Large Infrared and Optical Color Gradients in the Cartwheel Ring Galaxy: Evidence for the First Epoch of Star Formation in the Wake of an Expanding Ring, P.M. Marcum, P.N. Appleton, James L. Higdon
James L. Higdon

A Spatially Resolved Sequence of Stellar Evolution Within the Cartwheel Ring Galaxy, P.M. Marcum, P. N. Appleton, James L. Higdon
James L. Higdon