Programma: PRIN
Responsabile scientifico per il dipartimento: Carlo Nipoti
Struttura principale: DIFA
Data inizio e data fine: dal 28/09/2023 al 28/09/2025
Cluster stellari: chiavi per comprendere galassie e stelle
Il progetto simula l’evoluzione dei cluster globulari nel contesto cosmologico, integrando dati osservativi e modelli teorici per studiare struttura, chimica e dinamica, formando giovani ricercatori.
Star Clusters: Keys to Understanding Galaxies and Stars
The project simulates globular cluster evolution in a cosmological context, integrating observations and models to study structure, chemistry, and dynamics, while training young researchers.
Abstract
Globular clusters (GCs), and star clusters in general, stand at the crossroads between galaxies and single stars.Stellar clusters are key to the formation of stars, as increasing evidence suggests that most stars (if not all) are born in various formsof aggregates, such as groups, clusters, or hierarchies of these. On the other hand, star clusters strongly affect their surroundingenvironment by driving energetic super-bubbles of hot gas that trigger galactic outflows. Moreover, a large fraction of stars invarious galactic components, such as the Milky Way Halo and discs, originated from dissolved star clusters. In the past, star clustersand GCs were regarded as self-standing entities whose formation, evolution, and possible dissolution were viewed in relativeisolation, considering their host galaxy as the background source of a passive tidal field. On the other hand, galaxy formation modelshave normally described star clusters as macroscopic particles, typically representing one or more of them and ignoring theirunderlying substructure.In any modern attempt to model star cluster formation and evolution in a galactic and cosmological context, such separation ofgalaxy and cluster evolution into self-standing categories is no longer viable.So far, there have been very few attempts to model the formation of GCs within a cosmological context, with sufficient resolution todescribe realistically the evolution of their sub-components. Moreover, no one ever has attempted to study self-consistently theirformation and subsequent long-term dynamical evolution to the present day.Following up on a state-of-the-art, existing set of high-resolution cosmological simulations, we aim to design a new model of aMilky-Way halo with unprecedented features. The new simulations will have sub-parsec resolution down to redshift z~2 and will beamong the first in a fully cosmological framework including the feedback of individual stars. At later epochs, the evolution of thesystem will be followed by means of a cosmological, pure N-body simulation, which will be enough for a realistic description of thedynamical evolution of its sub-systems, in particular the GCs. We will compare the structural properties of the simulated clusters (i.e.magnitudes, density and sizes) with a wealth of multiwavelength observational data of the ancestors of present-day GCs in lensedfields. We will create lensed mock images of the simulated objects, a process that will be key for a reliable comparison between ourhigh-level, proprietary data and simulations. We will study the chemical abundance pattern and the kinematical properties of thesimulated clusters and compare them with local GCs. Our project, which involves a wide range of theoretical and observationalexpertise, is strategically important for training young researchers in highly competitive fields, which will dominate the scientificscope of present and future observing facilities.