The eROSITA Final Equatorial-Depth Survey (eFEDS) X-ray properties and scaling relations of galaxy clusters and groups

Bahar, Y. Emre; Bulbul, Esra; Clerc, Nicolas; Ghirardini, Vittorio; Liu, Ang; Nandra, Kirpal; Pacaud, Florian; Chiu, I-Non; Comparat, Johan; Ider-Chitham, Jacob; Klein, Mathias; Liu, Teng; Merloni, Andrea; Migkas, Konstantinos; Okabe, Nobuhiro; Ramos-Ceja, Miriam E.; Reiprich, Thomas H.; Sanders, Jeremy S. und Schrabback, Tim (2022): The eROSITA Final Equatorial-Depth Survey (eFEDS) X-ray properties and scaling relations of galaxy clusters and groups. In: Astronomy & Astrophysics, Bd. 661, A7

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 (L-X, L-bol, T, M-gas, Y-X) within R-500 for 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 500 and core-excised 0.15 R-500-R-500 apertures 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 between L-X - T, L-X - M-gas, L-X - Y-X, L-bol - T, L-bol - M-gas, L-bol - Y-X, and M-gas - T. We find that the best-fit slopes significantly deviate from the self-similar model at a >4 sigma 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 to R-500 with survey-depth exposures and constrain the scaling relations in a wide mass-luminosity-redshift range.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0004-6361
• Sprache: Englisch