PI: Ryan Leaman, University of Victoria, firstname.lastname@example.org
Address: Physics Department, PO Box 3055, STN CSC, Victoria, B. C. V8W 3P6, Canada
CoI: Joanne Hughes, Seattle University
CoI: Andrew Cole, University of Tasmania
CoI: Kim Venn, University of Victoria
Title: Mapping the Metallicity Gradient in the Dwarf Galaxy WLM
Abstract: In this proposal we request Washington photometry to study the spatial distribution of metal-poor stars in the distant, isolated dwarf galaxy, WLM. In our pilot spectroscopic survey we found tantalizing evidence for an old metal poor halo. R,I and Washington C photometry has been successful in providing metallicities down to [Fe/H]~ -2 in extra-galactic populations. The photometric metallicity distribution we observe here will allow us to explore the spatial distribution of the most metal-poor stars, providing unambiguous confirmation of a stellar halo and metallicity gradient. These data results will be used to test whether/how hierarchical merging scales to lower mass systems. With Washington photometry over the wide field of view of MOSAICII, we will be able to verify the existence of a spatially extended, metal-poor, spheroidal stellar halo, characterize its metallicity with respect to the population in the main body of the galaxy, and search for radial gradients that could be used to test low mass stellar halo formation models.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360