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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - The case for electron re-acceleration at galaxy cluster shocks
AU - van Weeren, Reinout
AU - Santos, Felipe
AU - Dawson, William
AU - Golovich, Nathan
AU - Brüggen, Marcus
AU - Wittman, David
AU - Jee, M. James
AU - Sobral, David
AU - Stroe, Andra
N1 - © 2017 Macmillan Publishers Limited. All Rights Reserved.
PY - 2017/1/4
Y1 - 2017/1/4
N2 - On the largest scales, the Universe consists of voids and filaments making up the cosmic web. Galaxy clusters are located at the knots in this web, at the intersection of filaments. Clusters grow through accretion from these large-scale filaments and by mergers with other clusters and groups. In a growing number of galaxy clusters, elongated Mpc-size radio sources have been found [1, 2]. Also known as radio relics, these regions of diffuse radio emission are thought to trace relativistic electrons in the intracluster plasma accelerated by low-Mach number shocks generated by cluster-cluster merger events [3]. A long-standing problem is how low-Mach number shocks can accelerate electrons so efficiently to explain the observed radio relics. Here we report the discovery of a direct connection between a radio relic and a radio galaxy in the merging galaxy cluster Abell 3411-3412 by combining radio, X-ray, and optical observations. This discovery indicates that fossil relativistic electrons from active galactic nuclei are re-accelerated at cluster shocks. It also implies that radio galaxies play an important role in governing the non-thermal component of the intracluster medium in merging clusters.
AB - On the largest scales, the Universe consists of voids and filaments making up the cosmic web. Galaxy clusters are located at the knots in this web, at the intersection of filaments. Clusters grow through accretion from these large-scale filaments and by mergers with other clusters and groups. In a growing number of galaxy clusters, elongated Mpc-size radio sources have been found [1, 2]. Also known as radio relics, these regions of diffuse radio emission are thought to trace relativistic electrons in the intracluster plasma accelerated by low-Mach number shocks generated by cluster-cluster merger events [3]. A long-standing problem is how low-Mach number shocks can accelerate electrons so efficiently to explain the observed radio relics. Here we report the discovery of a direct connection between a radio relic and a radio galaxy in the merging galaxy cluster Abell 3411-3412 by combining radio, X-ray, and optical observations. This discovery indicates that fossil relativistic electrons from active galactic nuclei are re-accelerated at cluster shocks. It also implies that radio galaxies play an important role in governing the non-thermal component of the intracluster medium in merging clusters.
U2 - 10.1038/s41550-016-0005
DO - 10.1038/s41550-016-0005
M3 - Journal article
VL - 1
JO - Nature Astronomy
JF - Nature Astronomy
SN - 2397-3366
IS - 1
M1 - 0005
ER -