Stacked source detection on an observation split into several nearly equally long sub-exposures (obs. id. 0555780201). Upper panel: percentage of exposure time. Middle panel: sliding box detections that are submitted to emldetect. Cross-hatched bars mark those found in the fifteen mosaics of all sub-exposures, dark filled bars the detections found when running eboxdetect on all individual images simultaneously, and light filled bars the box detections in each individual sub-exposure. Lower panel: final maximum-likelihood detections with a minimum total detection likelihood of at least six in the stack (dark blue) and in the individual sub-exposures (light blue). The dashed horizontal line marks the result of source detection on the full, unsplit observation.