[VCA2002] 2 , the SIMBAD biblio

We report on low-resolution multi-object spectroscopy of 65 objects from I(AB)≃20 to I(AB)≃25 in the HDF-S obtained with the VLT Focal Reducer/low dispersion Spectrograph (FORS2). 18 objects belong to the HDF-S proper, i.e. the WFPC2 deep area. 15 high-redshift galaxies with 2.0<z<3.5 (10 in the HDF-S proper) have been identified. The spectroscopic redshifts are in good agreement with the photometric ones derived from a χ² minimization technique comparing the observed spectral energy distribution with synthetic libraries and with a new neural network (NN) approach. The dispersion with the former method is σ_z=0.16 whereas the latter provides σ_z=0.13. No ``catastrophic'' difference is encountered. The inferred star formation rates of the individual objects range from tens to a few hundreds of M_☉/yr and the global star formation rate of the Universe at <z≥∼2.4 is estimated to be 0.15M_☉/yr/Mpc³ with a statistical error of 0.04. Evidence for large-scale structure is found with two groups' redshifts observed at z≃2.1 and z≃2.7 and a pronounced low redshift peak around z≃0.58. An elliptical galaxy lensing a background object turns out to be at a redshift z=0.577.