activity
20232026
most citedWeak-Lensing Detection of Intracluster Filaments in the Coma Cluster

21 citations · 75 across the 18 of their papers we have counts for

collaborators

20 papers

astro-ph.CO2026

Testing Offsets Between Cluster-Scale Halos and BCGs in Strong Lensing Models Using the Jackknife Method

Sangjun Cha, Marceau Limousin, M. James Jee

Offsets between cluster-scale dark matter halos and brightest cluster galaxies (BCGs) inferred from strong lensing (SL) models have been used to investigate cluster dynamics and da…

astro-ph.GA2026★ 2 cited

Baryonic mass budgets in the central regions of the Bullet Cluster and their consistency with strong lensing in MOND

Dong Zhang, Hosein Haghi, Elena Asencio +8

Strong lensing observations of the Bullet Cluster have traditionally been regarded as strong evidence for dark matter and a major challenge to Milgromian dynamics (MOND). The offse…

astro-ph.CO2026

A new measurement with SNe Requiem and Encore using

L. Bazzanini, G. Di Rosa, A. Acebron +24

We present a strong-lensing (SL) analysis of the galaxy cluster MACS J0138.0-2155 (z=0.336), the first known lens cluster discovered to host two distinct multiply imaged Type Ia su…

astro-ph.GA2026

Dark and Luminous Matter in the Coma Cluster: Probing Galaxy Cluster Assembly Through Filaments with Weak Lensing and Multiwavelength Observations

K. HyeongHan, K. Finner, M. James Jee +11

The Coma cluster (Abell 1656; ) is a nearby rich galaxy cluster and a key laboratory for studying cluster assembly in the Cosmic Web. We characterize its projected dark ma…

astro-ph.SR2026

Candidate Microlensing Brown Dwarfs in Binary Lens Systems from the 2023--2025 Observing Seasons

Cheongho Han, Andrzej Udalski, Ian A. Bond +62

We present detailed light-curve analyses of ten binary-lens microlensing events observed during the 2023--2025 seasons and selected as candidates for hosting brown-dwarf companions…

astro-ph.GA2026

Weak-lensing Analysis of Intracluster Filaments in Abell 2744: Matched-filter Scans and Stepwise 2D Tracing

Sangjun Cha, Kyle Finner, M. James Jee +1

We present a weak-lensing (WL) analysis of filamentary structures in the merging galaxy cluster Abell 2744 using wide-field Magellan/MegaCam imaging data. We employ two complementa…

astro-ph.GA2026

Mature but Still Growing: JWST Detection of the Earliest Intracluster Light at z ~ 2

Hyungjin Joo, M. James Jee, Kyle Finner +6

We present a JWST analysis of intracluster light (ICL) in XLSSC 122 at z = 1.98, currently the most distant known strong lensing galaxy cluster with an evolved member population. U…

astro-ph.GA2025

An Active Galaxy Cluster Merger at Cosmic Noon Revealed by JWST Weak Lensing and Multiwavelength Probes

Zachary P. Scofield, Kyle Finner, Hyungjin Joo +8

The galaxy cluster XLSSC~122 is a rare system at , hosting surprisingly evolved member galaxies when the Universe was only one-third of its present age. Leveraging deep J…

astro-ph.GA2025

Joint JWST-DECam Lensing Reveals That the Bullet Cluster Is a Minor Merger

Boseong Young Cho, M. James Jee, Hyungjin Joo +2

We present the first robust virial masses of the Bullet Cluster's three individual components from a joint weak+strong lensing analysis combining JWST/NIRCam and DECam observations…

astro-ph.CO2025★ 1 cited

Reproducing Abell 2744 with the HyperMillennium Simulation

Qiao Wang, Ming Li, Liang Gao +11

We present the Hyper Millennium (HM) simulation, an extremely large cosmological simulation designed to support next-generation galaxy surveys. The simulation follows 4.2 trillion…

astro-ph.GA2025★ 2 cited

JWST Discovery of Strong Lensing from a Galaxy Cluster at Cosmic Noon: Giant Arcs and a Highly Concentrated Core of XLSSC 122

Kyle Finner, Sangjun Cha, Zachary P. Scofield +9

Our observations with the James Webb Space Telescope have made the remarkable discovery of strong gravitational lensing arcs from XLSSC 122 () - setting the record for the…

astro-ph.GA2025★ 1 cited

MrMARTIAN: A Multi-resolution Mass Reconstruction Algorithm Combining Free-form and Analytic Components

Sangjun Cha, M. James Jee

We present (Multi-resolution MAximum-entropy Reconstruction Technique Integrating Analytic Node), a new hybrid strong lensing (SL) modeling algorithm. By incorpor…

astro-ph.GA2025

Is Earendel a Star?: Investigating the Sunrise Arc Using JWST Strong and Weak Gravitational Lensing Analyses

Zachary P. Scofield, M. James Jee, Sangjun Cha +1

The galaxy cluster WHL J013719.8-08284 at exhibits a strong-lensing feature known as the Sunrise Arc, which hosts the candidate star Earendel at , the mo…

astro-ph.GA2025★ 18 cited

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

Sangjun Cha, Boseong Young Cho, Hyungjin Joo +5

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 im…

astro-ph.GA2025★ 1 cited

A stellar dynamical mass measurement of an inactive black hole at redshift 2

Andrew B. Newman, Meng Gu, Sirio Belli +34

Supermassive black holes and their host galaxies grow together over time, producing correlations between the black hole mass and various galaxy properties. Determining the evolutio…

astro-ph.CO2025★ 8 cited

Cosmology with supernova Encore in the strong lensing cluster MACS J01382155: photometry, cluster members, and lens mass model

S. Ertl, S. H. Suyu, S. Schuldt +23

The strongly lensed Supernova (SN) Encore at a redshift of , discovered behind the galaxy cluster MACS J01382155 at , provides a rare opportunity for time-de…

astro-ph.GA2024★ 4 cited

Weak-lensing Mass Reconstruction of Galaxy Clusters with a Convolutional Neural Network -- II: Application to Next-Generation Wide-Field Surveys

Sangjun Cha, M. James Jee, Sungwook E. Hong +3

Traditional weak-lensing mass reconstruction techniques suffer from various artifacts, including noise amplification and the mass-sheet degeneracy. In Hong et al. (2021), we demons…

astro-ph.CO2024★ 9 cited

SN H0pe: The First Measurement of from a Multiply-Imaged Type Ia Supernova, Discovered by JWST

Massimo Pascale, Brenda L. Frye, Justin D. R. Pierel +21

The first James Webb Space Telescope ({\it JWST}) Near InfraRed Camera (NIRCam) imaging in the field of the galaxy cluster PLCK G165.7+67.0 () uncovered a Type Ia supernova…

astro-ph.GA2023★ 8 cited

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

Kim HyeongHan, Hyejeon Cho, M. James Jee +15

The galaxy cluster Abell 746 (A746; =0.214), featuring a double radio relic system, two isolated radio relics, a possible radio halo, disturbed V-shaped X-ray emission, and intr…

astro-ph.CO2023★ 21 cited

Weak-Lensing Detection of Intracluster Filaments in the Coma Cluster

Kim HyeongHan, M. James Jee, Sangjun Cha +1

Our concordance cosmological model predicts that galaxy clusters grow at the intersection of filaments structuring the cosmic web stretching tens of Mega parsecs. Although this hyp…