THE PRODUCTION AND DEPLETION RATES IN MODELS FOR THE CHEMICAL EVOLUTION OF THE GALAXY

The stellar production and depletion rates associated with a given met al are derived, to be used in the general equation for the mass conser vation in models of the chemical evolution of the Galaxy. It is shown that the metal conservation equation of Tinsley (1980) can be recovere d with the adoption of some simplifying hypotheses, such as neglecting the metals stored in the remnants. With the derived equation, we show that the total mass of a given metal can be affected by the hypothese s usually made. For the bulk of metals, we find that their total mass can be increased up to an order of magnitude relative to the expected mass of metals as given by Tinsley (1980).