1. LOFAR Deep Fields: probing a broader population of polarized radio galaxies in ELAIS-N1
- Author
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George Heald, C. Tasse, V. Vacca, Błażej Nikiel-Wroczyński, Isabella Prandoni, R.-J. Dettmar, Stephen Bourke, Charlotte Sobey, N. Herrera Ruiz, Martin J. Hardcastle, Vibor Jelić, Marco Iacobelli, J. Sabater, Shane O'Sullivan, S. Piras, R. Kondapally, Krzysztof T. Chyzy, Timothy W. Shimwell, Ettore Carretti, Marcus Brüggen, Philip Best, and Cathy Horellou
- Subjects
Radio galaxy ,media_common.quotation_subject ,Population ,Polarimetry ,FOS: Physical sciences ,Astrophysics ,Low frequency ,01 natural sciences ,symbols.namesake ,0103 physical sciences ,Faraday effect ,polarimetric [techniques] ,education ,010303 astronomy & astrophysics ,individual: ELAIS-N1 [galaxies] ,media_common ,Physics ,education.field_of_study ,polarization ,010308 nuclear & particles physics ,Astronomy and Astrophysics ,LOFAR ,galaxies: individual: ELAIS-N1 ,radio continuum: galaxies ,techniques: polarimetric ,Polarization (waves) ,Astrophysics - Astrophysics of Galaxies ,galaxies [radio continuum] ,Space and Planetary Science ,Sky ,Astrophysics of Galaxies (astro-ph.GA) ,symbols - Abstract
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., Comment: This paper is part of the 1st data release of the LoTSS Deep Fields. Accepted for publication in A&A. 14 pages, 9 figures, 7 tables
- Published
- 2021