Abell 2142 at large scales: An extreme case for sloshing?^⋆

¹ Università degli Studi di Milano, Dip. di Fisica, via Celoria 16, 20133 Milano, Italy
e-mail: mariachiara.rossetti@unimi.it
² IASF – Milano INAF, via Bassini 15, 20133 Milano, Italy
³ Department of Astronomy, University of Geneva, ch. d’Ecogia 16, 1290 Versoix, Switzerland
⁴ INAF, Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate (LC), Italy
⁵ Department of Physics and Astronomy, University of California at Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697-4572, USA
⁶ Hamburger Sternwarte, Universitaet Hamburg, Gojensbergsweg 112, 21029 Hamburg, Germany

Received: 19 February 2013
Accepted: 9 May 2013

Abstract

We present results obtained with a new XMM-Newton observation of A2142, a textbook example of a cluster with multiple cold fronts, which has been studied in detail with Chandra but whose large scale properties are presented here for the first time. We report the discovery of a new cold front, the most distant one ever detected in a galaxy cluster, at about 1 Mpc from the center to the SE. Residual images, thermodynamics, and metal abundance maps qualitatively agree with predictions from numerical simulations of the sloshing phenomenon. However, the scales involved are much larger, similar to what has been recently observed in the Perseus cluster. These results show that sloshing is a cluster-wide phenomenon and is not confined in the cores. Sloshing extends well beyond the cooling region, involving a high fraction of the ICM up to almost half of the virial radius. The absence of a cool core and a newly discovered giant radio halo in A2142, in spite of its relaxed X-ray morphology, suggest that large scale sloshing, or the intermediate merger that caused it, may trigger Mpc-scale radio emission and may lead to the disruption of the cluster cool core.