Spatially resolving the spectral properties of lensed galaxies at z>3

Despite the progress made with state-of-the-art instrumentation, spatially resolved studies of galaxy spectral properties at redshifts z>3 are still challenging. The typical scale over which intermediate/high-redshift galaxies can be observed is of a few kpc, which is comparable to the size of the entire galaxy. In contrast, lensing fields can offer an excellent solution to circumvent this problem, allowing us to spatially resolve galaxy substructures down to sizes of ~0.1 kpc and at the same time reach faint fluxes in a short amount of observing time. In this talk, I will present the first results of our studies of resolved galaxy spectral properties at z>3, based on the analysis of VLT/MUSE WFM+AO observations in lensing fields. I will show how the combination of MUSE/AO and HST data provides important information on the star formation process and galaxy ISM dynamics, and discuss the complementarity of our results with future spectroscopic studies with JWST.