Paper detail

Describing galaxy weak lensing measurements from tenths to tens of Mpc and up to z~0.6 with a single model

The clustering of galaxies and the matter distribution around them can be described using the halo model complemented with a realistic description of the way galaxies populate dark matter haloes. This has been used successfully to describe statistical properties of samples of galaxies at z<0.2. Without adjusting any model parameters, we compare the predicted weak lensing signal induced by Luminous Red Galaxies to measurements from SDSS DR7 on much larger scales (up to ~90 h_{70}^{-1} Mpc) and at higher redshift (z~0.4). We find excellent agreement, suggesting that the model captures the main properties of the galaxy-dark matter connection. To extend the comparison to lenses at even higher redshifts we complement the SDSS data with shape measurements from the deeper RCS2, resulting in precise lensing measurements for lenses up to z~0.6. These measurements are also well described using the same model. Considering solely these weak lensing measurements, we robustly assess that, up to z~0.6, the number of central galaxies as a function of halo mass is well described by a log-normal distribution with scatter $σ_{\log L_{\rm c}}=0.146\pm0.011$, in agreement with previous independent studies at lower redshift. Our results demonstrate the value of complementing the information about the properties of the (lens) galaxies provided by SDSS with deeper, high-quality imaging data.