CMDFs (left panel) and temporal evolution of the gas phase metallicity Z (right panel) for models with different prescriptions for the infall and outflow. The grey shaded area in the left panel indicates the region reachable only by models with outflows and assuming a yield per stellar generation y_z = 0.0301 (as in Spitoni et al. 2017). The solid light blue line shows the results of a closed-box model obtained assuming a lower value for the yield per stellar generation (y_z ∼ 0.005), as in Fig. 1 of Greener et al. (2021).