Characterization of morphological properties of galaxy groups and clusters in the eROSITA Final Equatorial-Depth Survey (eFEDS)

The eROSITA Final Equatorial-Depth Survey (eFEDS) is a 140 square degree area observed during the performance verification phase of eROSITA. It was observed at a similar exposure to the expected exposure in the final all-sky survey in equatorial regions. In this area, we detect 542 clusters. We have studied the morphological properties of the eFEDS clusters by modelling how these properties depend on redshift and luminosity. Using a novel technique, we combine 12 morphology estimators in a single measurement that indicate the relaxation state of the detected clusters. We further investigate the underlying cluster populations (with relaxed and unrelaxed morphology) in the eFEDS cluster sample and find that a simple unimodal distribution is always preferred in this sample. Finally, we investigate the redshift evolution of the relaxed cluster fraction and find no evidence for significant redshift evolution. I will present the results of this work, which is published in arXiv:2106.15086