The Mass–Concentration Relation and the Stellar-to-halo Mass Ratio in the CFHT Stripe 82 Survey
Résumé
We present a new measurement of the mass–concentration relation and the stellar-to-halo mass ratio over the halo-mass range 5 × 10(12) to 2 × 10(14) M (⊙). 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: ${c}_{200c}(M)=A{\left(\tfrac{{M}_{200c}}{{M}_{0}}\right)}^{B}$ with 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.