Short-spacing corrected total intensity images of NGC 4565 at 1.5 and 6 GHz. The synthesised beam FWHM is 12″ in panels a and b, and in panels c and d. The rms noise σ is 20 μJy beam⁻¹ in panel a, 7.0 μJy beam⁻¹ in panel b, and 2.5 μJy beam⁻¹ in panels c and d. All individual VLA maps have been PB corrected before short-spacing corrections were applied. Contour levels are σ × (3, 6, 12, 24, etc). The 3σ contours near the edges of the C-band maps are due to the radially increasing noise levels after PB correction. Panel d: same map as panel c, but zoomed in on the ring-shaped central part of the radio disc. Filled black circles indicate the size of the synthesised beam.