Revisiting the alignment of radio galaxies in the ELAIS-N1 field

Abstract

Aims. Previous studies reported an alignment of the major axes of radio galaxies on various angular scales. Here, we study the alignment of radio galaxies in the ELAIS-N1 Low Frequency ARray (LOFAR) deep field, which covers an area of 25 $\mathrm{de}{\mathrm{g}}^2$. \newline Methods. The low noise level of about 20$\mu Jy/beam$ of the LOFAR deep field observations at 150 MHz enabled the identification of 447 extended ($>30{}^{\prime \prime }$) radio galaxies for which we have measured the major axis position angle. We found that 95\% of these sources have either photometric or spectroscopic redshifts, which we then used for a three-dimensional analysis. \newline Results. We show the distribution of the position angles of radio galaxies in the ELAIS-N1 field and perform multiple statistical tests to check whether the radio galaxies are randomly oriented. We found that the distribution of position angles is consistent with being uniform. Two peaks around position angles of 50 and 140$\mathrm{deg}$ are spurious and are not caused by an alignment, as shown by a 3D analysis. In conclusion, our results do not support a 2D or 3D alignment of radio galaxies on scales smaller than $\sim 4\mathrm{deg}$.

10 pages, 6 figures, 2 tables Accepted for publication in A&A

References in corpus (26)

• The unWISE Catalog: Two Billion Infrared Sources from Five Years of WISE Imaging
• The Last of FIRST: The Final Catalog and Source Identifications
• The CatWISE2020 Catalog
• The Clustering of DESI-like Luminous Red Galaxies Using Photometric Redshifts
• WISE x SuperCOSMOS photometric redshift catalog: 20 million galaxies over 3pi steradians
• The LOFAR Two Metre Sky Survey: Deep Fields Data Release 1 -- III. Host-galaxy identifications and value added catalogues
• Spin alignments of spiral galaxies within the large-scale structure from SDSS DR7
• All-purpose, all-sky photometric redshifts for the Legacy Imaging Surveys Data Release 8
• Alignment of quasar polarizations with large-scale structures
• Giant radio galaxies - II. Tracers of large-scale structure
• Alignment of galaxies relative to their local environment in SDSS-DR8
• SDSS-IV MaNGA: 3D spin alignment of spiral and S0 galaxies
• Alignment between filaments and galaxy spins from the MaNGA integral-field survey
• Photometric redshifts for galaxies in the Subaru Hyper Suprime-Cam and unWISE and a catalogue of identified clusters of galaxies
• The polarization in the JVAS/CLASS flat-spectrum radio sources: II. A search for aligned radio polarizations
• Radio Galaxy Zoo: Cosmological Alignment of Radio Sources
• Giant radio quasars: sample and basic properties
• MIGHTEE-HI: The relation between the HI gas in galaxies and the cosmic web
• Giant radio galaxies in the LoTSS Boötes deep field
• Accretion disk versus jet orientation in H${}_2$O megamaser galaxies
• Correlated orientations of the axes of large quasar groups on Gpc scales
• Alignment in the orientation of LOFAR radio sources
• Local alignments of parsec-scale AGN radiojets
• The alignment between brightest cluster galaxies and host clusters
• Global alignments of parsec-scale AGN radio jets and their polarization planes
• Anisotropic correlation functions as tracers of central galaxy alignments in simulations

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