Stellar halo constraints on simulated late-type galaxies

How do late-type spiral galaxies form within the context of a cold dark matter cosmology? We contrast N-body, smoothed particle hydrodynamical simulations of galaxy formation that employ two different supernova feedback mechanisms. Observed mass and metallicity distributions of the stellar haloes of the Milky Way and M31 provide constraints on these models. A strong feedback model, incorporating an adiabatic phase in starburst regions, better reproduces these observational properties than our comparative thermal feedback model. This demonstrates the importance of energy feedback in regulating star formation in small systems, which collapse at early epochs, in the evolution of late-type disc galaxies.