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

¹ IRAP, Université de Toulouse, CNRS, CNES, UPS, Toulouse, France
e-mail: edoardo.cucchetti@irap.omp.eu
² CNES, 18 Avenue Edouard Belin, 31400 Toulouse, France
³ INAF, Osservatorio Astronomico di Trieste, Via Tiepolo 11, 34131 Trieste, Italy
⁴ Dipartimento di Fisica dell’Università di Trieste, Sezione di Astronomia, Via Tiepolo 11, 34131 Trieste, Italy
⁵ INFN – National Institute for Nuclear Physics, Via Valerio 2, 34127 Trieste, Italy
⁶ University Observatory Munich, Scheinerstr. 1, 81679 Munich, Germany
⁷ Max Plank Institut für Astrophysik, Karl-Schwarzschield Strasse 1, 85748 Garching bei Munchen, Germany
⁸ Dipartimento di Fisica e Astronomia, Università di Bologna, Via Gobetti 93, 40127 Bologna, Italy
⁹ INAF, Osservatorio di Astrofisica e Scienza dello Spazio, Via Pietro Gobetti 93/3, 40129 Bologna, Italy
¹⁰ INFN, Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy
¹¹ Department of Astrophysical Sciences, Princeton University, Princeton, NJ, 08544, USA
¹² Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA, 02138, USA
¹³ Dr. Karl Remeis-Observatory and Erlangen Centre for Astroparticle Physics, Sternwartstr. 7, 96049 Bamberg, Germany

Received: 23 July 2018
Accepted: 24 September 2018

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 have also quantified 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 of unveiling the properties of the ICM but also stresses the data analysis challenges faced by future high-resolution X-ray missions such as Athena.