CFHTLenS and RCSLenS cross-correlation with Planck lensing detected in fourier and configuration space

Abstract

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 κ CMB κ gal and κ CMB γ t . Combining 747.2 deg 2 from both surveys, we find a detection significance that exceeds 4.2σ in both Fourier-and configuration-space analyses. Scaling the predictions by a free parameter A, we obtain A Planck CFHT = 0.68±0.31 and A Planck RCS = 1.31±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 publicly available.

Cross-correlating Planck tSZ with RCSLenS weak lensing: implications for cosmology and AGN feedback

“…Working with the shear directly in this way, instead of convergence, has the advantage that we skip the mass map reconstruction process and any noise and systematic issues that might be introduced during the process. We have successfully applied similar estimators previously to compute the cross-correlation of galaxy lensing with CMB lensing in Harnois-Déraps et al (2016). In principle, this estimator can be used for cross-correlations with any other scalar quantity.…”

“…A configuration-space analysis has the advantage that there are no complications introduced by the presence of masks, which significantly simplifies the analysis. As described in Harnois-Déraps et al (2016), a Fourier analysis requires extra considerations to account for the impact of several factors, including the convolution of the mask power spectrum and mode-mixing. On the other hand, a Fourier space analysis can be useful in distinguishing between different physical effects at different scales (e.g., the impact of baryon physics and AGN feedback).…”

Cross-correlation of weak lensing and gamma rays: implications for the nature of dark matter

“…Multi-band photometric information is not available for the whole RCSLenS footprint, therefore we use the redshift distribution estimation technique described in Harnois-Déraps et al (2016) and Hojjati et al (2016). Of the three magnitude cuts considered in Hojjati et al (2016), we choose to select the source galaxies such that 18 < mag r < 26, as this selection yielded the strongest cross-correlation signal in Hojjati et al (2016).…”

Looking through the same lens: Shear calibration for LSST, Euclid, and WFIRST with stage 4 CMB lensing

“…The constraints on shear bias are obtained by fixing cosmology and the photo-z bias to fiducial values. Crosscorrelations between galaxy shear and CMB lensing have been measured [59][60][61][62]. In [63], the combination of galaxy shear and CMB lensing is forecasted to improve dark energy and neutrino mass constraints.…”