The eROSITA Final Equatorial-Depth Survey (eFEDS)

Abstract

Context.Scaling relations link the physical properties of clusters at cosmic scales. They are used to probe the evolution of large-scale structure, estimate observables of clusters, and constrain cosmological parameters through cluster counts.Aims.We investigate the scaling relations between X-ray observables of the clusters detected in the eFEDS field using Spectrum-Roentgen-Gamma/eROSITA observations taking into account the selection effects and the distributions of observables with cosmic time.Methods.We extract X-ray observables (LX,Lbol,T,Mgas,YX) withinR500for the sample of 542 clusters in the eFEDS field. By applying detection and extent likelihood cuts, we construct a subsample of 265 clusters with a contamination level of <10% (including AGNs and spurious fluctuations) to be used in our scaling relations analysis. The selection function based on the state-of-the-art simulations of the eROSITA sky is fully accounted for in our work.Results.We provide the X-ray observables in the core-included <R500and core-excised 0.15R500-R500apertures for 542 galaxy clusters and groups detected in the eFEDS field. Additionally, we present our best-fit results for the normalization, slope, redshift evolution, and intrinsic scatter parameters of the X-ray scaling relations betweenLX-T,LX-Mgas,LX-YX,Lbol-T,Lbol-Mgas,Lbol-YX, andMgas-T. We find that the best-fit slopes significantly deviate from the self-similar model at a >4σ confidence level, but our results are nevertheless in good agreement with the simulations including non-gravitational physics, and the recent results that take into account selection effects.Conclusions.The strong deviations we find from the self-similar scenario indicate that the non-gravitational effects play an important role in shaping the observed physical state of clusters. This work extends the scaling relations to the low-mass, low-luminosity galaxy cluster and group regime using eFEDS observations, demonstrating the ability of eROSITA to measure emission from the intracluster medium out toR500with survey-depth exposures and constrain the scaling relations in a wide mass-luminosity-redshift range.