case western reserve university



Modeling the Stellar Populations in the Sagittarius Dwarf Galaxy

Andy Layden (Bowling Green)

The Sagittarius Dwarf Galaxy, discovered in 1994, is a small, gas-poor galaxy located on the opposite side of the Galactic bulge from the Sun. As the nearest galaxy to our Milky Way, it presents an unprecedented opportunity to study the stellar populations and the history of star formation in a dwarf galaxy. I will present photometric observations of Sagittarius, along with a preliminary description of the ages and metallicities of its stellar components using simple isochrones. I will then describe results of a more sophisticated technique which matches synthetic color magnitude diagrams to the observed diagram. I will then compare the star formation history of Sagittarius with that of other dwarf galaxies, in an attempt to draw more general conclusions about the histories of these intriguing galaxies.