Chemical Evolution via Dilution of an Initial Reservoir of Heavy Elements

As a possible analog to the type of environment that might have produced the first low-mass metal-containing stars, a model is outlined in which a reservoir of gas containing the first metals begins forming stars upon an inflow of metal-free gas from a surrounding environment. The mass of gas in the reservoir is assumed to initially increase, reach a maximum, and then follow an exponential decline. The stellar metallicity distribution brought about is an example of chemical evolution via dilution of an initial source of metals.