Stirring the cosmic pot: how black hole feedback shapes the matter power spectrum in the Fable simulations

TL;DR

This study investigates how different models of black hole feedback in the Fable simulations influence the matter power spectrum, revealing significant suppression effects at certain scales and redshifts, crucial for interpreting upcoming galaxy survey data.

Contribution

It provides a detailed analysis of the impact of various AGN feedback models on the cosmic matter power spectrum across different epochs in the Fable simulation suite.

Findings

AGN feedback suppresses clustering at $k \,\sim\, 10\,h\,cMpc^{-1}$ at $z=0$

Radio mode feedback affects larger scales and later times more strongly

Suppression of matter power spectrum is driven by AGN effects inside haloes at $z=0$ and both inside and outside at higher redshifts

Abstract

Understanding the impact of baryonic physics on cosmic structure formation is crucial for accurate cosmological predictions, especially as we usher in the era of large galaxy surveys with the Rubin Observatory as well as the Euclid and Roman Space Telescopes. A key process that can redistribute matter across a large range of scales is feedback from accreting supermassive black holes. How exactly these active galactic nuclei (AGN) operate from sub-parsec to Mega-parsec scales however remains largely unknown. To understand this, we investigate how different AGN feedback models in the Fable simulation suite affect the cosmic evolution of the matter power spectrum (MPS). Our analysis reveals that AGN feedback significantly suppresses clustering at scales $k \sim 10\,h\,cMpc^{-1}$, with the strongest effect at redshift $z = 0$ causing a reduction of $\sim 10\%$ with respect to the dark matter-only simulation. This is due to the efficient feedback in both radio (low Eddington ratio) and quasar (high Eddington ratio) modes in our fiducial Fable model. We find that variations of the quasar and radio mode feedback with respect to the fiducial Fable model have distinct effects on the MPS redshift evolution, with the radio mode being more effective on larger scales and later epochs. Furthermore, MPS suppression is dominated by AGN feedback effects inside haloes at $z = 0$, while for $z \gtrsim 1$ the matter distribution both inside and outside of haloes shapes the MPS suppression. Hence, future observations probing earlier cosmic times beyond $z \sim 1$ will be instrumental in constraining the nature of AGN feedback.