Ricerc@Sapienza

Recent deep observations of the young Universe (z > 4) by the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered that normal star forming galaxies already show a non negligible amount of dust in their interstellar medium, which is supposed to significantly obscure the UV light emitted by their young stars and to affect their observed colours. As this sample will certainly increase with the next generation of high-redshift surveys, robust theoretical models will become crucial to interpret the impact of dusty galaxies on the early phases of star formation and on the reionization and thermal history of the intergalactic medium. Our research aims to address the following three key questions:
(i) Understand how dust is produced at cosmic dawn by the first generation of stars (Population III) and its role in driving the transition between massive Population III and Population II stars, with masses comparable to the ones observed in the Local Universe.
(ii) Elucidate the effect of dust on the rest-frame UV emission of the first galaxies, upon which most of their physical properties are derived.
(iii) Estimate the fraction of dust-obscured galaxies and evaluate their role in the metal enrichment and reionization of the intergalactic medium.

In the last years we developed a unique combination of theoretical models exploring dust nucleation in supernova ejecta as well as numerical simulations of young dusty galaxies constrained by presently available ALMA and Hubble Space Telescope observations. We constantly upgrade our models by improving their physics, to make them ready for the next fresh data provided by new large surveys planned with ALMA and by the forthcoming launch of the James Webb Space Telescope. The funding requested by our team will principally allow the dissemination of our results by supporting exchange activities with external collaborators, and the participation to international conferences and European meetings.