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arXiv · 1906.07584

A radio ridge connecting two galaxy clusters in a filament of the cosmic web

F. Govoni·E. Orrù·A. Bonafede·M. Iacobelli·R. Paladino·F. Vazza·M. Murgia·V. Vacca·G. Giovannini·L. Feretti·F. Loi·G. Bernardi·C. Ferrari·R. F. Pizzo·C. Gheller·S. Manti·M. Brüggen·G. Brunetti·R. Cassano·F. de Gasperin·T. A. Enßlin·M. Hoeft·C. Horellou·H. Junklewitz·H. J. A. Röttgering·A. M. M. Scaife·T. W. Shimwell·R. J. van Weeren·M. Wise
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Abstract

Galaxy clusters are the most massive gravitationally bound structures in the Universe. They grow by accreting smaller structures in a merging process that produces shocks and turbulence in the intra-cluster gas. We observed a ridge of radio emission connecting the merging galaxy clusters Abell 0399 and Abell 0401 with the Low Frequency Array (LOFAR) at 140 MHz. This emission requires a population of relativistic electrons and a magnetic field located in a filament between the two galaxy clusters. We performed simulations to show that a volume-filling distribution of weak shocks may re-accelerate a pre-existing population of relativistic particles, producing emission at radio wavelengths that illuminates the magnetic ridge.

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F. Govoni, E. Orrù, A. Bonafede, M. Iacobelli, R. Paladino, F. Vazza, M. Murgia, V. Vacca, G. Giovannini, L. Feretti, F. Loi, G. Bernardi, C. Ferrari, R. F. Pizzo, C. Gheller, S. Manti, M. Brüggen, G. Brunetti, R. Cassano, F. de Gasperin, T. A. Enßlin, M. Hoeft, C. Horellou, H. Junklewitz, H. J. A. Röttgering, A. M. M. Scaife, T. W. Shimwell, R. J. van Weeren, M. Wise. 2019-06-18. A radio ridge connecting two galaxy clusters in a filament of the cosmic web. https://doi.org/10.1126/science.aat7500

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