Lofar deep fields: Probing a broader population of polarized radio galaxies in elais-n1
Journal article, 2021
We present deep polarimetric observations of the European Large Area ISO Survey-North 1 (ELAIS-N1) field using the Low Frequency Array (LOFAR) at 114.9-177.4 MHz. The ELAIS-N1 field is part of the LOFAR Two-metre Sky Survey deep fields data release I. For six eight-hour observing epochs, we align the polarization angles and stack the 20″-resolution Stokes Q, U-parameter data cubes. This produces a 16 deg2 image with 1σQU sensitivity of 26 μJy beam-1 in the central area. In this paper, we demonstrate the feasibility of the stacking technique, and we generate a catalog of polarized sources in ELAIS-N1 and their associated Faraday rotation measures (RMs). While in a single-epoch observation we detect three polarized sources, this number increases by a factor of about three when we consider the stacked data, with a total of ten sources. This yields a surface density of polarized sources of one per 1.6 deg2. The Stokes I images of three of the ten detected polarized sources have morphologies resembling those of FR I radio galaxies. This represents a greater fraction of this type of source than previously found, which suggests that more sensitive observations may help with their detection.
Galaxies: Individual: ELAIS-N1
Polarization
Radio continuum: Galaxies
Techniques: Polarimetric
Author
N. Herrera Ruiz
Ruhr-Universität Bochum
Shane P. O'Sullivan
Dublin City University
V. Vacca
Istituto nazionale di astrofisica (INAF)
V. Jelić
Ruder Boskovic Institute
B. Nikiel-Wroczyński
Jagiellonian University in Kraków
Stephen Bourke
Chalmers, Space, Earth and Environment, Onsala Space Observatory
J. Sabater
Royal Observatory
R. -J. Dettmar
Ruhr-Universität Bochum
G. Heald
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Cathy Horellou
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Sara Piras
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
C. Sobey
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
T. W. Shimwell
Netherlands Institute for Radio Astronomy (ASTRON)
C. Tasse
Centre national de la recherche scientifique (CNRS)
Rhodes University
Observatoire de Paris-Meudon
M. J. Hardcastle
University of Hertfordshire
R. Kondapally
Royal Observatory
K.T. Chyz̊y
Jagiellonian University in Kraków
M. Iacobelli
Netherlands Institute for Radio Astronomy (ASTRON)
P. N. Best
Royal Observatory
M. Brueggen
University of Hamburg
E. Carretti
Istituto nazionale di astrofisica (INAF)
I. Prandoni
Istituto nazionale di astrofisica (INAF)
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 648 A12Subject Categories
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
Geophysics
DOI
10.1051/0004-6361/202038896