PhD ceremony Simone Veronese

On Tuesday 25 November 2025, Simone Veronese defends his thesis called Tracing gas accretion and feedback in nearby galaxies using ultra-deep neutral hydrogen MeerKAT observations

Summary of his thesis:
We do not know how galaxies evolved from the initial dark-matter distribution to the diverse structures that we observe at the present day. It is thought that gas accretion from the cosmic web and feedback from supernovae and active galactic nuclei (AGN) dominate galaxy evolution. Both accretion and feedback can be traced in the local Universe by looking at the emission from the neutral atomic hydrogen (HI). In my thesis I present results coming from the best observations of the HI in 30 nearby galaxies available to date, acquired by the MeerKAT telescope in South Africa. I found little evidence for the presence of HI associated with gas accretion in the local Universe, posing challenges to the predictions by current cosmological simulations. I also revealed that the distribution of the HI in outermost regions of a galaxy differs from the predictions of theoretical models. As for the impact of the stellar and AGN feedback, my work showed that even a gentle AGN activity might drastically affect the evolution of a galaxy.

Link to Simone's thesis

If available, you can follow the PhD ceremony via this livestream