High resolution spectroscopy of Red Giant Branch stars and the chemical evolution of the Fornax dwarf spheroidal galaxy

From VLT-FLAMES high-resolution spectra, we determine the abundances of several α, iron-peak and neutron-capture elements in 47 Red Giant Branch stars in the Fornax dwarf spheroidal galaxy. We confirm that SNe Ia started to contribute to the chemical enrichment of Fornax at [Fe/H] between --2.0 and --1.8 dex. Combining these abundances with accurate age estimates, we date the onset of SNe Ia to ≈ 12--10 Gyrs ago. Our results are compatible with an initial mass function that lacks the most massive stars and with a star formation going on throughout the whole history of Fornax