The clustering of sub-mJy radio sources in the Bootes Deep Field

Abstract

We measure the angular clustering of ∼2000 radio sources in the Bootes Deep Field, covering 5.3 deg2 down to S1AGHZ = 0.2 mJy. With reference to work by Blake & Wall, we show that the size distribution of multi-component radio galaxies dominates the overall clustering signal, and that its amplitude extrapolates smoothly from their measurements above 5 mJy. The upper limits on any true galaxy-galaxy clustering are consistent with the clustering of sub-mJy radio-loud active galatic nuclei (AGN) being effectively diluted by the more weakly clustered IRAS-type starburst galaxies. Source count models imply that the survey contains ≃400 of the latter galaxies above 0. 2 mJy out to z ∼ 1-2. Measurement of their clustering must await their identification via the optical and infrared data due on this field.