University of Hertfordshire

From the same journal

From the same journal

By the same authors

LOFAR Deep Fields: Probing a broader population of polarized radio galaxies in ELAIS-N1

Research output: Contribution to journalArticlepeer-review


  • 2011.08292v1

    Accepted author manuscript, 1.79 MB, PDF document

  • N. Herrera Ruiz
  • S. P. O'Sullivan
  • V. Vacca
  • V. Jelić
  • B. Nikiel-Wroczyński
  • S. Bourke
  • J. Sabater
  • R. -J. Dettmar
  • G. Heald
  • C. Horellou
  • S. Piras
  • C. Sobey
  • T. W. Shimwell
  • C. Tasse
  • R. Kondapally
  • K. T. Chyży
  • M. Iacobelli
  • P. N. Best
  • M. Brüggen
  • E. Carretti
  • I. Prandoni
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Original languageEnglish
Article numberA12
Number of pages13
JournalAstronomy & Astrophysics
Publication statusPublished - 7 Apr 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 deg$^2$ image with 1$\sigma_{\rm QU}$ sensitivity of 26 $\mu$Jy/beam 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 deg$^2$. 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.


This paper is part of the 1st data release of the LoTSS Deep Fields. © 2020 The European Southern Observatory (ESO).

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