@article{0b67a62018af444f92514498acc4b9e0,
title = "Radio observations of the merging galaxy cluster system Abell 3391-Abell 3395",
abstract = "The pre-merging system of galaxy clusters Abell 3391-Abell 3395 located at a mean redshift of 0.053 has been observed at 1 GHz in an ASKAP/EMU Early Science observation as well as in X-rays with eROSITA. The projected separation of the X-ray peaks of the two clusters is 50′ or 3.1 Mpc. Here we present an inventory of interesting radio sources in this field around this cluster merger. While the eROSITA observations provide clear indications of a bridge of thermal gas between the clusters, neither ASKAP nor MWA observations show any diffuse radio emission coinciding with the X-ray bridge. We derive an upper limit on the radio emissivity in the bridge region of (J)1 GHz < 1.2 × 10-44 W Hz-1 m-3. A non-detection of diffuse radio emission in the X-ray bridge between these two clusters has implications for particle-Acceleration mechanisms in cosmological large-scale structure. We also report extended or otherwise noteworthy radio sources in the 30 deg2 field around Abell 3391-Abell 3395. We identified 20 Giant Radio Galaxies, plus 7 candidates, with linear projected sizes greater than 1 Mpc. The sky density of field radio galaxies with largest linear sizes of >0.7 Mpc is ≈1.7 deg-2, three times higher than previously reported. We find no evidence for a cosmological evolution of the population of Giant Radio Galaxies. Moreover, we find seven candidates for cluster radio relics and radio halos.",
keywords = "Galaxies: clusters: intracluster medium, Radio continuum: galaxies, X-rays: galaxies: clusters",
author = "M. Br{\"u}ggen and Reiprich, {T. H.} and E. Bulbul and Koribalski, {B. S.} and H. Andernach and L. Rudnick and Hoang, {D. N.} and Wilber, {A. G.} and Duchesne, {S. W.} and A. Veronica and F. Pacaud and Hopkins, {A. M.} and Norris, {R. P.} and M. Johnston-Hollitt and Brown, {M. J.I.} and A. Bonafede and G. Brunetti and Collier, {J. D.} and Sanders, {J. S.} and E. Vardoulaki and T. Venturi and Kapinska, {A. D.} and J. Marvil",
note = "Funding Information: cA knowledgement. This work is based on data from eROSITA, the primary instrument aboard SRG, a joint Russian-German science mission supported by the Russian Space Agency (Roskosmos), in the interests of the Russian Academy of Sciences represented by its Space Research Institute (IKI), and the Deutsches Zentrum f{\"u}r Luft-und Raumfahrt (DLR). The SRG spacecraft was built by Lavochkin Association (NPOL) and its subcontractors, and is operated by NPOL with support from the Max Planck Institute for Extraterrestrial Physics (MPE). The development and construction of the eROSITA X-ray instrument was led by MPE, with contributions from the Dr. Karl Remeis Observatory Bamberg & ECAP (FAU Erlangen-N{\"u}rnberg), the University of Hamburg Observatory, the Leibniz Institute for Astrophysics Potsdam (AIP), and the Institute for Astronomy and Astrophysics of the University of T{\"u}bin-gen, with the support of DLR and the Max Planck Society. The Argelander Institute for Astronomy of the University of Bonn and the Ludwig Maximilians Universit{\"a}t Munich also participated in the science preparation for eROSITA. The eROSITA data shown here were processed using the eSASS software system developed by the German eROSITA consortium. The Australian SKA Pathfinder is part of the Australia Telescope National Facility which is managed by CSIRO. Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. ASKAP uses the resources of the Pawsey Supercomputing Centre. Establishment of ASKAP, the Murchison Radio-astronomy Observatory and the Pawsey Supercomputing Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund. We acknowledge the Wajarri Yamatji people as the traditional owners of the Observatory site. The Australia Telescope Compact Array (Parkes radio telescope/Mopra radio telescope/Long Baseline Array) is part of the Australia Telescope National Facility which is funded by the Australian Government for operation as a National Facility managed by CSIRO. This paper includes archived data obtained through the Australia Telescope Online Archive (http://atoa.atnf.csiro.au). This work was supported by resources provided by the Pawsey Supercomputing Centre with funding from the Australian Government and the Government of Western Australia. We acknowledge and thank the builders of ASKAPsoft. Support for the operation of the MWA is provided by the Australian Government (NCRIS), under a contract to Curtin University administered by Astronomy Australia Limited. M.B. acknowledges support from the Deutsche Forschungsgemeinschaft under Germany{\textquoteright}s Excellence Strategy – EXC 2121 “Quantum Universe” – 390833306. H.A. benefited from grant CIIC 90/2020 of Universidad de Guanajuato, Mexico. A.B. and D.N.H. acknowledge support from the ERC StG DRANOEL 714245. A.B. acknowledges support from the MIUR grant FARE “SMS”. S.W.D. acknowledges an Australian Government Research Training Program scholarship administered through Curtin University. L.R. receives support from the U.S. National Science Foundation grant AST17-14205 to the University of Minnesota. The authors made use of the database CATS (Verkhodanov et al. 2005) of the Special Astrophysical Observatory. Publisher Copyright: {\textcopyright} ESO 2021.",
year = "2021",
month = mar,
day = "1",
doi = "10.1051/0004-6361/202039533",
language = "English",
volume = "647",
journal = "Astronomy & Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",
}