1 Introduction

The Hubble Deep Field South (HDF-S) was observed in October 1998 by the Hubble Space Telescope (HST). It is the southern counterpart of the Hubble Deep Field North (HDF-N) and shares its characteristics of depth and spatial resolution. The HDF-S is a four arcmin²survey located at RA 22h 32m 56s, DEC -60$^\circ$ 33' 02'', observed during 150 orbits with the Wide Field Planetary Camera 2 (WFPC2). The WFPC2 detector is composed by 4 chips: the Planetary Camera (PC) with higher resolution (0.05 arcsec/pixel) and smaller field of view (35 $\times$ 35 arcsec²) and 3 Wide Field Cameras (WF), with a spatial resolution of 0.10 arcsec/pixel and a field of view of 77 $\times$ 77 arcsec². We will refer to the area of sky observed by the Planetary Camera as PC field, and to the one observed by the three Wide Field Cameras as WF field.

HDF-S images cover a wavelength range from the ultraviolet to near-infrared (4 broad-band filters roughly corresponding to standard UBVI). Images were taken in four filters: F300W, F450W, F606W, and F814W, by a dithering technique. Released images are a combination of all individual exposures, weighted for the background signal, and resampled to a pixel scale of 0.0398 arcsec/pixel using the "Drizzle'' package (Fruchter et al. 1997). Details about observations and data reduction may be found in the Hubble Deep Field South web page (http://www.stsci.edu/ftp/science/hdfsouth/hdfs.html).

The main goal of the two HDF campaigns is to study the characteristics of faint galaxies and provide constraints on models explaining the formation and evolution of galaxies, in particular the excess of faint blue sources. It is therefore crucial to have a reliable catalogue, both for sources detection and photometry. In this paper we present a galaxy catalogue derived from the public version 1 images in fits format of the WFPC2 data, released on 23 November 1999, along with documentation about data reduction and absolute calibration in the different bands.

This catalogue gives for each galaxy, besides photometric information in all the optical bands, metric size, mean surface brightness, asymmetry index and light concentration indexes, all fundamental for different cosmological and evolutionary tests.

In Sect. 2 we describe the applied detection procedure and in Sect. 3 the technique used to compute magnitudes, while in Sect. 4 we deal with the selection criteria adopted to extract the sample. In Sect. 5 we summarize the estimation of the sample completeness, while we discuss the possible oversampling of sub-galactic structures, such as HII regions, in high resolution imaging in Sect. 6. Finally in Sects. 7 and 8 we describe the technique used to recover galaxy colours and structural parameters respectively.