function (LF) within $1$ pMpc, but to a far lesser degree than the field-to-field variation of the LF. My study also suggests that by using the number of bright galaxies ($M_{1500}<-16$) around quasars, we can potentially recover the underlying mass overdensity, which allows us to put reliable constraints on quasar environments.