Abstract

We describe the construction of a catalogue of galaxies in the optical field of the Hubble Deep Field South. The HDF-S observations produced WFPC2 images in U, B,
V, and I, the version 1 data have been made public on 23 November 1999. The effective field of view is 4.38 arcmin2, and the 5sigma limiting magnitudes (in a FWHM
aperture) are 28.87, 29.71, 30.19, 29.58 in the U, B, V and I bands, respectively. We created a catalogue for each pass-band (I814, V606, B450, U300), using simulations to
account for incompleteness and spurious sources contamination. Along with photometry in all bands, we determined on the I814-selected catalogue (I814<26) structural
parameters, such as a metric apparent size, derived from the petrosian radius, an asymmetry index, light concentration indexes and the mean surface brightness within
the petrosian radius.
The full catalogue is also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

Interpreting the optical data of the Hubble Deep Field South: colors, morphological number counts and photometric redshifts
Volonteri, M.; Saracco, P.; Chincarini, G.; Bolzonella, M., 2000, A&A 362, 487

Abstract
We present an analysis of the optical data of the Hubble Deep Field South. We derive F300WAB, F450WAB, F606WAB and F814WAB number counts for galaxies in our
catalogue (Volonteri et al. 2000): the number-counts relation has an increasing slope up to the limits of the survey in all four bands. The slope is steeper at shortest
wavelengths: we estimated gamma F300W_AB ~ 0.47+/-0.05, gamma F450W_AB ~ 0.35+/-0.02, gamma F606W_AB ~ 0.28+/-0.01 and gamma F814W_AB ~ 0.28+/-0.01. The
color-magnitude relations of galaxies shows an initial blueing trend, which gets flat in the faintest magnitude bin and the sample contains a high fraction of galaxies bluer
than local sources, with about 50% of sources with F814WAB>27 having (F450W-F606W)AB bluer than a typical local irregular galaxy. Morphological number counts are
actually dominated by late type galaxies, while early type galaxies show a decreasing slope at faint magnitudes. Combining this information with photometric redshifts,
we notice that galaxies contributing with a steep slope to the number counts have zgtrsim1 , suggesting a moderate merging. However we emphasize that any cut in
apparent magnitude at optical wavelengths results in samples biased against elliptical galaxies, affecting as a consequence the redshift distributions and the implications
on the evolution of galaxies along the Hubble sequence.