2001ApJ...558L..11H

We have measured the correlation between the lensing signal induced by (dark) matter and the number counts of galaxies on scales ranging from 0.15 to 3.0 h^–1₅₀ Mpc (which correspond to aperture radii of 1'-15'). This provides a direct probe of the scale dependence of the ratio of the classical bias parameter b and the galaxy-mass correlation coefficient r. The results presented here are based on 16 deg² of R_C-band data taken with the Canada-France-Hawaii Telescope as part of the Red-Sequence Cluster Survey. We used a sample of lens galaxies with 19.5<R_C<21 and a sample of source galaxies with 21.5<R_C<24. The results are consistent with a scale-independent value of b/r, which provides valuable constraints on models of galaxy formation on scales that can only be probed through weak lensing. For the currently favored cosmology (Ω_m=0.3, Ω_Λ=0.7), we find that b/r=1.05^+0.12_–0.10, similar to what is found on larger scales (∼10 h^–1₅₀ Mpc) from local dynamical estimates. These results support the hypothesis that light traces mass on scales ranging from 0.15 out to ∼10 h^–1₅₀ Mpc. The accuracy of the measurement will improve significantly in the coming years, enabling us to measure both b and r separately as a function of scale.