LOFAR stacked image of 11 frequency bands resulting in an effective central frequency of 143 MHz and a 34 MHz bandwidth. The lowest contour level corresponds to 3σ significance. The contour levels are drawn at (−2, 2, 4, 8, etc.) times 2.7 mJy beam⁻¹. The rms is 3.1 mJy beam⁻¹. The beam size (shown in the bottom left corner) is 0.459″ × 0.308″ with a position angle of −39.1°. The images of the individual bands are available at the CDS.