Distribution of the event peak thermal energy for the SAS250W data set for a temperature of 220 000 K, assuming the depth D of the O V emission along the line of sight. (a) Equal to the event length along the slit (top panel). (b) Constant, equal to 3.36″ (middle panel). (c) Proportional to 1/length (bottom panel). The straight lines in all panels are power-law fits obtained separately for the population of one-pixel events (on the left) and the population of longer events with two or more pixels (on the right). The power index is given in Table 2. The energy along the X-axis is an upper limit derived with f = 1 (see Sects. 4.4 and 4.6 for a discussion).