Athena X-IFU synthetic observations of galaxy clusters to probe the chemical enrichment of the Universe

TL;DR

This study uses synthetic observations from simulations to demonstrate that the Athena X-IFU will significantly advance understanding of galaxy cluster ICM properties and chemical enrichment across cosmic time with high spatial and spectral resolution.

Contribution

It provides a detailed assessment of Athena X-IFU's future capabilities in mapping ICM properties and chemical abundances in galaxy clusters up to redshift 2 using synthetic observations.

Findings

X-IFU can map ICM properties with <5% bias

It can track chemical elements across cosmic time accurately

The study highlights data analysis challenges for future missions

Abstract

Answers to the metal production of the Universe can be found in galaxy clusters, notably within their Intra-Cluster Medium (ICM). The X-ray Integral Field Unit (X-IFU) on board the next-generation European X-ray observatory Athena (2030s) will provide the necessary leap forward in spatially-resolved spectroscopy required to disentangle the intricate mechanisms responsible for this chemical enrichment. In this paper, we investigate the future capabilities of the X-IFU in probing the hot gas within galaxy clusters. From a test sample of four clusters extracted from cosmological hydrodynamical simulations, we present comprehensive synthetic observations of these clusters at different redshifts (up to z = 2) and within the scaled radius R500 performed using the instrument simulator SIXTE. Through 100 ks exposures, we demonstrate that the X-IFU will provide spatially-resolved mapping of the ICM physical properties with little to no biases (<5%) and well within statistical uncertainties. The detailed study of abundance profiles and abundance ratios within R500 also highlights the power of the X-IFU in providing constraints on the various enrichment models. From synthetic observations out to z = 2, we also quantify its ability to track the chemical elements across cosmic time with excellent accuracy, and thereby to investigate the evolution of metal production mechanisms as well as the link to the stellar initial mass-function. Our study demonstrates the unprecedented capabilities of the X-IFU in unveiling the properties of the ICM but also stresses the data analysis challenges faced by future high-resolution X-ray missions such as Athena.