Gentle reenergization of electrons in merging galaxy clusters
MetadataShow full item record
Galaxy clusters are the most massive constituents of the large-scale structure of the universe. Although the hot thermal gas that pervades galaxy clusters is relatively well understood through observations with x-ray satellites, our understanding of the nonthermal part of the intracluster medium (ICM) remains incomplete. With Low-Frequency Array (LOFAR) and Giant Metrewave Radio Telescope (GMRT) observations, we have identified a phenomenon that can be unveiled only at extremely low radio frequencies and offers new insights into the nonthermal component. We propose that the interplay between radio-emitting plasma and the perturbed intracluster medium can gently reenergize relativistic particles initially injected by active galactic nuclei. Sources powered through this mechanism can maintain electrons at higher energies than radiative aging would allow. If this mechanism is common for aged plasma, a population of mildly relativistic electrons can be accumulated inside galaxy clusters providing the seed population for merger-induced reacceleration mechanisms on larger scales such as turbulence and shock waves.
Showing items related by title, author, creator and subject.
Hatch, N.; De Breuck, C.; Galametz, A.; Miley, G.; Overzier, R.; Röttgering, H.; Doherty, M.; Kodama, T.; Kurk, J.; Seymour, Nick; Venemans, B.; Vernet, J.; Zirm, A. (2011)We study the environments of six radio galaxies at 2.2 < z < 2.6 using wide-field near-infrared images. We use colour cuts to identify galaxies in this redshift range, and find that three of the radio galaxies are surrounded ...
The XXL Survey: XXXIV. Double Irony in XXL-North: A tale of two radio galaxies in a supercluster at z = 0.14Horellou, C.; Intema, Hubertus; Smolcic, V.; Nilsson, A.; Karlsson, F.; Krook, C.; Tolliner, L.; Adami, C.; Benoist, C.; Birkinshaw, M.; Caretta, C.; Chiappetti, L.; Delhaize, J.; Ferrari, C.; Fotopoulou, S.; Guglielmo, V.; Kolokythas, K.; Pacaud, F.; Pierre, M.; Poggianti, B.; Ramos-Ceja, M.; Raychaudhury, S.; Röttgering, H.; Vignali, C. (2018)Aims. We show how the XXL multiwavelength survey can be used to shed light on radio galaxies and their environment. Methods. Two prominent radio galaxies were identified in a visual examination of the mosaic of XXL-North ...
De Gasperin, F.; Intema, Hubertus; Ridl, J.; Salvato, M.; Van Weeren, R.; Bonafede, A.; Greiner, J.; Cassano, R.; Brüggen, M. (2017)Context. Galaxy clusters undergo mergers that can generate extended radio sources called radio relics. Radio relics are the consequence of merger-induced shocks that propagate in the intra cluster medium (ICM). Aims. In ...