Left: the black line shows the 10 second-binned PN light curve in the 0.3−10 keV band for the field F04. The beginning of the observation was affected by flaring. The green curve shows the light curve after the two-step cleaning (see Sect. 2), which safely removed all contaminated time intervals. Right: examples of the detection pipeline products for field F04 in the 0.5−2 keV band of the PN detector: a) counts image, b) double-component background model, c) binary detection mask, d) reconstruction of all the detected sources. The green circle (2 arcmin radius) marks the cluster ID 018.