(Top panel) Passbands for the different filters used in this study. Filled curves show the HST filters while open curves show the CFHT filters. Note that the K_s filter is only available for the six galaxies that fall inside the ﹩2\,\deg \times \,2\,\deg ﹩ region around M87. (Bottom panel) Model spectra for selected SSPs using the BC03 models with a Chabrier IMF. Three different ages are shown: 2, 5, and 10 Gyr (blue, green, and red lines, respectively). Solid lines denote SSPs with solar metallicity, while dotted lines correspond to populations with half solar metallicity. The spectra have been normalized at 1.6 μm in the F160W filter.