Forming one of the most massive objects in the Universe: The quadruple
  merger in Abell 1758
  Abell1758 is a system of two galaxy clusters, a more massive, northern
cluster and a southern cluster. Both parts are undergoing major merger events
at different stages. Although the mass of the merger constituents provides
enough energy to produce visible shock fronts in the X-ray, none have been
found to date. We present detailed temperature and abundance maps based on
Chandra ACIS data, and identify several candidates for shocks and cold fronts
from a smoothed gradient map of the surface brightness. One candidate can be
confirmed as the missing shock front in the northern cluster through X-ray
spectroscopy. Non-thermal radio emission observed with the GMRT confirms the
presence of radio halos in the northern and southern clusters, and shows
evidence for a relic in the periphery of the southern cluster. We do not find
evidence for shocked gas between A1758N and A1758S.
