Dark matter halo properties from galaxy-galaxy lensing

Understand

We present results for a galaxy-galaxy lensing study based on imaging data from the Canada-France-Hawaii Telescope Legacy Survey Wide.

• From a 12 million object multi-colour catalogue for 124 deg^2 of photometric data in the u*g'r'i'z' filters we compute photometric redshifts (with a scatter of \sigma_{\Delta z/(1+z)} = 0.033 and an outlier rate of \eta=2.0 per cent for i'<=22.5) and extract galaxy shapes down to i'=24.0.
• We select a sample of lenses and sources with 0.05 < z_d <= 1 and 0.05 < z_s <= 2.
• We fit three different galaxy halo profiles to the lensing signal, a singular isothermal sphere (SIS), a truncated isothermal sphere (BBS) and a universal density profile (NFW).