Abstract:

I use 16,000 galaxy spectra from the Sloan Digital Sky Survey to probe the varying stellar populations of early type galaxies throughout the structural space described by the Fundamental Plane. Not only do early type galaxies span a 2-dimensional family in the Fundamental Plane, they also span a 2-dimensional family in star formation histories. In addition to known variations with galaxy mass, I present evidence that stellar populations in these galaxies are intimately linked with their central dark matter fraction, revealing a connection between star formation history and structural evolution of the galaxy. I discuss these results in the context of different models for galaxy evolution in a hierarchical universe.