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


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 A19

Subject Categories

Astronomy, Astrophysics and Cosmology

Atom and Molecular Physics and Optics

Other Physics Topics



More information

Latest update