Mocking a z=2 galaxy group with ATHENA/X-IFU

We investigate the capabilities of an X-ray integral field Unit such as X-IFU on board ATHENA to unveil the gas physics of distant groups of galaxies in the Universe. We make use of a simulated galaxy group at redshift z = 2 with mass M₅₀₀=7 10¹³ M_sun, extracted from the HYDRANGEA cosmological SPH simulation. We perform a mock observation with the X-IFU instrument, using the SIXTE software suite. We post-process the mock data in a forward-modelling analysis enabled by Monte-Carlo sampling of the parameter space, in order to recover the main thermodynamical and chemical distribution such as the density, temperature, entropy, pressure as well as abundances distribution for key chemical elements such as Fe, Si, Mg. In complement to our high spectral resolution study, we run a mock observation of our simulated distant group with an X-ray wide field imager such as the WFI/ATHENA to take advantage of the smaller pixel size, and in order to investigate the synergy between the two complementary instruments. We present here quantitative results of this feasibility study in view of the ATHENA scientific requirements.