The research to be supported by this award will focus on the origin of spiral structure in galaxies. Images of approximately 100 galaxies will be examined in order to determine the location of enhanced star formation ridges and other features which will be useful for understanding the dynamics and structure of spiral galaxies. This information will also be used to address questions about how strong spiral density waves trigger star formation in the disk of a galaxy, the properties of spiral structure in galaxies, and how environment affects spiral structure. The Principal Investigators are recognized experts in this research area.