Savini, F.F.SaviniBonafede, A.A.BonafedeBrüggen, M.M.Brüggenvan Weeren, R.R.van WeerenBrunetti, G.G.BrunettiIntema, H.H.IntemaBOTTEON, AndreaAndreaBOTTEONShimwell, T.T.ShimwellWilber, A.A.WilberRafferty, D.D.RaffertyGiacintucci, S.S.GiacintucciCASSANO, RossellaRossellaCASSANOCuciti, V.V.CucitiDE GASPERIN, FrancescoFrancescoDE GASPERINRöttgering, H.H.RöttgeringHoeft, M.M.HoeftWhite, G.G.White2021-02-152021-02-1520180035-8711http://hdl.handle.net/20.500.12386/30391Diffuse synchrotron radio emission from cosmic ray electrons is observed at the centre of a number of galaxy clusters. These sources can be classified either as giant radio haloes, which occur in merging clusters, or as mini haloes, which are found only in cool-core clusters. In this paper, we present the first discovery of a cool-core cluster with an associated mini halo that also shows ultra-steep-spectrum emission extending well beyond the core that resembles radio halo emission. The large-scale component is discovered thanks to LOFAR observations at 144 MHz. We also analyse GMRT observations at 610 MHz to characterize the spectrum of the radio emission. An X-ray analysis reveals that the cluster is slightly disturbed, and we suggest that the steep-spectrum radio emission outside the core could be produced by a minor merger that powers electron re-acceleration without disrupting the cool core. This discovery suggests that, under particular circumstances, both a mini halo and giant halo could co-exist in a single cluster, opening new perspectives for particle acceleration mechanisms in galaxy clusters.STAMPAenArticle10.1093/mnras/sty11252-s2.0-85052508673000439547400062https://academic.oup.com/mnras/article-abstract/478/2/2234/4990955?redirectedFrom=fulltext2018MNRAS.478.2234SFIS/05 - ASTRONOMIA E ASTROFISICA