Research

My research focuses on the formation and evolution of galaxies at high redshift, with a particular emphasis on how structure emerges across scales, from galactic discs down to compact stellar systems. Using state-of-the-art cosmological simulations, I connect early galaxy assembly to observations from the JWST era, linking resolved high-redshift structures to the present-day Universe.

Star Clusters across Environments

A central pillar of my research focuses on the formation of dense stellar systems at high redshift, both within galaxies and in their surrounding circumgalactic medium. These systems provide a direct link between gas dynamics, star formation, and galaxy assembly, and allow us to connect small-scale physics to cosmological (stellar) structure formation. Together, this work places star cluster formation into a cosmological context, connecting their birth environments, internal dynamics, and long-term evolution to the assembly of galaxies across cosmic time.

Key aspects of my work on this topic include:

• Kinematics and Evolutionary Pathways:
  The formation environment leaves a clear imprint on cluster dynamics. Cosmic wallflowers, i.e. star clusters formed in the circumgalactic medium, span a broad range in rotational support, providing a direct link between their birth conditions and internal kinematics. Lower-density, weakly rotating systems overlap with the observed local globular cluster population, suggesting they are natural proto-globular cluster candidates. In contrast, denser and more rapidly rotating systems are more likely to undergo runaway collapse, forming intermediate-mass black hole seeds.

• Cluster Formation across Environments:
  Cluster formation is not limited to a single channel. Within galactic discs, dense clusters arise through gravitational fragmentation and gas inflows at high redshift. In parallel, star-forming structures in the circumgalactic medium are studied using simulations such as the FABLE runs and MassiveblackPS, where feedback and environment regulate their formation, migration, and survival.

• Feedback, Migration, and Nuclear Star Cluster Formation:
  Dense stellar clusters likely modify the efficiency and impact of feedback, with supernovae, radiation, and stellar winds coupling more strongly to the surrounding gas. At the same time, their subsequent evolution is governed by migration and dynamical interactions within the host galaxy. This for example can lead to a hybrid formation pathway for nuclear star clusters, in which early star clusters migrate inward while in-situ star formation is fueled by gas inflows. This process is closely linked to the emergence of nuclear structures, such as stellar rings, at high redshift, and connects cluster evolution directly to the build-up of galactic centres.

Also, a recurring theme in my work is the role of dense stellar systems is the formation and growth of intermediate-mass black holes. More broadly, I try to connect cluster evolution to black hole growth and galaxy evolution, including the role of clusters in feeding central black holes and shaping nuclear regions. This provides a link between small-scale dynamical processes and the large-scale assembly of galaxies.

The Assembly and Survival of Galactic Discs

A second pillar of my work is understanding how the first galactic discs form and evolve in the early Universe. Using simulations such as GigaEris and Phoebos, I investigate when and where kinematically cold, rotationally supported discs emerge, and how they are affected by feedback, mergers, and their surrounding environment.

In GigaEris, I explored the fate of primordial discs at z > 4, testing whether these early structures survive till present day or are transformed into other structures like the bulge. Complementary work in Phoebos shows that already at z > 8, a subset of galaxies host rotationally supported discs, primarily in the most massive haloes. These systems are systematically colder, younger, and more extended than non-disc galaxies. Together, this work constrains the conditions under which stable discs can form and persist, providing a direct link to the origin of present-day thin discs, but also discusses what it means to be a disc galaxy.