Constraining strong lensing models with dynamics
Galaxy groups have an important role in the hierarchical assembly of structures in the Universe. Since galaxy groups are much more massive than galaxy-scale halos and are concentrated enough, they can act as lenses. The study of dark matter profiles can be very successfully using group-scale lenses, being that galaxy groups are quite abundant compared to galaxy clusters, and are easy to model. However, these have the disadvantage of the lack of constraints. In this talk, I will show how is possible to constrain the scale radius of the NFW profile using the velocity dispersion of the galaxy group. In particular I will present the results obtained with SL2SJ 02140-0535, a group which belongs to the Strong Lensing Legacy Survey - ARCS (SARCS) sample compiled from the final T0006 data release of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS).