Statistical properties of filaments in weak gravitational lensing

We study the weak lensing properties of filaments that connect clusters of galaxies through large cosmological N-body simulations. We select 4639 halo pairs with masses higher than 10(14) h(-1)M(circle dot) from the simulations and investigate dark matter distributions between two haloes with ray-tracing simulations. In order to classify filament candidates, we estimate convergence profiles and perform profile fitting. We find that matter distributions between haloes can be classified in a plane of fitting parameters, which allows us to select straight filaments from the ray-tracing simulations. We also investigate the statistical properties of these filaments, finding them to be consistent with previous studies. We find that 35 per cent of halo pairs possess straight filaments, 4 per cent of which can be detected directly at signal-to-noise ratio S/N >= 2 with weak lensing. Furthermore, we study the statistical properties of haloes at the edges of filaments. We find that haloes are preferentially elongated along filamentary structures and are less massive with increasing filament mass. However, the dependence of these halo properties on the masses of straight filaments is very weak.