JWST NIRCam Observations of the Globular Cluster Population of RXJ 2129.7+0005

Abstract We present an analysis of the globular cluster (GC) population in the galaxy cluster RXJ 2129.7+0005 ( z = 0.234) based on JWST NIRCam imaging in three filters: F115W, F150W, and F200W. We use this material to provide a detailed look at the color–magnitude distribution of the GCs and their spatial distribution around the central giant galaxy. We identified 3160 GC candidates brighter than F150W = 29.5, and assessed photometric completeness through artificial star tests. We determined that the GCs follow a radial power-law distribution with an index of 1.58 ± 0.04, with the redder GCs exhibiting a slightly greater central concentration. Their spatial distribution is also highly elliptical, closely following the shape of the brightest cluster galaxy halo light.