Histograms for different samples – dashed, black lines with and without disks – and subsamples only with disks – solid, gray lines – as described in Sect. 5.3Subpanel at the top – Probable and possible members from Barrado y Navascués et al. (2004b) and Barrado y Navascués et al. (2007), with an initial selection based on optical photometry. Subpanel at the bottom – Members listed by Dolan & Mathieu (1999), originally selected from optical photometry (including narrow-band Hα – i.e., active stars or with accretion), and confirmed based on high-resolution spectroscopy.