LoTSS DR2 visual classifications

DOI

The LOw Frequency ARray Two-metre Sky Survey second data release (LoTSS DR2) covers 27% of the northern sky and contains around four million radio sources. The development of this catalogue involved a large citizen science project (Radio Galaxy Zoo: LOFAR) with more than 116,000 resolved sources going through visual inspection. We took a subset of sources with flux density above 75mJy and an angular size of 90" or greater, giving a total of 9985 sources or ~10% of the visually inspected sources. We classified these by visual inspection in terms of broad source type (e.g., Fanaroff-Riley class I or II, narrow or wide-angle tail, relaxed double), noticeable features (wings, visible jets, banding, filaments etc), environmental features (cluster environment, merger, diffuse emission). Our specific aim was to search for features linked to jet precession, such as a misaligned jet axis, curvature and multiple hotspots. This combination of features and morphology allowed us to detect increasingly fine-grained sub- populations of interesting or unusual sources. We found that 28% of sources showed evidence of one or more precession indicators, which could make them candidates for hosting close binary supermassive black holes. Potential precession signatures occur in sources of all sizes and luminosities in our sample but appear to favour more massive host galaxies. Our work greatly expands the sample size and parameter space of searches for precession signatures in powerful jetted sources. This work also showcases the diversity of large bright radio sources in the LOFAR surveys, whether or not precession indicators are present.

Cone search capability for table J/A+A/699/A338/catalog (Visual classifications and precession indicators for extended radio sources from LoTSS DR2)

Identifier
DOI http://doi.org/10.26093/cds/vizier.36990338
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/699/A338
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/699/A338
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/699/A338
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/A+A/699/A338
Provenance
Creator Horton M.A.; Hardcastle M.J.; Miley G.K.; Tasse C.; Shimwell T.
Publisher CDS
Publication Year 2025
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Cosmology; Galactic and extragalactic Astronomy; Interstellar medium; Natural Sciences; Observational Astronomy; Physics