"Clumpy Galaxies in the Early Universe"

Debra Elmegreen (Vassar College)

Hubble Space Telescope observations out to z~5 in the Hubble Ultra Deep Field and to z~1 in GEMS and GOODS fields reveal galaxies with unusual clumpy morphologies, in addition to spirals and ellipticals. These high redshift galaxies are mostly starburst systems, with young star-forming complexes 100 to 1000 times more massive than in today's galaxies. The clumpy galaxies may grow primarily through gas accretion, and evolve into today's spirals when the star-forming clumps migrate to the centers to build bulges or dissolve to build exponential disks. Images, photometry, and computer simulations will be presented to show the evolutionary sequence.