MeerKAT follow-up of enigmatic GLEAM 4-Jy (G4Jy) sources

TL;DR

This study used MeerKAT radio observations to analyze 140 GLEAM 4-Jy sources, classifying their morphology and identifying host galaxies, revealing diverse structures and some sources with ambiguous host identification despite high-resolution imaging.

Contribution

The paper provides detailed morphological classifications and host galaxy identifications for a large sample of radio sources using high-resolution MeerKAT data, improving understanding of their structures.

Findings

14 sources have WAT morphology

10 sources have head-tail morphology

98 host galaxies identified out of 140 sources

Abstract

We present the results from studying 140 radio sources in the GLEAM (GaLactic and Extragalactic All-sky MWA [Murchison Widefield Array]) 4-Jy (G4Jy) Sample. These sources were followed-up with MeerKAT to assess their radio morphology and enable host-galaxy identification, as existing radio images of 25 to 45-arcsec resolution do not provide sufficient information. We refer to these sources as the MeerKAT-2019 subset. The aim is to identify the host galaxy of these sources by visually inspecting the overlays comprising radio data from four surveys (at 150, 200, 843/1400, and 1300 MHz). Our morphological classification and host-galaxy identification relies upon the ~7-arcsec resolution images from MeerKAT (1300 MHz). Through the visual inspection of the overlays, 14 radio sources in the MeerKAT-2019 subset have wide-angle tail (WAT) morphology, 10 are head-tail, and 5 have X-, S-/Z-shaped morphology. Most of the remaining sources have the radio morphology of typical symmetric lobes. Of 140 sources, we find host galaxies for 98 sources, leaving 42 with no identified host galaxy. These 42 sources still have ambiguous identification even with higher resolution images from MeerKAT.