We present deep Chandra , XMM-Newton , Giant Metrewave Radio Telescope and H \alpha observations of the group-group merger NGC 6338 .
X-ray imaging and spectral mapping show that as well as trailing tails of cool , enriched gas , the two cool cores are embedded in an extensive region of shock heated gas with temperatures rising to \sim 5 keV .
The velocity distribution of the member galaxies show that the merger is occurring primarily along the line of sight , and we estimate that the collision has produced shocks of Mach number \mathcal { M } =2.3 or greater , making this one of the most violent mergers yet observed between galaxy groups .
Both cool cores host potential AGN cavities and H \alpha nebulae , indicating rapid radiative cooling .
In the southern cool core around NGC 6338 , we find that the X-ray filaments associated with the H \alpha nebula have low entropies ( < 10 \mbox { ~ { } keV } \mbox { ~ { } cm } ^ { 2 } ) and short cooling times ( \sim 200-300 Myr ) .
In the northern core we identify an H \alpha cloud associated with a bar of dense , cool X-ray gas offset from the dominant galaxy .
We find no evidence of current jet activity in either core .
We estimate the total mass of the system and find that the product of this group-group merger will likely be a galaxy cluster .