The Mass-Concentration Relation and the Stellar-to-halo Mass Ratio in the CFHT Stripe 82 Survey

We present a new measurement of the mass-concentration relation and the stellar-to-halo mass ratio over the halo-mass range 5 x 10(12) to 2 x 10(14) M circle dot. To achieve this, we use weak lensing measurements from the Canada-France-Hawaii Telescope Stripe 82 Survey (CS82), combined with the central galaxies from the redMaPPer cluster catalog and the LOWZ/CMASS galaxy sample of the Sloan Digital Sky Survey-III Baryon Oscillation Spectroscopic Survey Tenth Data Release. The stacked lensing signals around these samples are modeled as a sum of contributions from the central galaxy, its dark matter halo, and the neighboring halos, as well as a term for possible centering errors. We measure the mass-concentration relation: c(200c) (M) = A (M-200c/M-0)(B) A = 5.24 +/- 1.24, B = -0.13 +/- 0.10 for 0.2 < z < 0.4, and A = 6.61 +/- 0.75, B = -0.15 +/- 0.05 for 0.4 < z < 0.6. These amplitudes and slopes are completely consistent with predictions from recent simulations. We also measure the stellar-to-halo mass ratio for our samples, and find results consistent with previous measurements from lensing and other techniques.