Progetti di ricerca

The currently favoured Lambda-Cold-Dark-Matter (ΛCDM) cosmological model makes specific predictions about the abundance, structure and clustering of dark matter halos (DMHs), the sites where galaxies form. These predictions are accurate at describing large scale observations. On smaller scales, the agreement between ΛCDM… Leggi tutto and observations of dwarf galaxies is unclear because (i) the structure of DMHs depends on particularities of different galaxy formation models, and (ii) observations of dwarfs suffer from sizable uncertainties. Is ΛCDM successful on small scales? A definite answer to this major open question may either reveal the nature of DM or change dramatically our understanding of structure formation in the Universe. My research will deliver the foundations to probe ΛCDM on unprecedented small scales by exploiting a fundamental prediction of the model: the existence of nearby DM-dominated “dark” galaxies (so-called RELHICs). RELHICs are pristine collapsed DMHs that contain sufficient gas leftover from the epoch of reionization to recombine and emit radiation that can be observed in 21 cm (or recombination lines) but without becoming self-shielding and forming stars. Firstly, I will develop and analyse high-resolution hydrodynamical simulations performed with state-of-the-art numerical codes that include cutting-edge galaxy formation and radiative-transfer (RT) models to predict the abundance and clustering of RELHICs. Secondly, I will design robust survey strategies targeted at detecting RELHICs with current and upcoming observing facilities (e.g., ALMA, FAST, MEERKAT, WALLABY). The detection and characterization of REHICs will offer an unprecedented and clean probe to ΛCDM on scales that have not yet been probed. My extensive expertise in numerical simulations, cosmology and galaxy formation, combined with that of Prof. Michele Fumagalli in RT and physics of the interstellar medium will enable me to materialize my predictions into observational probes

Galaxies reside within a web of gas that feeds the formation of new stars. Following star formation, galaxies eject some of their gas reservoir back into this cosmic web. This proposal addresses the fundamental questions of how these inflows and… Leggi tutto outflows regulate the evolution of galaxies. My research team will tackle two key problems: 1) how gas accretion regulates the build-up of galaxies; 2) how efficiently outflows are in removing gas from star-forming regions. To characterise these flows across five billion years of cosmic history, we will pursue cutting-edge research on the halo gas, which is the material around the central galaxies, within dark matter halos. We will focus on scales ranging from a few kiloparsecs, where outflows originate, up to hundreds of kiloparsecs from galaxies, where inflows and outflows have visible impacts on halos. We will attack this problem using both simulations and observations with the largest telescopes on the ground and in space. With novel applications of absorption spectroscopy, we will gain a new vantage point on the astrophysics of these gas flows. Exploiting unprecedented datasets that I am currently assembling thanks to ground-breaking developments in instrumentation, we will directly connect the properties of halo gas to those of the central galaxies, investigating the impact