REDEEMING

Understanding the properties and evolution of interstellar dust is a key to our knowledge of galaxy evolution. A promising way to progress in this field is to model the dust properties of galaxies at different stages of their evolution (i.e. at different metallicities). Contemporary dust models are however constrained solely by the observations of the Milky Way (MW), specific to Solar metallicity systems. Their current application to lower-metallicity objects is thus biasing our knowledge of galaxy evolution. Fortunately, we now have, in the Large and Small Magellanic Clouds (LMC and SMC), the set of observations necessary to properly constrain the grain properties (abundance, composition, size distribution), similarly to what is done in the MW: the emission, extinction and elemental depletions of their diffuse interstellar medium. It is therefore timely to take this opportunity. We propose to hire two postdoctoral researchers at DAp and IRAP, to simultaneously model the dust properties in the MW, LMC and SMC, by inferring metallicity-dependent grain properties. We will take particular care in estimating the different sources of observational and experimental uncertainties and propagate them through the Bayesian inference of the dust parameters. We will consequently deliver the first metallicity-dependent, probabilistic, fully-constrained dust model. This model will allow the community to: (i) more reliably interpret observations of galaxies; (ii) benchmark cosmic dust evolution models; and (iii) improve the accuracy of numerical simulations of the star formation process and of galaxy evolution.