Mergers all the way down: building massive star clusters in dwarf galaxy starbursts.

by Dr Natalia Lahén (MPA Garching)

Friday 29 Aug 2025, 10:30 → 11:30 Europe/Stockholm

FC61 (AlbaNova Main Building)

JWST has revealed that massive star clusters, the possible progenitors
of globular clusters (GCs), formed with high mean stellar surface
densities. The internal structure and kinematics of these proto-GCs,
however, still remain a mystery. A number of phenomena only possible at
such high densities have been theorized to occur: for instance, massive
stars and black holes can grow in mass due to collisions, and chemical
self-enrichment can occur due to the deep gravitational well of the
massive cluster. In this talk I will explore the formation of star
clusters in such extreme galactic environments by introducing the
results of star-by-star hydrodynamical simulations of low-metallicity
dwarf galaxy starbursts. The simulations account for a multiphase
interstellar medium, stellar radiation, winds and supernovae, and
accurate small-scale gravitational dynamics near massive stars. The
latest simulation includes prescriptions for stellar collisions and
tidal disruption events by black holes. I will present results for the
galactic population of star clusters extending to the proto-GC regime,
and demonstrate that the hierarchical assembly of the most massive
clusters leaves a kinematic imprint in their stellar populations.