Quantifying angular clustering in wide-area radio surveys

We quantify the angular clustering of radio galaxies in the NVSS and FIRST surveys using the two-point correlation function and the moments of counts-in-cells — both important points of comparison with theory. These investigations consistently demonstrate that the slope of the correlation function for radio galaxies agrees with that for optically selected galaxies, γ≈ 1.8. We describe how to disentangle the imprint of galaxy clustering from the two observational problems: resolution of radio galaxies into multiple components and gradients in source surface density induced by difficulties in processing ‘snapshot’ radio observations (significant in both surveys below S1.4GHz∼ 15 mJy). This study disagrees in some respects with previous analyses of the angular clustering of radio galaxies.