2014MNRAS.437..730O

We present temperature and abundance maps of the central 125kpc of the NGC 5044 galaxy group, based on a deep XMM-Newton observation. The abundance map reveals an asymmetrical abundance structure, with the centroid of the highest abundance gas offset ∼ 22kpc north-west of the galaxy centre, and moderate abundances extending almost twice as far to the south-east than in any other direction. The abundance distribution is closely correlated with two previously identified cold fronts and an arc-shaped region of surface brightness excess, and it appears that sloshing, induced by a previous tidal encounter, has produced both the abundance and surface brightness features. Sloshing dominates the uplift of heavy elements from the group core on large scales, and we estimate that the south-east extension (the tail of the sloshing spiral) contains at least 1.2x10⁵M_☉ more iron than would be expected of gas at its radius. Placing limits on the age of the encounter we find that if, as previously suggested, the disturbed spiral galaxy NGC 5054 was the perturber, it must have been moving supersonically when it transited the group core. We also examine the spectral properties of emission from the old, detached radio lobe south-east of NGC 5044, and find that they are consistent with a purely thermal origin, ruling out this structure as a significant source of spectrally hard inverse-Compton emission.