The clusters Abell~222 and Abell~223: a multi-wavelength view
  (Abstract abridged) The Abell 222 and 223 clusters are located at an average
redshift z ~ 0.21 and are separated by 0.26 deg. Signatures of mergers have
been previously found in these clusters, both in X-rays and at
opticalwavelengths, thus motivating our study. In X-rays, they are relatively
bright, and Abell 223 shows a double structure. A filament has also been
detected between the clusters both at optical and X-ray wavelengths. We analyse
the optical properties of these two clusters based on deep imaging in two
bands, derive their galaxy minosity functions (GLFs) and correlate these
properties with X-ray characteristics derived from XMM-Newton data. The GLFs of
Abell 222 in the g' and r' bands are well fit by a Schechter function; the GLF
is steeper in r' than in g'. For Abell 223, the GLFs in both bands require a
second component at bright magnitudes, added to a Schechter function; they are
similar in both bands. The Serna & Gerbal method allows to separate well the
two clusters. No obvious filamentary structures are detected at very large
scales around the clusters, but a third cluster at the same redshift, Abell
209, is located at a projected distance of 19.2 Mpc. X-ray temperature and
metallicity maps reveal that the temperature and metallicity of the X-ray gas
are quite homogeneous in Abell 222, while they are very perturbed in Abell 223.
The Abell 222/Abell 223 system is complex. The two clusters that form this
structure present very different dynamical states. Signs of recent interactions
are also detected in the optical data where this cluster shows a ``perturbed''
GLF. In summary, the multiwavelength analyses of Abell 222 and Abell 223 are
used to investigate the connection between the ICM and the cluster galaxy
properties in an interacting system.
