Mass and luminosity of maxBCG galaxies groups

These data are intended to form the basis of future work on the formation of the m_12_ gap in galaxy groups and clusters. We use SDSS spectroscopy and g-, r- and i-band photometry to estimate galaxy group/cluster virial radii, masses and total luminosities.

In order to establish the robustness of our results, we compare them with literature studies that utilize a variety of mass determinations techniques (dynamical, X-ray and weak lensing) and total luminosities estimated in the B, r, i and K wavebands. We also compare our results to predictions derived from the Millennium Simulation. We find that, once selection effects are properly accounted for, excellent agreement exists between our results and the literature with the exception of a single observational study.