Cross-Correlation of CFHTLenS Galaxy Number Density and Planck CMB Lensing

Abstract

We measure the cross-power spectrum between galaxy density from Canada-France-Hawaii-Telescope Lensing Survey (CFHTLenS) catalogues and gravitational lensing convergence from Planck data release 1 (2013) and 2 (2015). We investigate three main galaxy samples: $18.0<i_{\mathrm{AB}}<22.0$, $18.0<i_{\mathrm{AB}}<23.0$, $18.0<i_{\mathrm{AB}}<24.0$ in the redshift range $0.2<z<1.3$ in each of the four CFHTLenS wide fields. By comparing the measured cross-spectrum with model predictions, linear galaxy-dark matter biases of $b=0.82_{-0.23}^{+0.24},0.83_{-0.18}^{+0.19},0.82_{-0.14}^{+0.16}$ are inferred at significances of $3.5,4.5,5.6\sigma$ using the Planck 2015 release. These measurements are marginally consistent with biases derived from galaxy-galaxy auto-correlations: $b=1.15_{-0.01}^{+0.02},1.08_{-0.01}^{+0.01}$ and $0.96_{-0.01}^{+0.01}$ respectively. Using the 2013 Planck release, we obtain biases of $b=1.33_{-0.28}^{+0.29},1.19_{-0.23}^{+0.23},1.16_{-0.18}^{+0.19}$, showing significant differences between the releases.