Description
JWST has recently revealed gravitationally lensed systems of high-z, star-cluster-like objects, such as the Cosmic Gems (z ~ 10.2) and Firefly Sparkle (z ~ 8.3). In this early epoch of galaxy assembly, these massive stellar clusters are thought to be the progenitors of present-day globular clusters (GCs). The emergence, early properties, and contribution to galaxy formation of GC-like objects in this era are, however, not well understood. To study these objects in a fully cosmological context, we utilize a cosmological zoom-in simulation of a Milky-Way-like halo using the LYRA model: an AREPO-based, ultra-high resolution (4 M_sun), multiphase interstellar medium implementation, featuring resolved blast waves of individual supernovae. Focusing on z > 8, we present the range of formation scenarios and resultant properties of the massive stellar clusters that are predicted by the simulation. We additionally compare the stellar clusters that form within the main galaxy to its satellite galaxies of similar stellar mass, and investigate whether it is possible to observationally distinguish them from one another. Finally, we put our findings in the context of JWST observations of high-z star cluster systems.
