Volume 396, Number 3, December IV 2002
|Page(s)||847 - 855|
|Section||Cosmology (including clusters of galaxies)|
|Published online||05 December 2002|
A VLT/FORS2 spectroscopic survey in the HDF-S*
European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany
2 Dipartimento di Astronomia dell'Università di Padova, Vicolo dell'Osservatorio 2, 35122 Padova, Italy
3 INAF – Osservatorio Astronomico di Trieste, via G.B. Tiepolo 11, 40131 Trieste, Italy
4 Space Telescope European Coordinating Facility, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany
5 Institut d'Astrophysique de Paris, 98bis boulevard Arago, 75014 Paris, France
6 INAF – Osservatorio Astronomico di Roma, via dell'Osservatorio 2, Monteporzio, Italy
7 INAF – Osservatorio Astronomico di Brera, via E. Bianchi 46, Merate, Italy
Corresponding author: E. Vanzella, firstname.lastname@example.org
Accepted: 30 September 2002
We report on low-resolution multi-object spectroscopy of 65 objects from to 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 (10 in the HDF-S proper) have been identified. The spectroscopic redshifts are in good agreement with the photometric ones derived from a 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 whereas the latter provides . No “catastrophic” difference is encountered. The inferred star formation rates of the individual objects range from tens to a few hundreds of yr-1 and the global star formation rate of the Universe at is estimated to be 0.15 yr-1 Mpc-3 with a statistical error of 0.04. Evidence for large-scale structure is found with two groups' redshifts observed at and and a pronounced low redshift peak around . An elliptical galaxy lensing a background object turns out to be at a redshift .
Key words: techniques: spectroscopic / galaxies: evolution / galaxies: formation / galaxies: distances and redshifts
© ESO, 2002
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.