Fig. 3. Results of the chemical evolution model for the Milky Way disk and comparison to observations. In all panels, results are shown at three different epochs (dotted curves: 1 Gyr, dashed curves: 5 Gyr, solid curves: 13.5 Gyr). The latter are to be compared to observations of present-day profiles in the Milky Way disk, shown as shaded regions in first three panels and within error bars in the lower panel. In all panels, the error bar at = 8 kpc indicates observed quantities in the solar neighborhood. References for data are given in BP99.