SImulating the Environment where Globular clusters Emerged

30/12/2022

Hydrodynamical simulations are formidable tools to study the behaviour of astronomical fluids.
When matched to N-body solvers, they also allow one to model complex phenomena, such as star formation and stellar dynamics.
In the “SImulating the Environment where Globular clusters Emerged” project, we use cosmological hydrodynamical
simulations to investigate the sites where the first bound stellar clusters originate.

We also run non-cosmological simulations of isolated proto-globular clusters, to model the origin of their multiple stellar populations.

 

1) Cosmological simulations including the feedback of individual stars

Thanks to the recent, first observational studies of the progenitors of globular clusters (GCs) at high redshift, star clusters have regained significant interest also from a cosmological perspective.
At the present day, resolving the formation of star clusters is one of the most ambitious goals in galaxy formation models.
Most stars form in clustered environments and both young massive clusters (YMCs) and old GCs are ubiquitous
in local galaxies. GCs are typically old systems, with ages above a few Gyr and sizes of a few parsecs, similar to the ones of young
clusters found in the Milky Way (MW) and other local star-forming galaxies. In the light of this evidence, it is
natural to suppose that old GCs represent the surviving subgroup of a larger population of young, dense stellar aggregates that
formed at high redshift.

Studying the origin of GCs in a cosmological framework is a multi-disciplinary task that requires knowledge in separate fields of
astronomy. In fact, the evolution of clusters results from the combination of various processes, including star formation, stellar
evolution, internal, collisional mechanisms such as two-body relaxation and external ones, such as tidal shocks.
Galaxy formation simulations include an accurate description of basic physical processes and are well-suited for studying in detail
the evolution of star clusters.

In the SIEGE project, we model the feedback of single stars at sub-pc resolution in a cosmological simulation. 

More to come soon