Abstract:

The current standard cosmological scenario predicts that rich clusters of galaxies are still accreting mass. This dynamical activity is reflected on the intracluster plasma surface brightness, which often shows substructures. A remarkable feature observed in cool-core clusters is the presence of a spiral arm (eg., Laganá et al. 2010). The origin of this arm is probably the sloshing of the cool central gas by the off-axis collision of a passing group or cluster (Ascasibar \amp Markevitch 2006).The rich cluster Abell 2052 was extensively studied in X-ray by Blanton et al. (2011). They show the presence of a spiral structure extending more than 250 kpc, which is comprised of cool gas. Using hydrodynamical N-body simulations of cluster collision, we have recovered the dynamical history of Abell 2052 and reproduced the broad morphology of the spiral feature, as compared with newly computed hardness ratio map and X-ray imaging.We obtain two regimes that reproduce the desired features: (I) a close encounter and a recent event (0.8 Gyr since pericentric passage), and (II) a scenario with a larger impact parameter and older event (almost 2.6 Gyr since pericentric passage). Interestingly, in the second case, we were able to identify an observed optical counterpart - based on the light distribution obtained from the SDSS - at the same redshift of the perturbing galaxy group, with M$_500$ = (1.16\plusmn0.43)x10$^13$ M$_sun$ at about 2 Mpc from the centre of the major cluster.