NGC 4666 C-band image (C- and D-configuration) in gray scale with an rms noise σ of 4.6 μJy beam⁻¹ and a beam size of 3.0″ × 3.5″ (see bottom left), using robust zero weighting. The light-gray contours show the inner region with the radio point source from the same data. The corresponding flux densities are 0.22, 0.44, and 0.88 mJy beam⁻¹. We note the bubble-like structure in the eastern direction from the point source and the filamentary structures (threads) in the northern halo.