The merging cluster Abell 1758 revisited: multi-wavelength observations
  and numerical simulations
  [Abriged] We discuss here the properties of the double cluster Abell 1758, at
a redshift z~0.279, which shows strong evidence for merging. We analyse the
optical properties of the North and South clusters of Abell 1758 based on deep
imaging obtained with the CFHT archive Megaprime/Megacam camera in the g' and
r' bands, covering a total region of about 1.05 x 1.16 deg^2. Our X-ray
analysis is based on archive XMM-Newton images. Numerical simulations were
performed using an N-body algorithm to treat the dark matter component, a
semi-analytical galaxy formation model for the evolution of the galaxies and a
grid-based hydrodynamic code with a PPM scheme for the dynamics of the
intra-cluster medium. We have computed galaxy luminosity functions (GLFs) and
2D temperature and metallicity maps of the X-ray gas, which we then compared to
the results of our numerical simulations. The GLFs of Abell 1758 North are well
fit by Schechter functions in the g' and r' bands, but a small excess of bright
galaxies, particularly in the r' band. On the contrary, the GLFs of Abell 1758
South are not well fit by Schechter functions: excesses of bright galaxies are
seen in both bands. Comparing observational results to those derived from
numerical simulations, we could mimic the most prominent features present in
the metallicity map and propose an explanation for the dynamical history of the
cluster. Particilarly, we found in particular that in the metal rich elongated
regions of the North cluster, winds had been more efficient in transporting
metal enriched gas to the outskirts than ram pressure stripping. We confirm the
merging structure of each of the North and South clusters, both at optical and
X-ray wavelengths.
