NGC 499 - Mapping the merger of two X-ray luminous galaxy groups

We propose a re-observation of NGC 499 which, with NGC 507, forms one of the best examples of a group-group merger in the local universe. Excellent archival XMM data for NGC 507 is available, but ~80% of our 55 ks AO5 observation of NGC 499 was lost to background flaring. With this re-observation we will be able to produce high resolution spectral maps of both groups and the gas between them, providing a wealth of data on the effects of the merger on the two systems. We will search for signs of tidal stripping and gas compression, and produce models of the temperature, abundance and mass distribution out to ~600 kpc, providing detailed information on the structure of the two systems and shedding light on this important stage in the evolution of groups.