Weak Lensing Results of the Merging Cluster A1758

TL;DR

This paper presents weak lensing analysis of the merging galaxy cluster A1758, revealing complex mass distribution and separation of gas and dark matter, with implications for understanding cluster mergers.

Contribution

The study provides detailed weak lensing results of A1758, including mass estimates and the identification of strong lensing candidates, highlighting unique merger geometry.

Findings

Mass of A1758N estimated at 2.2±0.5×10^15 M_sun

Weak lensing mass peaks separated at 2.5 sigma

Detection of seven strong lensing candidates

Abstract

Here we present the weak lensing results of A1758, which is known to consist of four subclusters undergoing two separate mergers, A1758N and A1758S. Weak lensing results of A1758N agree with previous weak lensing results of clusters 1E0657-558 (Bullet cluster) and MACS J0025.4-1222, whose X-ray gas components were found to be largely separated from their clusters' gravitational potentials. A1758N has a geometry that is different from previously published mergers in that one of its X-ray peaks overlays the corresponding gravitational potential and the other X-ray peak is well separated from its cluster's gravitational potential. The weak lensing mass peaks of the two northern clusters are separated at the 2.5 sigma level. We estimate the combined mass of the clusters in A1758N to be 2.2+/-0.5*10^15 M_sun and r_200=2300(+100/-130) kpc. We also detect seven strong lensing candidates, two of which may provide information that would improve the mass measurements of A1758N.