English

A major galaxy cluster merger caught by eROSITA: weak lensing mass distribution and kinematic description

Cosmology and Nongalactic Astrophysics 2022-08-17 v1

Abstract

We present the weak lensing mass distribution of a triple merging cluster candidate at zphoto0.36z_{\rm photo}\sim 0.36 belonging to a supercluster recently discovered during the eROSITA Performance Verification phase. Our analysis solved a previous tension in the merger classification by confirming that the cluster pair eFEDS J093513.3+004746 and eFEDS J093510.7+004910 is undergoing a major merger with a mass ratio 1.70.7+0.51.7_{-0.7}^{+0.5}. According to our two-body kinematic description, the encounter happened 0.580.20+0.150.58_{-0.20}^{+0.15} Gyr ago, in a scenario that supports the observed radio relic position at the cluster outskirts. However, the same analysis showed that the companion cluster, eFEDS J093501.1+005418, is not gravitationally bound to the interacting system and therefore it is not part of the supercluster. We also checked the impact of adopting a scaling relation to determine the halo concentration c200c_{200}. At the observed merger stage, where the clusters have travelled \sim55 per cent of the path to reach the apoapsis, the choice of the c200c_{200} (whether from a scaling relation or a free parameter in the mass model) does not change significantly either the cluster masses or the kinematic description.

Keywords

Cite

@article{arxiv.2207.02232,
  title  = {A major galaxy cluster merger caught by eROSITA: weak lensing mass distribution and kinematic description},
  author = {Rogério Monteiro-Oliveira},
  journal= {arXiv preprint arXiv:2207.02232},
  year   = {2022}
}

Comments

12 pages, 9 figures, 4 tables. Submitted to MNRAS (2nd revision)