The Effect of Weak Lensing on Distance Estimates from Supernovae

Understand

Using a sample of 608 Type Ia supernovae from the SDSS-II and BOSS surveys, combined with a sample of foreground galaxies from SDSS-II, we estimate the weak lensing convergence for each supernova line-of-sight.

• We find that the correlation between this measurement and the Hubble residuals is consistent with the prediction from lensing (at a significance of 1.7sigma.
• Strong correlations are also found between the residuals and supernova nuisance parameters after a linear correction is applied.
• When these other correlations are taken into account, the lensing signal is detected at 1.4sigma.