Weak-Lensing Analysis of the Complex Cluster Merger Abell 746 with Subaru/Hyper Suprime-Cam

TL;DR

This study uses Subaru/Hyper Suprime-Cam data to analyze the complex merging galaxy cluster Abell 746 through weak-lensing, revealing its mass distribution and confirming previous mass estimates despite the merger's complexity.

Contribution

First weak-lensing analysis of Abell 746 that maps its mass distribution and compares it with multi-wavelength data, highlighting the challenges in interpreting complex merging systems.

Findings

Mass estimate $M_{500}=4.4 extpm1.0 imes 10^{14} M_\odot$ consistent with previous SZ and X-ray results.

Mass distribution shows a main peak with extensions toward the north and west.

Reconciliation of mass, galaxy, and intracluster medium distributions with radio features remains challenging.

Abstract

The galaxy cluster Abell 746 (A746; $z$=0.214), featuring a double radio relic system, two isolated radio relics, a possible radio halo, disturbed V-shaped X-ray emission, and intricate galaxy distributions, is a unique and complex merging system. We present a weak-lensing analysis of A746 based on wide-field imaging data from Subaru/Hyper Suprime-Cam observations. The mass distribution is characterized by a main peak which coincides with the center of the X-ray emission. At this main peak, we detect two extensions toward the north and west, tracing the cluster galaxy and X-ray distributions. Despite the ongoing merger, our estimate of the A746 global mass $M_{500}=4.4\pm1.0\times10^{14}~M_{\odot}$ is consistent with the previous results from SZ and X-ray observations. We conclude that reconciling the distributions of mass, galaxies, and intracluster medium with the double radio relic system and other radio features remains challenging.