Baryon effects on the dark matter haloes constrained from strong gravitational lensing

Simulations are expected to be a powerful tool to investigate the baryon effects on dark matter (DM) haloes. Recent high resolution, cosmological hydrodynamic simulations predict that the inner density profiles of DM haloes depend systematically on the ratio of stellar to DM mass (M-*/M-halo), which is thought to be able to provide good fits to the observed rotation curves of galaxies. The Di Cintio et al. (hereafter DC14) profile is fitted from the simulations that are confined to M-halo <= 10(12) M-circle dot; in order to investigate the physical processes that may affect all haloes, we extrapolate it to much larger halo mass, including that of galaxy clusters. The inner slope of the DC14 profile is flat for low halo mass, it approaches 1 when the halo mass increases towards 10(12) M-circle dot and decreases rapidly after that mass. We use the DC14 profile for lenses and find that it predicts too few lenses compared with the most recent strong lensing observations Sloan Digital Sky Survey Quasar Lens Search (SQLS). We also calculate the strong lensing probabilities for a simulated density profile that continues the halo mass from the mass end of DC14 (similar to 10(12) M-circle dot) to the mass that covers the galaxy clusters, and find that this Schaller et al. (hereafter Schaller15) model predict too many lenses compared with other models and SQLS observations. Interestingly, Schaller15 profile has no core, however, like DC14, the rotation curves of the simulated haloes are in excellent agreement with observational data. Furthermore, we show that the standard two-population model SIS+NFW cannot match the most recent SQLS observations for large image separations.