The GLEAM 4-Jy (G4Jy) Sample: II. Host-galaxy identification for individual sources

Abstract

The entire southern sky (Declination, $\delta <$ 30 deg) has been observed using the Murchison Widefield Array (MWA), which provides radio imaging of $\sim$2-arcmin resolution at low frequencies (72-231 MHz). This is the GaLactic and Extragalactic All-sky MWA (GLEAM) Survey, and we have previously used a combination of visual inspection, cross-checks against the literature, and internal matching to identify the 'brightest' radio-sources ($S_{151MHz}>$ 4 Jy) in the extragalactic catalogue (Galactic latitude, $|b|>$ 10 deg). We refer to these 1,863 sources as the GLEAM 4-Jy (G4Jy) Sample, and use radio images (of $\le$ 45-arcsec resolution), and multi-wavelength information, to assess their morphology and identify the galaxy that is hosting the radio emission (where appropriate). Details of how to access all of the overlays used for this work are available at https://github.com/svw26/G4Jy. Alongside this we conduct further checks against the literature, which we document in this paper for individual sources. Whilst the vast majority of the G4Jy Sample are active galactic nuclei with powerful radio-jets, we highlight that it also contains a nebula, two nearby, star-forming galaxies, a cluster relic, and a cluster halo. There are also three extended sources for which we are unable to infer the mechanism that gives rise to the low-frequency emission. In the G4Jy catalogue we provide mid-infrared identifications for 86% of the sources, and flag the remainder as: having an uncertain identification (129 sources), having a faint/uncharacterised mid-infrared host (126 sources), or it being inappropriate to specify a host (2 sources). For the subset of 129 sources, there is ambiguity concerning candidate host-galaxies, and this includes four sources (B0424$-$728, B0703$-$451, 3C 198, and 3C 403.1) where we question the existing identification.

37 pages (24 MB in size), 23 figures, 3 tables, accepted for publication in PASA, and now updated to match the final proof. Full-resolution images will be used for the published version, available through the journal

References in corpus (21)

• GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey I: A low-frequency extragalactic catalogue
• The Molonglo Galactic Plane Survey (MGPS-2): Compact Source Catalogue
• Deep ATLAS radio observations of the CDFS-SWIRE field
• A Unified Catalog of Radio Objects Detected by NVSS, FIRST, WENSS, GB6, and SDSS
• Minkowski's Object: A Starburst Triggered by a Radio Jet, Revisited
• An XMM-Newton study of the environments, particle content and impact of low-power radio galaxies
• Classifying Radio Galaxies with Convolutional Neural Network
• On the relationship between a giant radio galaxy MSH 05-22 and the ambient large-scale galaxy structure
• Giant radio galaxies - II. Tracers of large-scale structure
• NGC 326: X-shaped no more
• Optical and radio properties of extragalactic radio sources with recurrent jet activity
• MRC B0319-454: Probing the large-scale structure with a giant radio galaxy
• The Sub-parsec Scale Radio Properties of Southern Starburst Galaxies. I. Supernova Remnants, the Supernova Rate, and the Ionised Medium in the NGC 253 Starburst
• The first Murchison Widefield Array low frequency radio observations of cluster scale non-thermal emission: the case of Abell 3667
• Jet Speeds in Wide Angle Tailed Radio Galaxies
• Neutral hydrogen and magnetic fields in M83 observed with the SKA Pathfinder KAT-7
• Early Science with the Karoo Array Telescope: a Mini-Halo Candidate in Galaxy Cluster Abell 3667
• NGC 741 - Mergers and AGN feedback on galaxy group scale
• Cosmological evolution of the Fanaroff-Riley type II source population
• Automated Cross-identifying Radio to Infra-red Surveys Using the LRPY Algorithm: A Case Study
• 3C 40 in Abell 194: can tail radio galaxies exist in a quiescent cluster?

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