The Great Observatories Origins Deep Survey VLT/FORS2 spectroscopy in the GOODS-South Field

摘要

We present the first results of the ESO/ GOODS program of spectroscopy of faint galaxies in the Chandra Deep Field South ( CDF- S). 399 spectra of 303 unique targets have been obtained in service mode with the FORS2 spectrograph at the ESO/ VLT, providing 234 redshift determinations ( the median of the redshift distribution is at 1.04). The typical redshift uncertainty is estimated to be sigma(z) similar or equal to 0.001. Galaxies have been color selected in a way that the resulting redshift distribution typically spans from z = 0.5 to 2. The reduced spectra and the derived redshifts are released to the community through the ESO web page http:// www. eso. org/ science/ goods/. Large scale structure is clearly detected at z similar or equal to 0.67, 0.73, 1.10 and 1.61. Three Lyman- break galaxies have also been included as targets and are confirmed to have redshifts z = 4.800, 4.882 and 5.828. In a few cases, we observe clear [ OII] 3727 rotation curves, even at the relatively low resolution ( R = 860) of the present observations. Assuming that the observed velocity structure is due to dynamically- relaxed rotation, this is an indication of large galactic masses ( few times 10(11) M.) at z similar to 1.