Context. The Frontier Fields survey is a pioneering observational
program aimed at collecting photometric data, both from space (Hubble
Space Telescope and Spitzer Space Telescope) and from ground-based
facilities (VLT Hawk-I), for six deep fields pointing at clusters of
galaxies and six nearby deep parallel fields, in a wide range of
passbands. The analysis of these data is a natural outcome of the
Astrodeep project, an EU collaboration aimed at developing methods and
tools for extragalactic photometry and creating valuable public
photometric catalogues. Aims: We produce multiwavelength
photometric catalogues (from B to 4.5 μm) for the first two of the
Frontier Fields, Abell-2744 and MACS-J0416 (plus their parallel fields).
Methods: To detect faint sources even in the central regions of
the clusters, we develop a robust and repeatable procedure that uses the
public codes Galapagos and Galfit to model and remove most of the light
contribution from both the brightest cluster members, and the
intra-cluster light. We perform the detection on the processed HST H160
image to obtain a pure H-selected sample, which is the primary catalogue
that we publish. We also add a sample of sources which are undetected in
the H160 image but appear on a stacked infrared image. Photometry on the
other HST bands is obtained using SExtractor, again on processed images
after the procedure for foreground light removal. Photometry on the
Hawk-I and IRAC bands is obtained using our PSF-matching deconfusion
code t-phot. A similar procedure, but without the need for the
foreground light removal, is adopted for the Parallel fields.
Results: The procedure of foreground light subtraction allows for the
detection and the photometric measurements of ~2500 sources per field.
We deliver and release complete photometric H-detected catalogues, with
the addition of the complementary sample of infrared-detected sources.
All objects have multiwavelength coverage including B to H HST bands,
plus K-band from Hawk-I, and 3.6-4.5 μm from Spitzer. full and
detailed treatment of photometric errors is included. We perform basic
sanity checks on the reliability of our results. Conclusions: The
multiwavelength photometric catalogues are available publicly and are
ready to be used for scientific purposes. Our procedures allows for the
detection of outshone objects near the bright galaxies, which, coupled
with the magnification effect of the clusters, can reveal extremely
faint high redshift sources. Full analysis on photometric redshifts is
presented in Paper II.
The catalogues, together with the final processed images for all HST
bands (as well as some diagnostic data and images), are publicly
available and can be downloaded from the Astrodeep website at http://www.astrodeep.eu/frontier-fields/
and from a dedicated CDS webpage (http://astrodeep.u-strasbg.fr/ff/index.html).
The catalogues are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://126.96.36.199) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/590/A31
- methods: data analysis
- galaxies: photometry
- galaxies: high-redshift