2025ApJ...984...26A -
Astrophys. J., 984, 26 (2025/May-1)
PSZ2 G181.06+48.47. III. Weak-lensing Analysis and Merging Scenario Reconstruction of a Low-mass Cluster with Exceptionally Distant Radio Relics.
AHN E., CHO H., JEE M.J., LEE W., STROE A., RAJPUROHIT K., FINNER K., FORMAN W., JONES C. and VAN WEEREN R.
Abstract (from CDS):
The galaxy cluster PSZ2 G181.06+48.47 (z = 0.234) is a post-merging system that exhibits symmetric double radio relics separated by ∼2.7 Mpc. We present the first weak-lensing analysis of PSZ2 G181.06+48.47 and propose possible merging scenarios using numerical simulations. Our analysis with Subaru Hyper Suprime-Cam imaging identifies a binary dark matter (DM) structure consisting of northern and southern components, separated by ∼500 kpc. Assuming Navarro-Frenk-White (NFW) halos, the masses for the northern and southern subclusters are ${M}_{200c}^{\,\rm{N}\,}=0.8{8}_{-0.30}^{+0.35}\times 1{0}^{14}{M}_{\odot }$ and ${M}_{200c}^{\,\rm{S}\,}=2.7{1}_{-0.48}^{+0.51}\times 1{0}^{14}{M}_{\odot }$, respectively. By superposing the two NFW halos, we determine the total mass of the cluster to be ${M}_{200c}=4.2{2}_{-1.00}^{+1.10}\times 1{0}^{14}{M}_{\odot }$(${M}_{500c}=2.9{0}_{-0.69}^{+0.75}\times 1{0}^{14}{M}_{\odot }$). Our mass estimate suggests that the two relics are located around the cluster R200c, where the density of the intracluster medium is very low. Our idealized simulations find that an off-axis collision of a 3:1 major merger can simultaneously reproduce the observed relic and DM halo separations. From these findings, we suggest that the system is observed ∼0.9 Gyr after the first pericenter passage and is returning from the first apocenter.
Abstract Copyright:
© 2025. The Author(s). Published by the American Astronomical Society.
Journal keyword(s):
Galaxy clusters - Weak gravitational lensing - Radio continuum emission
Simbad objects:
7
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