Abstract
Assuming that both the star formation rate and the gas velocity dispersion in a disk galaxy are regulated by the stellar energy injection, a self-consistent chemical evolution model can be constructed. The star formation rate and the disk thickness are no longer free parameters, but they are controlled by the feedback between gas and stars. Given that the gas pressure is a function of the gravitational field, such a feedback results in a star formation rate that is also dependent on the total mass surface density. Here the authors present preliminary results, for the Milky Way, assuming that the galactic mass grows by primordial infall and that the gas relaxes to an isothermal disk in hydrostatic equilibrium. The nucleosynthesis parameters and the infall rates are taken as in Matteucci and François (1989). The star formation rate is adapted from the self-regulated model discussed by Franco and Shore (1984), and the initial mass function is taken from Scalo (1986). The observed elemental gradients, the age-metallicity relation for the solar neighborhood, the G-dwarf chemical distribution, and the present day disk surface gas density distribution, are reasonably well reproduced by the model.
