LOFAR 26.6″ × 22.5″ resolution image. The contour levels are the same as those in Fig. 1 with σ = 240 μJy beam⁻¹. The blue compact-source-subtracted contour is drawn at 2σ, where σ = 335 μJy beam⁻¹ and the beam size is 45.7″ × 44.7″. The dashed black lines show the regions used to measure the flux densities from the diffuse cluster sources, and the measurements are summarised in Table 3.