Formation of Dwarf Galaxies and Globular Clusters in the Tidal Debris of Galaxy Interactions

Star formation proceeds in many environments, from gradual self-regulating spiral disks, to the vicinity of interacting galaxies. In the course of an interaction, global starbursts can be triggered, star clusters are formed (some are perhaps the progenitors of globulars), and star-forming clumps of various sizes are formed in the tidal debris. It is common for a large clump, consistent with a dwarf galaxy, to be found at the end of the optical tail. In this talk, I will explore the hypothesis that this tidal dwarf galaxy formation is not just a "fluke", but is rather an important contributor to the dwarf galaxy population. Also, the range of sizes of structures to form in tidal debris will be discussed. New Hubble Space Telescope WFPC2 images of Hickson compact group 92 (Stephan's quintet) will be presented. A study of the colors of the point sources in this complex field shows several phases of star formation, and allows us to reconstruct the history of interactions.