10C continued: a deeper radio survey at 15.7 GHz
  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
flat-spectrum cores of radio galaxies contributing more significantly to the
counts than predicted by the models.
