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

July 2025 • 2025ApJ...987L..15C

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

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 (northwest─southeast) and consists of at least three subclumps aligned with the brightest cluster galaxies. The subcluster is more compact but elongated along the east─west direction, with a single dominant peak. We also detect a possible mass and intracluster light (ICL) trail extending from the subcluster's eastern side toward the main cluster. Notably, these detailed features are closely traced by the ICL, with a modified Hausdorff distance of 19.80 ± 12.46 kpc. Together with multiwavelength data, the complex mass distribution suggests that the merger history of the Bullet Cluster may be more complex than previous binary cluster merger scenarios.

Links

• SIMBAD https://simbad.u-strasbg.fr/simbad/sim-ref?querymethod=bib&simbo=on&submit=submit+bibcode&bibcode=2025ApJ...987L..15C
• PDF https://iopscience.iop.org/article/10.3847/2041-8213/add2f0/pdf
• PREPRINT http://arxiv.org/abs/2503.21870
• DATA https://archive.stsci.edu/mastbibref.php?bibcode=2025ApJ...987L..15C
• DATA https://archive.stsci.edu/mastbibref.php?bibcode=2025ApJ...987L..15C
• DATA https://cda.harvard.edu/chaser?obsid=3184,4984,4985,4986,5355,5356,5357,5358,5361
• ELECTR https://doi.org/10.3847/2041-8213/add2f0