10C continued: a deeper radio survey at 15.7 GHz
Monthly Notices of the Royal Astronomical Society
Oxford University Press
MetadataShow full item record
Whittam, I., Riley, J., Green, D., Davies, M., Franzen, T., Rumsey, C., Schammel, M., & et al. (2016). 10C continued: a deeper radio survey at 15.7 GHz. Monthly Notices of the Royal Astronomical Society, 457 1496-1506. https://doi.org/10.1093/mnras/stv2960
We present deep 15.7-GHz observations made with the Arcminute Microkelvin Imager Large Array in two fields previously observed as part of the Tenth Cambridge (10C) survey. These observations allow the source counts to be calculated down to 0.1 mJy, a factor of five deeper than achieved by the 10C survey. The new source counts are consistent with the extrapolated fit to the 10C source count, and display no evidence for either steepening or flattening of the counts. There is thus no evidence for the emergence of a significant new population of sources (e.g. starforming) at 15.7 GHz flux densities above 0.1 mJy, the flux density level at which we expect starforming galaxies to begin to contribute. Comparisons with the de Zotti et al. model and the SKADS Simulated Sky show that they both underestimate the observed number of sources by a factor of two at this flux density level. We suggest that this is due to the flatspectrum cores of radio galaxies contributing more significantly to the counts than predicted by the models.
galaxies: active, radio continuum: galaxies, catalogues, surveys
We thank the staff of the Mullard Radio Astronomy Observatory for maintaining and operating AMI. IHW and CR acknowledge Science and Technology Facilities Council studentships. IHW acknowledges support from the Square Kilometre Array South Africa project and the South African National Research Foundation. This research has made use of NASA’s Astrophysics Data System. We thank the referee for their careful reading of this manuscript.
Embargo Lift Date
External DOI: https://doi.org/10.1093/mnras/stv2960
This record's URL: https://www.repository.cam.ac.uk/handle/1810/253144