Dust evolution across cosmic times as seen through DUSTY-GAEA

For many decades, dust has been recognised as an important ingredient in galaxy formation and evolution. This paper presents a novel self-consistent implementation of dust formation by stars, destruction by supernova shocks and hot gas, and growth within the dense interstellar medium (ISM) in the state-of-the-art GAEA galaxy formation model. Our new model DUSTY-GAEA is able to reproduce the dust build-up as a function of stellar mass out to z ∼ 6, the scaling relations between the dust-to-gas and dust-to-metal ratios and the stellar mass and metallicity in the local Universe, and the dust mass function both in the local Universe and out to z ∼ 1. In the framework of our model, dust growth dominates the cosmic dust budget out to z ∼ 8, and we find that observational constraints beyond the local Universe can be reproduced only when assuming such efficient dust growth in the dense ISM. Nevertheless, reproducing the estimated number densities of dust-rich galaxies at higher redshifts remains challenging, as also found in independent theoretical work. We discuss our model predictions in comparison with both observational data and independent theoretical efforts, and we highlight how further observational constraints at high redshifts would help constrain dust models.