Galaxy formation with radiative and chemical feedback

TL;DR

GAMESH is a new pipeline integrating radiative and chemical feedback into galaxy formation models, enabling realistic simulations that match observed properties of the Milky Way and its satellites.

Contribution

It introduces GAMESH, a novel combined radiative transfer and chemical evolution pipeline for galaxy formation simulations, bridging semi-analytic and numerical approaches.

Findings

Predicted star formation rates and metal enrichment match observations.

Reionisation history aligns with empirical data.

Metallicity distribution functions of halo stars are accurately reproduced.

Abstract

Here we introduce GAMESH, a novel pipeline which implements self-consistent radiative and chemical feedback in a computational model of galaxy formation. By combining the cosmological chemical-evolution model GAMETE with the radiative transfer code CRASH, GAMESH can post process realistic outputs of a N-body simulation describing the redshift evolution of the forming galaxy. After introducing the GAMESH implementation and its features, we apply the code to a low-resolution N-body simulation of the Milky Way formation and we investigate the combined effects of self-consistent radiative and chemical feedback. Many physical properties, which can be directly compared with observations in the Galaxy and its surrounding satellites, are predicted by the code along the merger-tree assembly. The resulting redshift evolution of the Local Group star formation rates, reionisation and metal enrichment along with the predicted Metallicity Distribution Function of halo stars are critically compared with observations. We discuss the merits and limitations of the first release of GAMESH, also opening new directions to a full implementation of feedback processes in galaxy formation models by combining semi-analytic and numerical methods.