Structure and Evolution of Starburst and Normal Galaxies

We study the rest-frame morphology and structural properties of opticallyselected starburst galaxies at redshift z < 1, using multi-waveband (BViz) highresolution images taken by the Advanced Camera for Surveys (ACS) as part of theGreat Observatories Origins Deep Survey (GOODS). We classify galaxies intostarburst, early and late types by comparing their observed spectral energydistributions (SEDs) with local templates. We find that early-type systems havesignificantly higher rest-frame B -band concentration indices and AGN fraction(> 25%) than late-type spirals and optically-selected starbursts. These resultsare consistent with the scenario in which early-epoch (z > 1) gas-richdissipative processes (e.g., major mergers) have played an important role indeveloping large central concentrations in early-type E/Sa galaxies, leading toconcurrent growth of central black holes and bulge formation in some of theseearly merger events. The starbursts have, on average, larger asymmetries thanour control sample of normal galaxies, suggesting that a significant fractionof the starburst activity is tidally triggered.Comment: Accepted for publication in ApJ