Cross-correlating Planck CMB lensing with SDSS: Lensing-lensing and galaxy-lensing cross-correlations

TL;DR

This study cross-correlates Planck CMB lensing maps with SDSS galaxy lensing and galaxy catalogs to measure cosmological parameters, galaxy bias, and lensing signals, confirming consistency with Planck 2015 cosmology.

Contribution

It provides new measurements of galaxy bias, matter density, and lensing cross-correlations using combined CMB and galaxy lensing data, with results consistent with Planck 2015 cosmology.

Findings

Galaxy bias for LOWZ: 1.75±0.04

Galaxy bias for CMASS: 1.95±0.02

Cosmological distance ratio: 2.68±0.29

Abstract

We present results from cross-correlating Planck CMB lensing maps with the Sloan Digital Sky Survey (SDSS) galaxy lensing shape catalog and BOSS galaxy catalogs. For galaxy position vs. CMB lensing cross-correlations, we measure the convergence signal around the galaxies in configuration space, using the BOSS LOWZ ($z\sim0.30$) and CMASS ($z\sim0.57$) samples. With fixed Planck 2015 cosmology, doing a joint fit with the galaxy clustering measurement, for the LOWZ (CMASS) sample we find a galaxy bias $b_g=1.75\pm0.04$ ($1.95\pm 0.02$) and galaxy-matter cross-correlation coefficient $r_{cc}=1.0\pm0.2$ ($0.8\pm 0.1$) using $20<r_p<70h^{-1}$Mpc, consistent with results from galaxy-galaxy lensing. Using the same scales and including the galaxy-galaxy lensing measurements, we constrain $\Omega_m=0.284\pm0.024$ and relative calibration bias between the CMB lensing and galaxy lensing to be $b_\gamma=0.82^{+0.15}_{-0.14}$. The combination of galaxy lensing and CMB lensing also allows us to measure the cosmological distance ratios (with $z_l\sim0.3$, $z_s\sim0.5$) $\mathcal R=\frac{D_s D_{l,*}}{D_* D_{l,s}}=2.68\pm0.29$, consistent with predictions from the Planck 2015 cosmology ($\mathcal R=2.35$). We detect the galaxy position-CMB convergence cross-correlation at small scales, $r_p<1h^{-1}$Mpc, and find consistency with lensing by NFW halos of mass $M_h\sim10^{13}h^{-1}M_\odot$. Finally, we measure the CMB lensing-galaxy shear cross-correlation, finding an amplitude of $A=0.76\pm0.23$ ($z_\text{eff}=0.35$, $\theta<2^\circ$) with respect to Planck 2015 $\Lambda$CDM predictions ($1\sigma$-level consistency). We do not find evidence for relative systematics between the CMB and SDSS galaxy lensing.