The Super-CLASS GMRT catalogue - SCG

DOI

We present the results of 325MHz Giant Metrewave Radio Telescope observations of a supercluster field, known to contain five Abell clusters at redshift z~0.2. We achieve a nominal sensitivity of 34uJy/beam towards the phase centre. We compile a catalogue of 3257 sources with flux densities in the range 183uJy-1.5Jy within the entire ~6.5deg^2^ field of view. Subsequently, we use available survey data at other frequencies to derive the spectral index distribution for a sub-sample of these sources, recovering two distinct populations - a dominant population which exhibit spectral index trends typical of steep-spectrum synchrotron emission, and a smaller population of sources with typically flat or rising spectra. We identify a number of sources with ultrasteep spectra or rising spectra for further analysis, finding two candidate high-redshift radio galaxies and three gigahertz-peaked-spectrum radio sources. Finally, we derive the Euclidean-normalized differential source counts using the catalogue compiled in this work, for sources with flux densities in excess of 223uJy. Our differential source counts are consistent with both previous observations at this frequency and models of the low-frequency source population. These represent the deepest source counts yet derived at 325MHz. Our source counts exhibit the well-known flattening at mJy flux densities, consistent with an emerging population of star-forming galaxies; we also find marginal evidence of a downturn at flux densities below 308uJy, a feature so far only seen at 1.4GHz.

Cone search capability for table J/MNRAS/462/917/scg (The 325MHz source population of the Super-CLASS field (full table 4))

Identifier
DOI http://doi.org/10.26093/cds/vizier.74620917
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/MNRAS/462/917
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/462/917
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/462/917
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/MNRAS/462/917
Provenance
Creator Riseley C.J.; Scaife A.M.M.; Hales C.A.; Harrison I.; Birkinshaw M.,Battye R.A.; Beswick R.J.; Brown M.L.; Casey C.M.; Chapman S.C.,Demetroullas C.; Hung C.-L.; Jackson N.J.; Muxlow T.; Watson B.
Publisher CDS
Publication Year 2017
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; Galactic and extragalactic Astronomy; Natural Sciences; Observational Astronomy; Physics