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

TL;DR

This paper demonstrates that a single halo model accurately describes galaxy weak lensing signals from small to large scales and up to redshift 0.6, combining SDSS and RCS2 data for comprehensive analysis.

Contribution

The study extends the halo model's applicability to higher redshifts and larger scales without parameter adjustments, validating its effectiveness across diverse datasets.

Findings

Excellent agreement between model predictions and SDSS DR7 measurements up to 90 Mpc

Consistent modeling of lensing signals up to z~0.6 using combined SDSS and RCS2 data

The central galaxy halo occupation follows a log-normal distribution with known scatter

Abstract

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 $\sigma_{\log L_{\rm c}}=0.146\pm0.011$, 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.