Stars and dust in the first Gyr of the Universe

Abstract

My thesis uses multi-wavelength data of distant (high-redshift) galaxies, combining the galaxy parameters estimated by SED fitting with the study of cosmic dust. It relates the dust attenuation to the stellar mass of star-forming galaxies and its evolution with redshift. The dust attenuation vs stellar mass data, separated in redshift bins, was modelled by a single parameter linear function, assuming a nonzero constant apparent dust attenuation for low mass galaxies. The best-fitting parameter of this model is used to study the redshift evolution of the cosmic dust attenuation and agrees with results from the literature. This work also gives evidence to a redshift evolution of the dust attenuation-stellar mass relationship, as is suggested by recent works in the highest redshift range. We continue the work of Burgarella et al. (2020) using similar methods on the ALPINE galaxy sample, which provides a measurement of the [CII]158um line of 4.5 < z < 6.5 galaxies. We perform SED fitting on the ALPINE galaxies with CIGALE, aiming to determine the galaxy parameters. Using the results of the SED fitting, we extend the results of Burgarella et al. on several key diagnostic diagrams to study the evolution of galaxies and the buildup of dust through cosmic times.Finally, we mention the possibility of extending the work of our first paper to create realistic mock catalogues of galaxies. Next, we plan to continue working with chemical evolution models, similarly to Nanni et al. (2020). We also plan to continue working with early-Universe galaxies, so more observations with ALMA are expected, and further continuation of our current projects on new datasets is anticipated