Research
My research focuses on the formation and evolution of galaxies, with a specific emphasis on the structural assembly of Milky Way-sized systems. By utilizing state-of-the-art cosmological hydrodynamical simulations, I aim to bridge the gap between high-redshift observations, such as those from the James Webb Space Telescope (JWST) and ALMA, and the detailed galactic archeology of our own local Universe.
The Fate of Primordial Discs
One of the major pillars of my research is exploring the longevity and evolution of the first (kinematically cold) stellar discs. Using the high-resolution GigaEris simulation, I investigate(d) how these primordial structures survive or transform through the chaotic environments of the early universe (z > 4). Understanding whether these early discs persist to form the modern “thin disc” of galaxies like the Milky Way is critical for a complete theory of galactic morphology.
Work done in Phoebos complements this work by showing that at z>8, a small fraction of galaxies host already rotationally supported discs. These discs occur almost exclusively in the highest-mass haloes. They exhibit lower gas temperatures, younger stellar populations, and larger halo sizes and masses compared to non-disc systems. Understanding whether these early discs persist to form the modern thin discs of galaxies like the Milky Way is crucial for a complete theory of galactic morphology.
Star Clusters
Another major pillar of my work are the dense stellar environments found at the hearts of galaxies, but also within the filaments. I explore:
- Proto-Globular Clusters: Studying the birth and migration of early star clusters in the circum-galactic medium.
- High-Redshift Dense Clusters: Investigating how galactic disc fragmentation and gravitational collapse along filaments at redshifts above seven can form ultracompact clusters. These dense clusters can also seed intermediate-mass black holes, which may later grow into supermassive black holes. Observations show that many early galaxies host extremely dense, compact stellar clusters at redshifts above six, and our simulations reproduce this behavior both within discs and along filaments.
- Feedback in Dense Clusters: Dense stellar clusters modify the local impact of feedback. Clustered supernovae inject more momentum than isolated events, scaling superlinearly with cluster size. Concentrated radiation, winds, and ionization fields boost local heating and gas pressure. Feedback is more efficient locally, while large-scale effects may be limited if energy is trapped. These processes must be captured to fully understand early galaxy growth.
- Origin of the Nuclear Star Cluster: identifying a hybrid formation scenario for the Milky Way’s NSC. Using high-resolution simulations, I have shown that the NSC is built both from the dynamical in-spiral of primordial globular clusters and local in-situ star formation fueled by gas channeled to the center by early stellar bars. This process is intrinsically linked to the formation of the Nuclear Stellar Ring at z > 4.
Intermediate-Mass Black Holes (IMBHs)
Intermediate-mass black holes are often seen as the missing link in black hole evolution and a recurring focus of my simulations. I investigate the existence of wandering IMBHs within Milky Way-mass galaxies, exploring whether these elusive objects reside in stellar halos or remain hidden within massive star clusters. I also examine the role of dense star clusters in feeding supermassive black holes, connecting cluster evolution to black hole growth. You could say this part of my work is a bit of a mid-game side quest.