The Nature of Near-UV Selected Objects in the Chandra Deep Field South

Duilia. F. de Mello, Jonathan. P. Gardner, T. Dahlen, C. J. Conselice, N. A. Grogin, A. M. Koekemoer

Published 2003-08-28Version 1

We present the first results of the pure parallel near-UV observations with WFPC2 in the Chandra Deep Field South. The main goal is to search for the population of objects that contribute to the rise in the volume-averaged star formation rate at intermediate redshifts (z<1). A total of 34 objects, were identified in the WFPC2 images and their counterparts found in the ACS GOODS images. We use template fitting of the spectral energy distributions to classify the objects and found that 17 are starbursts, 9 are late-type, 2 are early-type galaxies, and 6 are stars; two of the late-types and one of the starbursts are X-ray sources. The colors of the starbursts were reproduced by the stellar evolutionary synthesis code Starburst99 which shows a mixed population of bursts with ages < 1 Gyr. Analysis of the light concentration, asymmetry and clumpiness, shows that this sample is a mixed bag, containing dwarf ellipticals, early and late-spirals and peculiar objects which resemble mergers in progress.