Chemical evolution of the Galaxy based on the oscillatory star formation history

We model the star formation history (SFH) and the chemical evolution of the Galactic disk by combining an infall model and a limit-cycle model of the interstellar medium (ISM). Recent observations have shown that the SFH of t he Galactic disk violently variates or oscillates. We model the oscillatory SFH based on the limit-cycle behavior of the fractional masses of three co mponents of the ISM. The observed period of the oscillation (similar to1 Gy r) is reproduced within the natural parameter range. This means that we can interpret the oscillatory SFH as the limit-cycle behavior of the ISM. We t hen test the chemical evolution of stars and gas in the framework of the li mit-cycle model since the oscillatory behavior of the SFH may cause an osci llatory evolution of the metallicity. We find, however, that the oscillator y behavior of metallicity is not prominent because the metallicity reflects the past integrated SFH. This indicates that the metallicity cannot be use d to distinguish an oscillatory SFH from one without oscillations.