• Corpus ID: 249890302

The eROSITA Final Equatorial Survey (eFEDS): X-ray properties of Subaru optically-selected clusters

@inproceedings{Ota2022TheEF,
  title={The eROSITA Final Equatorial Survey (eFEDS): X-ray properties of Subaru optically-selected clusters},
  author={Naomi Ota and N. T. Nguyen-Dang and Ikuyuki Mitsuishi and Masamune Oguri and M. Klein and Nobuhiro Okabe and Miriam E Ramos-Ceja and Thomas. H. Reiprich and F. Pacaud and Esra Bulbul and Marcus Bruggen and A. Liu and Konstantinos Migkas and I Chiu and Vittorio Ghirardini and Sebastian Grandis and Y-T. Lin and Hironao Miyatake and Satoshi Miyazaki and Jeremy S Sanders},
  year={2022}
}

• N. Ota, N. T. Nguyen-Dang, +17 authors J. Sanders
• Published 20 June 2022
• Physics

Context. We present the results from a systematic X-ray analysis of Subaru optically-selected clusters with high cluster richness in the eROSITA Final Equatorial-Depth Survey (eFEDS) field. Aims. By a joint analysis of SRG(Spectrum Roentgen Gamma)/eROSITA and Subaru/HSC surveys, we aim to investigate the dynamical status of the optically-selected clusters and derive the cluster scaling relations. Methods. The sample consists of 43 optically-selected galaxy clusters with richness > 40 in the redshift range of 0.16–0.89. We systematically analyzed X-ray images and emission spectra using the eROSITA data. We identified the brightest cluster galaxy (BCG) using the optical and far-infrared databases and measured the offset between X-ray peak and BCG position as an indicator of the dynamical status. We investigated the luminosity-temperature and mass-luminosity relations based on eROSITA X-ray spectra and HSC weak-lensing data analyses. Results. The fraction of relaxed clusters is estimated to be 2(< 39)%, which is smaller than that of the X-ray-selected cluster samples. After correcting for a selection bias due to the richness cut, we obtained a shallow L − T slope of 2.0 ± 0.4, which is consistent with the predictions of the self-similar model and the new baseline model by Fujita & Aung (2019). The L−M slope of 1.5±0.3 agrees with the above theoretical models and that of the shear-selected clusters in the eFEDs field. Conclusions. Our analysis of the high-richness optical clusters yielded a small fraction of relaxed clusters and a shallow slope of the luminositytemperature relation. This suggests that the average X-ray properties of the optical clusters are likely to be different from those observed in the X-ray samples. Thus, the joint eROSITA and HSC observations are powerful in extending the analysis to a larger sample and understanding the selection effect towards establishing the cluster scaling relations.