Di Gennaro, G.G.Di Gennarovan Weeren, R. J.R. J.van WeerenAndrade-Santos, F.F.Andrade-SantosAkamatsu, H.H.AkamatsuRandall, S. W.S. W.RandallForman, W.W.FormanKraft, R. P.R. P.KraftBRUNETTI, GIANFRANCOGIANFRANCOBRUNETTIDawson, W. A.W. A.DawsonGolovich, N.N.GolovichJones, C.C.Jones2021-02-182021-02-1820190004-637Xhttp://hdl.handle.net/20.500.12386/30467We present the results from new deep Chandra (∼410 ks) and Suzaku (∼180 ks) observations of the merging galaxy cluster ZwCl 0008.8+5215 (z = 0.104). Previous radio observations revealed the presence of a double radio relic located diametrically west and east of the cluster center. Using our new Chandra data, we find evidence for the presence of a shock at the location of the western relic, RW, with a Mach number {{ \mathcal M }}{SX}={1.48}-0.32+0.50 from the density jump. We also measure {{ \mathcal M }}{TX}={2.35}-0.55+0.74 and {{ \mathcal M }}{TX}={2.02}-0.47+0.74 from the temperature jump, with Chandra and Suzaku, respectively. These values are consistent with the Mach number estimate from a previous study of the radio spectral index, under the assumption of diffusive shock acceleration ({{ \mathcal M }}RW}={2.4}-0.2+0.4). Interestingly, the western radio relic does not entirely trace the X-ray shock. A possible explanation is that the relic traces fossil plasma from nearby radio galaxies that is reaccelerated at the shock. For the eastern relic we do not detect an X-ray surface brightness discontinuity, despite the fact that radio observations suggest a shock with {{ \mathcal M }}RE}={2.2}-0.1+0.2. The low surface brightness and reduced integration time for this region might have prevented the detection. The Chandra surface brightness profile suggests { \mathcal M }≲ 1.5, while the Suzaku temperature measurements found {{ \mathcal M }}{TX}={1.54}-0.47+0.65. Finally, we also detect a merger-induced cold front on the western side of the cluster, behind the shock that traces the western relic.STAMPAenArticle10.3847/1538-4357/ab03cd2-s2.0-85063592428000460449000011https://iopscience.iop.org/article/10.3847/1538-4357/ab03cd2019ApJ...873...64DFIS/05 - ASTRONOMIA E ASTROFISICA