Cosmological Constraints From Weak Lensing Peak Statistics With CFHT Stripe 82 Survey

Abstract

We derived constraints on cosmological parameters using weak lensing peak statistics measured on the $\sim 130{\mathrm{deg}}^2$ of the Canada-France-Hawaii Telescope Stripe 82 Survey (CS82). This analysis demonstrates the feasibility of using peak statistics in cosmological studies. For our measurements, we considered peaks with signal-to-noise ratio in the range of $\hat{I}½=[3,6]$. For a flat $\hat{I}›$CDM model with only $(\hat{I}{\text{c◯}}_{\mathrm{m}},\ddot{I}{ƒ}_8)$ as free parameters, we constrained the parameters of the following relation $\hat{I}{\pounds }_8=\ddot{I}{ƒ}_8(\hat{I}{\text{c◯}}_{\mathrm{m}}/0.27{)}^{\hat{I}}\pm$ to be: $\hat{I}{\pounds }_8=0.82\pm 0.03$ and $\hat{I}\pm =0.43\pm 0.02$. The $\hat{I}\pm$ value found is considerably smaller than the one measured in two-point and three-point cosmic shear correlation analyses, showing a significant complement of peak statistics to standard weak lensing cosmological studies. The derived constraints on $(\hat{I}{\text{c◯}}_{\mathrm{m}},\ddot{I}{ƒ}_8)$ are fully consistent with the ones from either WMAP9 or Planck. From the weak lensing peak abundances alone, we obtained marginalised mean values of $\hat{I}{\text{c◯}}_{\mathrm{m}}=0.38_{-0.24}^{+0.27}$ and $\ddot{I}{ƒ}_8=0.81\pm 0.26$. Finally, we also explored the potential of using weak lensing peak statistics to constrain the mass-concentration relation of dark matter halos simultaneously with cosmological parameters.

17 pages, 11 figures, MNRAS in press