Fitted angular size, θ (geometric mean), as a function of integrated flux density at 3 GHz. Unresolved sources fall below the red dotted line giving the minimum size of a source. The minimum size was derived using the envelope from Section 3.2. The blue shaded region shows the maximum size a source of a given integrated flux density can have before dropping below the peak brightness detection threshold, where the range reflects the range of rms noise in the 3 GHz image.