Globular Clusters in the Galaxy Cluster MACS0416 at z = 0.397
Abstract
We present a photometric analysis of globular clusters (GCs) in the massive galaxy cluster MACS J0416.1-2403 (z = 0.397) using deep JWST/NIRCam imaging from the PEARLS program. PSF photometry was performed in the short wavelength filters F090W, F115W, F150W, and F200W, yielding a catalog of approximately 3 x 10^3 unresolved, point-like sources consistent with a GC population. Artificial star tests indicate 80% completeness at F200W = 30.36 mag. The color-magnitude diagrams show a narrow GC sequence well reproduced by PARSEC single-stellar-population models spanning ages of 5-9 Gyr and metallicities from [M/H] = -2.0 to +0.2, consistent with evolved GC systems at this redshift. The globular cluster luminosity function (GCLF) follows a log-normal form truncated by incompleteness at the faint end. The brightest sources extend slightly beyond the locus of classical GCs, suggesting a small number of UCD-like systems or stripped nuclei, while the bulk of the population exhibits the luminosities and colors expected for mature globular clusters at z ~ 0.4.
Cite
@article{arxiv.2508.03883,
title = {Globular Clusters in the Galaxy Cluster MACS0416 at z = 0.397},
author = {Jessica M. Berkheimer and Rogier A. Windhorst and William E. Harris and Anton M. Koekemoer and Timothy Carleton and Seth H. Cohen and Rolf A. Jansen and Dan Coe and Jose Diego and Christopher J. Conselice and Simon P. Driver and Brenda L. Frye and Norman A. Grogin and Kate Hartman and Tyler R. Hinrichs and Benne W. Holwerda and Patrick S. Kamieneski and Kaitlyn E. Keatley and William C. Keel and Ray A. Lucas and Madeline A. Marshall and Mario Nonino and Nor Pirzkal and Massimo Ricotti and Clayton D. Robertson and Aaron Robotham and Russell E. Ryan, and Jake Summers and Christopher N. A. Willmer and Haojing Yan},
journal= {arXiv preprint arXiv:2508.03883},
year = {2025}
}
Comments
14 pages, 8 figures, 2 tables