Caption: Simulated wavelet filtered image of an 80 ks Athena/WFI observation. Cosmic X-ray background, galactic foreground, and particle background are included as well as telescope vignetting and PSF degradation with an off-axis angle. The green circles correspond to the input groups at z=2.5 with M₅₀₀= 5×10¹³ M_Sun and the white squares to sources detected as extended galaxy groups through the wavelet filtering process and the maximum likelihood fitting algorithm: it can be clearly seen that moderate exposures with Athena/WFI processed with state-of-the-art software can detect very distant groups to uncover the mysteries of their origin and evolution.

Creation date: September 2018.

Credits: Chaoli Zhang, Miriam Ramos-Ceja, Florian Pacaud, Thomas H. Reiprich, and also the SIXTE team.