Statistical separation of weak gravitational lensing and intrinsic ellipticities based on galaxy colour information

Abstract

Intrinsic alignments of galaxies are recognised as one of the most important systematic in weak lensing surveys on small angular scales. In this paper we investigate ellipticity correlation functions that are measured separately on elliptical and spiral galaxies, for which we assume the generic alignment mechanisms based on tidal shearing and tidal torquing, respectively. Including morphological information allows to find linear combinations of measured ellipticity correlation functions which suppress the gravitational lensing signal completely or which show a strongly boosted gravitational lensing signal relative to intrinsic alignments. Specifically, we find that $(i)$ intrinsic alignment spectra can be measured in a model-independent way at a significance of $\Sigma \simeq 60$ with a wide-angle tomographic survey such as Euclid's, $(ii)$ intrinsic alignment model parameters can be determined at percent-level precision, $(iii)$ this measurement is not impeded by misclassifying galaxies and assuming a wrong alignment model, $(iv)$ parameter estimation from a cleaned weak lensing spectrum is possible with almost no bias and $(v)$ the misclassification would not strongly impact parameter estimation from the boosted weak lensing spectrum.

References in corpus (78)

• Weak Gravitational Lensing
• Stable clustering, the halo model and nonlinear cosmological power spectra
• CFHTLenS tomographic weak lensing cosmological parameter constraints: Mitigating the impact of intrinsic galaxy alignments
• Intrinsic alignment-lensing interference as a contaminant of cosmic shear
• Cosmology with cosmic shear observations: a review
• Probing the Universe with Weak Lensing
• Weak Gravitational Lensing by Large-Scale Structure
• Intrinsic and Extrinsic Galaxy Alignment
• Weak Gravitational Lensing and its Cosmological Applications
• Power Spectrum Tomography with Weak Lensing
• Measuring the dark side (with weak lensing)
• Planck 2015 results. XIV. Dark energy and modified gravity
• Cosmic Structure Growth and Dark Energy
• Cosmology with Weak Lensing Surveys
• Spin induced galaxy alignments and their implications for weak lensing measurements
• Galaxy alignments: An overview
• The Intrinsic Alignment of Galaxies and its Impact on Weak Gravitational Lensing in an Era of Precision Cosmology
• Detection of large scale intrinsic ellipticity-density correlation from the Sloan Digital Sky Survey and implications for weak lensing surveys
• Weak lensing surveys and the intrinsic correlation of galaxy ellipticities
• Discriminating weak lensing from intrinsic spin correlations using the curl-gradient decomposition
• Weak Lensing and Dark Energy
• Evolution of the angular momentum of protogalaxies from tidal torques: Zel'dovich approximation
• Beyond linear galaxy alignments
• Intrinsic alignments of SDSS-III BOSS LOWZ sample galaxies
• Systematic Bias in Cosmic Shear: Beyond the Fisher Matrix
• Galaxy alignments: Observations and impact on cosmology
• Review: galactic angular momenta and angular momentum correlations in the cosmological large-scale structure
• The WiggleZ Dark Energy Survey: Direct constraints on blue galaxy intrinsic alignments at intermediate redshifts
• Galaxy alignments: Theory, modelling and simulations
• Angular Momentum Acquisition in Galaxy Halos
• Weak lensing with COMBO-17: estimation and removal of intrinsic alignments
• Weak gravitational lensing: reducing the contamination by intrinsic alignments
• Tidal alignment of galaxies
• Galaxy Spin Statistics and Spin-Density Correlation
• Dark Energy Constraints from Weak Lensing Cross-Correlation Cosmography
• The impact of intrinsic alignment on current and future cosmic shear surveys
• Testing the tidal alignment model of galaxy intrinsic alignment
• Comprehensive Two-Point Analyses of Weak Gravitational Lensing Surveys
• Suppressing the contribution of intrinsic galaxy alignments to the shear two-point correlation function
• Tomography of lensing cross power spectra
• Intrinsic alignment of simulated galaxies in the cosmic web: implications for weak lensing surveys
• Theoretical Estimates of Intrinsic Galaxy Alignment
• The Cosmological Impact of Intrinsic Alignment Model Choice for Cosmic Shear
• Power Spectra Estimation for Weak Lensing
• Intrinsic galaxy shapes and alignments II: Modelling the intrinsic alignment contamination of weak lensing surveys
• Separating intrinsic alignment and galaxy-galaxy lensing
• Intrinsic galaxy shapes and alignments I: Measuring and modelling COSMOS intrinsic galaxy ellipticities
• Weak lensing, dark matter and dark energy
• The Impact of Intrinsic Alignments: Cosmological Constraints from a Joint Analysis of Cosmic Shear and Galaxy Survey Data
• Nulling Tomography with Weak Gravitational Lensing
• Testing dark energy paradigms with weak gravitational lensing
• Correlations of Cosmic Tidal Fields
• Intrinsic alignments in the cross-correlation of cosmic shear and CMB weak lensing
• Constraining Modified Gravity with Euclid
• Galactic angular momenta and angular momentum couplings in the large-scale structure
• Biases on the cosmological parameters and thermal SZ residuals
• Intrinsic alignment contamination to CMB lensing-galaxy weak lensing correlations from tidal torquing
• Tomographic weak lensing shear spectra from large N-body and hydrodynamical simulations
• 3D Weak Gravitational Lensing of the CMB and Galaxies
• Non-linear weak lensing forecasts
• Disentangling dark energy and cosmic tests of gravity from weak lensing systematics
• Angular ellipticity correlations in a composite alignment model for elliptical and spiral galaxies and inference from weak lensing
• Calibration of colour gradient bias in shear measurement using HST/CANDELS data
• Intrinsic alignments and 3d weak gravitational lensing
• Weak lensing tomography with orthogonal polynomials
• A proposal on the galaxy intrinsic alignment self-calibration in weak lensing surveys
• Controlling intrinsic-shear alignment in three-point weak lensing statistics
• Cosmic magnification: nulling the intrinsic clustering signal
• Optimising cosmic shear surveys to measure modifications to gravity on cosmic scales
• Parameter likelihood of intrinsic ellipticity correlations
• Measuring the scale dependence of intrinsic alignments using multiple shear estimates
• Parameter constraints from weak lensing tomography of galaxy shapes and cosmic microwave background fluctuations
• A theoretical estimate of intrinsic ellipticity bispectra induced by angular momenta alignments
• The power spectrum of systematics in cosmic shear tomography and the bias on cosmological parameters
• Non-linear evolution of the tidal angular momentum of protostructures II: non-Gaussian initial conditions
• Do angular momentum induced ellipticity correlations contaminate weak lensing measurements?
• Probing Dark Energy with Lensing Magnification in Photometric Surveys
• Probe combination in large galaxy surveys : Application of Fisher information and Shannon entropy to weak lensing

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• Intrinsic correlations of galaxy sizes in a hydrodynamical cosmological simulation
• Cosmic shear beyond 2-point statistics: Accounting for galaxy intrinsic alignment with projected tidal fields
• Dusty Clump Survival in Supernova Ejecta: Dust-Mediated Growth vs. Crushing by the Reverse Shock
• Realistic systematic biases induced by residual intrinsic alignments in cosmic shear surveys