Chemical evolution of the Galaxy at the initial rapid-collapse phase

The dynamical and chemical evolution of the Galaxy are studied simultaneously in order to search for correlation between the phase of early collapse and the amount of metals produced by nucleosynthesis in newly formed stars. Simple equations are derived for the dynamical evolution, accounting for the experimental values of axial ratio and semimajor axis of the Galaxy. A particular stellar birth-rate function is adopted. The boundary condition is chosen that at the present time the birth-rate function should coincide with Salpeter's (1955). The resulting equations were solved numerically, and the effect of various parameters on gas density and metallicity is studied