Comparison of weak lensing by NFW and Einasto halos and systematic errors

Understand

Recent N-body simulations have shown that Einasto radial profiles provide the most accurate description of dark matter halos.

• Predictions based on the traditional NFW functional form may fail to describe the structural properties of cosmic objects at the percent level required by precision cosmology.
• We computed the systematic errors expected for weak lensing analyses of clusters of galaxies if one wrongly models the lens density profile.
• Even though the NFW fits of observed tangential shear profiles can be excellent, viral masses and concentrations of very massive halos (>~ 10^{15}M_Sun/h) can be over- and underestimated by ~10 per cent, respectively.