Redshift distribution of initially selected member galaxies in the galaxy cluster S1101. All visible galaxies were initially selected by as described in Sect. 3.3. Estimators of location and scale (z_cl and σ, respectively; see Beers et al. 1990) were used to clip interlopers. The resulting cluster galaxy candidates are indicated by the shaded histogram, while the blue vertical lines refer to the ± 3σ interval of σ_cl around z_cl used for the clipping.