Paper detail

Observed cosmic evolution of galaxy dust properties with metallicity and tensions with models

The dust abundance of the interstellar medium plays an important role in galaxy physics, the chemical evolution of matter and the absorption and re-emission of stellar light. The last years have seen a surge in observational and theoretical studies constraining the dust-abundance of galaxies up to $z\sim5$. In this work we gather the latest observational measurements (with a focus on absorption studies covering metallicities in the range $6.8 < 12 + \log{(O/H)}<9$) and theoretical predictions (from six different galaxy formation models) for the dust-to-gas (DTG) and dust-to-metal (DTM) ratio of galaxies. The observed trend between DTG and DTM and gas-phase metallicity can be described by a linear relation and shows no evolution from $0<z<5$. Importantly, the fit to the DTG-metallicity relation provides a refined tool for robust dust-based gas mass estimates inferred from millimeter dust-continuum observations. The lack of evolution in the observed relations are indicative of a quickly reached balance (already when the Universe was 1.2 Gyr old) between the formation and destruction of dust and a constant timescale for star-formation at fixed metallicities over cosmic time. None of the models is able to reproduce the observed trends over the entire range in metallicity and redshift probed. The comparison between models and simulations furthermore rules out some of the current implementations for the growth and destruction of dust in galaxy formation models and places tight constraints on the predicted timescale for star-formation.