Star Formation History of the WLM dIrr

The HI-gas-rich, WLM dwarf irregular galaxy has been forming stars for at least 11 Gyr. It is one of the nearest examples of isolated, metal-poor star formation in the Local Group, and contains a single globular cluster. We explore the spatial distribution, ages, and chemical evolution of its stellar population, particularly in the metal-poor halo, compared to the rotating bulge/disk system. We present an extensive imaging survey in BVRI filters (based largely on archival data) as a supplement to previous spectroscopy of a limited sample of giants and supergiants. In addition, a Washington-C survey has been carried out along the rotation (minor) axis into the halo, where the Washington color, C-T1(where the R-filter can be used) can be up to 3 times more sensitive to metallicity than V-I for giant-branch populations.