Imprints of the cosmic void evolution on the baryon processes inside galaxy haloes

TL;DR

This study uses hydrodynamic simulations to explore how the large-scale environment of cosmic voids influences galaxy formation and baryonic processes within haloes, revealing differences based on void dynamics.

Contribution

It provides new insights into how void environments and their dynamical states affect baryonic evolution and halo assembly, a topic less explored in previous research.

Findings

Halos in voids have less baryonic and stellar content than those in the general universe.

Halo assembly rates vary with the void's dynamical state, affecting baryonic processes.

Void environment modulates galaxy formation mechanisms depending on expansion or contraction.

Abstract

Cosmic voids provide a unique environment to study galaxy formation and evolution. In this paper, we analyse a set of hydrodynamic zoom-in simulations of voids, to analyse in detail their inner structures. These voids were identified in a cosmological simulation and classified according to their surrounding dynamics at very large scales: whether they are in expansion or contraction at their outskirts. We study how these environments and the dynamics of voids impact the baryonic processes inside haloes and their mechanisms of formation and evolution. We find an under-abundance of processed gas within the voids that can be associated with the lack of massive haloes. By studying the dynamical phase-space diagram of haloes and the halo-particle correlation function, we find that haloes inside of contracting voids are slightly affected by the presence of bigger structures, in comparison to haloes in the inner regions of expanding voids. Consistent signals are obtained both when using dark matter and gas particles. We show that the halo assembly depends on the void dynamical state: haloes in expanding voids assemble slowly than those in contracting voids and in the general universe. This difference in the assembly impacts the baryonic evolution of haloes. Overall the redshift range analysed, haloes in voids have less baryon content than haloes in the general universe and particularly at z = 0 less stellar content. Our results suggest that the large scale void environment modulate the baryonic process occurring inside haloes according to the void dynamical state.