SuperModel predictions in the outskirts of the galaxy cluster Zwicky 3146

Abstract

ABSTRACT The relaxed galaxy cluster Zwicky 3146 is analysed via the SuperModel, a tool already tested on many clusters since 2009. In particular, this analysis is focused on the intracluster medium X-ray temperature data measured by XMM–Newton up to r500. A previous analysis was based on the temperature profile derived from the Sunyaev-Zeld′ovich effect pressure data. The gas mass fraction fgas is obtained from the resulting SuperModel temperature profile extrapolated up to the virial radius R, which turns out in agreement with the steep temperature profiles observed by Suzaku, and from the gas density profile observed by XMM–Newton. The comparison between fgas with the universal value indicates a non-thermal pressure component, pnth, in the cluster outskirts. The SuperModel analysis shows a ratio α(R) (${\simeq}50{{\ \rm per\ cent}}$) of pnth to the total pressure greater than the values found by simulations, highlighting the possible presence of accreting substructures and inhomogeneities in the gas density profile. Once that this profile is corrected for clumpiness, the level of pnth is considerably reduced. However, a significant turbulence ($\alpha (R)\simeq 20{{\ \rm per\ cent}}$) and entropy flattening are still present in the outskirts of the galaxy cluster Zwicky 3146.