2019/02/01 by G. Di Gennaro, R. J. van Weeren, F. Andrade-Santos +14 · 1 voice · 2 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Brightness #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Mach number #Physics #Radio galaxy #Shock (circulatory) #Shock wave #Spectral index #Spectral line #Surface brightness #astro-ph.HE
paper · pdf · doi:10.3847/1538-4357/ab03cd
21 pages, 15 figures, 4 tables; accepted for publication in ApJ
arxiv created 2019/02/01 · arxiv published 2019/02/01 · openalex created_date 2019/02/21 · openalex publication_date 2019/03/01 · arxiv updated 2019/03/13 · openalex updated_date 2026/08/05
Abstract We 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 from the density jump. We also measure and 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 ( ). 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 . The low surface brightness and reduced integration time for this region might have prevented the detection. The Chandra surface brightness profile suggests , while the Suzaku temperature measurements found . Finally, we also detect a merger-induced cold front on the western side of the cluster, behind the shock that traces the western relic.