Abundance profiles and cool cores in galaxy groups
  Using data from the Two Dimensional XMM-Newton Group Survey (2dXGS), we have
examined the abundance profile properties of both cool core (CC) and non cool
core (NCC) galaxy groups. The ten NCC systems in our sample represent a
population which to date has been poorly studied in the group regime. Fitting
the abundance profiles as a linear function of log radius, we find steep
abundance gradients in cool core (CC) systems, with a slope of -0.54+/-0.07. In
contrast, non cool core (NCC) groups have profiles consistent with uniform
metallicity. Many CC groups show a central abundance dip or plateau, and we
find evidence for anticorrelation between the core abundance gradient and the
1.4 GHz radio power of the brightest group galaxy (BGG) in CC systems. This may
indicate the effect of AGN-driven mixing within the central ~0.1r_500. It is
not possible to discern whether such behaviour is present in the NCC groups,
due to the small and diverse sample with the requisite radio data. The lack of
strong abundance gradients in NCC groups, coupled with their lack of cool core,
and evidence for enhanced substructure, leads us to favour merging as the
mechanism for disrupting cool cores, although we cannot rule out disruption by
a major AGN outburst. Given the implied timescales, the disruptive event must
have occurred within the past few Gyrs in most NCC groups.
