MassiveBlackPS Simulation Links Isolated Wallflower Clusters at z~7.6 to Milky Way Globular Cluster Progenitors

The arXiv preprint (2606.27426) from Floor Van Donkelaar and colleagues examines star-forming clusters at z7.6, distinguishing gravitational-instability products inside galactic discs from filament-born cosmic wallflowers. Kinematic analysis reveals wallflowers occupy a lower-rotation regime, with gas-rich members overlapping globular-cluster parameter space after accounting for surface density. This separation implies formation environment imprints lasting dynamical signatures rather than being erased by later evolution. Standard globular-cluster formation scenarios emphasize either in-situ disc fragmentation or accretion of dwarf-galaxy nuclei. The wallflower channel introduces a third pathway in which low-angular-momentum, filament-fed systems lose rotation through dynamical heating and tidal stripping, naturally explaining the pressure-supported, old populations seen today. The denser, still-rotating wallflowers are instead flagged as possible massive black-hole seed precursors, linking cluster and quasar seeding problems. Context from the EAGLE and IllustrisTNG suites shows similar filamentary objects, yet those runs lacked the mass resolution to track internal stellar kinematics at z>7. The present result therefore supplies a falsifiable prediction: JWST/NIRSpec integral-field spectroscopy should detect a subpopulation of compact, low-v/σ sources at z7–8 whose gas fractions exceed 30 percent. Confirmation would reframe globular clusters as relics of early large-scale structure rather than purely galactic by-products.