Modeling Star Formation History and Chemical Evolution of Resolved Galaxies

Abstract

We present a new numerical model (SMART) for deriving the star formation history and chemical evolution from the color-magnitude diagrams of resolved stars in galaxies. Our model differs from previous models in that it generates simulated color-magnitude diagrams with the metal enrichment law calculated from the galactic chemical evolution model. Hence, our model is free from the problem of age-metallicity degeneracy and provides us with information on the chemical enrichment history as well as the star formation history of galaxies. We have tested our model on artificial galaxies having different star formation histories and on the Local Group dwarf irregular galaxy IC 1613. Our model successfully reproduces the star formation history and chemical evolution of the artificial galaxies. The star formation and metal enrichment histories of IC 1613 derived in this study are consistent with those in previous studies. We also present the elemental abundance ratios for IC 1613 predicted by our model. Our model is expected to be useful for understanding not only the star formation history but also the chemical evolution of nearby galaxies.