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arXiv · 2503.21870

A High-Caliber View of the Bullet Cluster Through JWST Strong and Weak Lensing Analyses

Sangjun Cha·Boseong Young Cho·Hyungjin Joo·Wonki Lee·Kim HyeongHan·Zachary P. Scofield·Kyle Finner·M. James Jee
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Abstract

The Bullet Cluster (1E 0657-56) is a key astrophysical laboratory for studying dark matter, galaxy cluster mergers, and shock propagation in extreme environments. Using new JWST imaging, we present the highest-resolution mass reconstruction to date, combining 146 strong lensing constraints from 37 systems with high-density (398 sources arcmin$^{-2}$) weak lensing data, without assuming that light traces mass. The main cluster's mass distribution is highly elongated (NW-SE) and consists of at least three subclumps aligned with the brightest cluster galaxies. The subcluster is more compact but elongated along the E-W direction, with a single dominant peak. We also detect a possible mass and ICL trail extending from the subcluster's eastern side toward the main cluster. Notably, these detailed features are closely traced by the intracluster light, with a modified Hausdorff distance of $19.80 \pm 12.46$ kpc. Together with multi-wavelength data, the complex mass distribution suggests that the merger history of the Bullet Cluster may be more complex than previous binary cluster merger scenarios.

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Sangjun Cha, Boseong Young Cho, Hyungjin Joo, Wonki Lee, Kim HyeongHan, Zachary P. Scofield, Kyle Finner, M. James Jee. 2025-03-27. A High-Caliber View of the Bullet Cluster Through JWST Strong and Weak Lensing Analyses. https://doi.org/10.3847/2041-8213%2Fadd2f0

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