Hardness ratio vs. -log  probability of the Kolmogorov-Smirnov test for the same clusters in the Fig. 2. The larger blue circles indicate the 22 clusters presented in this paper. The lower left sector enclosed by dashed lines is the zone where there is a high chance that a source is not a cluster. We note that this is a conservative limit, and any source that falls into this category must be scrutinised in detail to be confirmed. One cluster indicated by a blue circle that has an exceptionally soft emission among all of the 22 (the large blue circle nearest to the vertical dashed line) is RXCJ2149.9-1859. See Sect. 4.3 for detailed remarks about this source. Two clusters of small extent are clearly compact clusters where there is a central dominant galaxy close to the X-ray centres.