The XXL Survey: XXXIV. Double Irony in XXL-North: A tale of two radio galaxies in a supercluster at z = 0.14
Journal article, 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 obtained with the Giant Metrewave Radio Telescope at 610 MHz. Counterparts were searched for in other bands. Spectroscopic redshifts from the GAMA database were used to identify clusters and/or groups of galaxies, estimate their masses with the caustic method, and quantify anisotropies in the surrounding galaxy distribution via a Fourier analysis. Results. Both radio galaxies are of FR I type and are hosted by early-type galaxies at a redshift of 0.138. The first radio source, named the Exemplar, has a physical extent of ∼400 kpc; it is located in the cluster XLSSC 112, which has a temperature of ∼2 keV, a total mass of ∼1014 Mo, and resides in an XXL supercluster with eight known members. The second source, named the Double Irony, is a giant radio galaxy with a total length of about 1.1 Mpc. Its core coincides with a cataloged point-like X-ray source, but no extended X-ray emission from a surrounding galaxy cluster was detected. However, from the optical data we determined that the host is the brightest galaxy in a group that is younger, less virialized, and less massive than the Exemplar's cluster. A friends-of-friends analysis showed that the Double Irony's group is a member of the same supercluster as the Exemplar. There are indications that the jets and plumes of the Double Irony have been deflected by gas associated with the surrounding galaxy distribution. Another overdensity of galaxies (the tenth) containing a radio galaxy was found to be associated with the supercluster. Conclusions. Radio Galaxies can be used to find galaxy clusters/groups that are below the current sensitivity of X-ray surveys.
Radiation mechanisms: non-thermal
Radio continuum: galaxies
Galaxies: magnetic fields
Methods: data analysis
Galaxies: active
Author
Cathy Horellou
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
H. T. Intema
Leiden University
V. Smolcic
University of Zagreb
Andreas Nilsson
Student at Chalmers
F. Karlsson
Chalmers, Space, Earth and Environment
C. Krook
Chalmers, Space, Earth and Environment
L. Tolliner
Chalmers, Space, Earth and Environment
C. Adami
Laboratoire d'Astrophysique de Marseille
C. Benoist
Observatoire de la Cote d'Azur
M. Birkinshaw
University of Bristol
C. Caretta
Universidad de Guanajuato
L. Chiappetti
Istituto nazionale di astrofisica (INAF)
J. Delhaize
University of Zagreb
C. Ferrari
Observatoire de la Cote d'Azur
S. Fotopoulou
Durham University
V. Guglielmo
Max Planck Society
Istituto nazionale di astrofisica (INAF)
K. Kolokythas
Inter-University Centre for Astronomy and Astrophysics
F. Pacaud
University of Bonn
M. Pierre
University Paris-Saclay
B. M. Poggianti
Istituto nazionale di astrofisica (INAF)
M. E. Ramos-Ceja
University of Bonn
S. Raychaudhury
Inter-University Centre for Astronomy and Astrophysics
H. Rottgering
Leiden University
Cristian Vignali
Istituto nazionale di astrofisica (INAF)
University of Bologna
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 620 A19Subject Categories
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
Other Physics Topics
DOI
10.1051/0004-6361/201832972