A new method to measure galaxy bias by combining the density and weak lensing fields

Abstract

We present a new method to measure the redshift-dependent galaxy bias by combining information from the galaxy density field and the weak lensing field. This method is based on Amara et al. (2012), where they use the galaxy density field to construct a bias-weighted convergence field kg. The main difference between Amara et al. (2012) and our new implementation is that here we present another way to measure galaxy bias using tomography instead of bias parameterizations. The correlation between kg and the true lensing field k allows us to measure galaxy bias using different zero-lag correlations, such as <kgk>/<kk> or <kgkg>/<kgk>. Our method measures the linear bias factor on linear scales under the assumption of no stochasticity between galaxies and matter. We use the MICE simulation to measure the linear galaxy bias for a flux-limited sample (i < 22.5) in tomographic redshift bins using this method. This paper is the first that studies the accuracy and systematic uncertainties associated with the implementation of the method, and the regime where it is consistent with the linear galaxy bias defined by projected 2-point correlation functions (2PCF). We find that our method is consistent with linear bias at the percent level for scales larger than 30 arcmin, while nonlinearities appear at smaller scales. This measurement is a good complement to other measurements of bias, since it does not depend strongly on sigma8 as the 2PCF measurements. We apply this method to the Dark Energy Survey Science Verification data in a follow-up paper.

15 pages, 9 figures

References in corpus (8)

• An algorithm to build mock galaxy catalogues using MICE simulations
• The onion universe: all sky lightcone simulations in spherical shells
• Wide-Field InfraRed Survey Telescope (WFIRST) Final Report
• The assembly bias of dark matter haloes to higher orders
• Measuring the growth of matter fluctuations with third-order galaxy correlations
• GaBoDS: The Garching-Bonn Deep Survey: VII. Probing galaxy bias using weak gravitational lensing
• Galaxy bias from the Dark Energy Survey Science Verification data: combining galaxy density maps and weak lensing maps
• RCSLenS: A new estimator for large-scale galaxy-matter correlations

Cited by in corpus (13)

• Large-Scale Galaxy Bias
• Unveiling $\nu$ secrets with cosmological data: neutrino masses and mass hierarchy
• Dark Energy Survey Year 1 Results: Curved-Sky Weak Lensing Mass Map
• Two- and three-dimensional wide-field weak lensing mass maps from the Hyper Suprime-Cam Subaru Strategic Program S16A data
• Testing the lognormality of the galaxy and weak lensing convergence distributions from Dark Energy Survey maps
• Dark Energy Survey Year 3 results: cosmology with moments of weak lensing mass maps -- validation on simulations
• Scale dependence of galaxy biasing investigated by weak gravitational lensing: An assessment using semi-analytic galaxies and simulated lensing data
• Linear and non-linear bias: predictions vs. measurements
• Galaxy bias from the Dark Energy Survey Science Verification data: combining galaxy density maps and weak lensing maps
• Cross-correlating 21 cm and galaxy surveys: implications for cosmology and astrophysics
• Wavelet reconstruction of E and B modes for CMB polarisation and cosmic shear analyses
• Galaxy bias from galaxy-galaxy lensing in the DES Science Verification Data
• Searching for Dark Structures: A Comparison of Weak-lensing Convergence Maps and Lensing-weighted Galaxy Density Maps