Tuesday

We use an inhomogeneous chemical evolution (ICE) code to model local dwarf galaxies, such as Draco. Using ICE as opposed to traditional chemical evolution models allows a natural dispersion to occur within the output data, thus mimicking observations. As this dispersion is highest at low metallicities, ICE can be used as a powerful probe of the early universe. One major advantage of the method described is that the dispersion is provided without the computational time required by fully hydrodynamic codes.

We find that to reproduce the observed europium abundances of Draco, we require magneto-rotationally driven supernova as the dominant source of europium. Other sites, such as neutron star mergers are not required, even considering unrealistically short coalescence timescales their contribution is minimal. This analysis of Draco is performed using the NuGrid stellar yields.

Furthermore, for the first time we use the ICE code to model the star formation history, gas fraction, and abundance of alpha elements in local dwarf galaxies. This is achieved through careful tuning of parameters such as inflow and outflow rates according to the different sets of stellar yields used, including those of NuGrid and Woosley & Weaver.