Left: GMRT 325 MHz radio contours of the emission from A 1758N at the full resolution (10.5′′ × 8.4′′, p.a. 58°), overlaid on the POSS-2 red image. The 1σ noise level is 0.1 mJy beam^-1. Red contours start at 0.4 mJy beam^-1 and scale by a factor of 2. Black dashed contours correspond to the − 3σ level. Individual radio galaxies are labelled from S1 to S5. Right: 325 MHz contours of the giant radio halo overlaid on the smoothed Chandra X-ray image. The radio image has been obtained after subtracting the discrete embedded sources (S1 to S5), whose position is marked as green crosses. The restoring beam is 35.0′′ × 35.0′′, p.a. 0°. The 1σ is 0.4 mJy beam^-1. White contours start at + 3σ = 0.12 mJy beam^-1 and scale by a factor 2. The − 3σ level is shown as red dashed contours.