CFHTLenS and RCSLenS Cross-Correlation with Planck Lensing Detected in
  Fourier and Configuration Space
  We measure the cross-correlation signature between the Planck CMB lensing map
and the weak lensing observations from both the Red-sequence Cluster Lensing
Survey (RCSLenS) and the Canada-France-Hawai Telescope Lensing Survey
(CFHTLenS). In addition to a Fourier analysis, we include the first
configuration-space detection, based on the estimators $\langle \kappa_{\rm
CMB} \kappa_{\rm gal} \rangle$ and $\langle \kappa_{\rm CMB} \gamma_{t}
\rangle$. Combining 747.2 deg$^2$ from both surveys, we find a detection
significance that exceeds $4.2\sigma$ in both Fourier- and configuration-space
analyses. Scaling the predictions by a free parameter $A$, we obtain $A^{\rm
Planck}_{\rm CFHT}= 0.68\pm 0.31 $ and $A^{\rm Planck}_{\rm RCS}= 1.31\pm
0.33$. In preparation for the next generation of measurements similar to these,
we quantify the impact of different analysis choices on these results. First,
since none of these estimators probes the exact same dynamical range, we
improve our detection by combining them. Second, we carry out a detailed
investigation on the effect of apodization, zero-padding and mask
multiplication, validated on a suite of high-resolution simulations, and find
that the latter produces the largest systematic bias in the cosmological
interpretation. Finally, we show that residual contamination from intrinsic
alignment and the effect of photometric redshift error are both largely
degenerate with the characteristic signal from massive neutrinos, however the
signature of baryon feedback might be easier to distinguish. The three lensing
datasets are now publicly available.
