Histogram of pixels of the S/N map, where pixels with noise >0.3 mJy beam⁻¹ have been removed. The red dashed line is the best Gaussian fit. The green dashed line is indicative and shows where the pixel brightness distribution moves away from the Gaussian fit. This is also the 4.2σ level corresponding to a peak flux of 0.76 mJy for a typical noise per beam of 0.18 mJy. The solid black line corresponds to our peak threshold of 4.8σ (0.86 mJy).