A first GLIMPSE into star-cluster populations across cosmic time

We present the first sample of 218 high-redshift (z>0.5) star clusters, detected with JWST/NIRCam in 78 magnified galaxies from different galaxy cluster fields. The majority of the systems (∼ 60 %) are observed in the very deep NIRCam observations of the cluster AbellS1063 (GLIMPSE program), showing the power that deep observations, combined with lensing, has to reveal these primordial stellar structures. We performed simultaneous size--flux estimates in all available NIRCam filters and spectral energy distribution (SED) fitting analysis to recover star-cluster physical properties. All star-cluster candidates have very high magnification (μ>10). Star clusters and clumps show similar ages and redshift distributions, although noticeable differences are seen in their masses, sizes and stellar surface densities inherent to the lack of resolution in the latter group. We reconstructed the formation redshift of star clusters and find that the vast majority of the observed star clusters show young ages ($