\label{fig:MassiveIGWhist} Kippenhahn diagram of our stellar model, with the x-axis showing the time until core collapse. Light blue shaded regions are convective. Solid colored lines show helium, carbon, oxygen, silicon, and iron core masses. We have labeled convective core burning phases with the element being burned in each phase. Dashed vertical lines show the locations (from left) of our helium core burning, carbon shell burning, oxygen shell burning, and silicon shell burning models used in Figures \ref{fig:Massivestruc} and \ref{fig:MassiveIGWtime}. The mass coordinate of the base of the convective shell, from which IGW propagate downwards, is labeled by a circle on each dashed line.