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302 Grazian et al: Galaxies in GOODS-South
and facilities (Cowie et al. 2004; Mignoli et al.
2005; Vanzella et al. 2005).
A high-quality Multi-wavelength catalog
(MWC) has been produced using this public
dataset at the Astronomical Observatory of
Rome (AOR), on the basis of our previous experience
developed within K20 and HDFS surveys.
The scientific motivations are manifold:
first of all, the wide spatial and spectral coverage
of the GOODS field ensures an ideal
dataset to study the formation and evolution
of galaxies through the analysis of Luminosity,
Mass functions and clustering properties till
the highest available redshifts (z ∼ 7). With
the Spitzer data in the MIR, indeed, it is possible
to investigate the rest frame K-band till
z ∼ 3, which allows to derive precisely the
stellar mass in galaxies. The GOODS survey
is fundamental to understand the role of stars
and AGN in the energetic output of galaxies.
The large volume sampled is useful to lower
down biases due to cosmic variance, but still
not sufficient to eliminate them totally.
Not least, the GOODS data represent an
innovative challenge for detailed data analysis,
due to the large amount and complexity
of the imaging dataset. We have dedicated a
combined effort for software developing and
scientific analysis applied to a public dataset,
with the aim to build an important expertise
in the field of multi wavelength imaging surveys.
GOODS is the prototype of future wide
and deep surveys: it is an ideal dataset to test
smart software tools dealing with data coming
from different telescopes and of very dishomogeneous
quality.
2. The Data
The GOODS southern pointing, located over
the Chandra Deep Field South and encompassing
the ACS Ultra Deep Field and the GMASS
ESO Large Program (Galaxy Mass Assembly
ultra-deep Spectroscopic Survey, PI Cimatti),
has been the target of extensive observations
with ESO telescopes, carried on in the spirit
of public surveys. To date, the major effort has
been devoted to deep imaging observations in
the J, H and Ks bands with the VLT-ISAAC
infrared imager. The final area covered by the
Fig. 1. The ACS GOODS-S field with the ISAAC
tiling made by ESO to cover in J and Ks the whole
field. The cyan square marks the position of the
ACS UDF. The red rectangle marks the position of
the K20 survey. The four white quadrants show the
actual coverage of VLT-VIMOS U band imaging;
large gaps are visible, since the observing program
is just started.
Ks images approaches 135 arcmin 2 to a 1σ
limiting depth of typically 25-26 mag/arcmin 2
(AB), making it an unique combination of
depth and size in the near–IR. We have included
in our analysis the b, v, i and z ACS
images, the Spitzer data provided by IRAC instrument
(3.6, 4.5, 5.8 and 8.0 µm) and publicly
available U–band data from the 2.2ESO
(U 35 and U 38 ) and VLT-VIMOS (U VIMOS ), as
shown in Fig. 1. The complexity of these data
is not trivial: the magnitude limits, the pixel
size and the resolution of the various images
are heterogeneous, going from 24 to 30 mag,
from 0.03 to 0.6 arcsec/px and from 0.1 to 2.0
arcsec, respectively. Indeed the ISAAC imaging
has a different seeing from tile to tile, a further
complication for the detailed photometric
analysis of these data.
Objects in the GOODS field have been detected
in the z-band with the SExtractor soft-