Parameter likelihood of intrinsic ellipticity correlations

Abstract

Subject of this paper are the statistical properties of ellipticity alignments between galaxies evoked by their coupled angular momenta. Starting from physical angular momentum models, we bridge the gap towards ellipticity correlations, ellipticity spectra and derived quantities such as aperture moments, comparing the intrinsic signals with those generated by gravitational lensing, with the projected galaxy sample of EUCLID in mind. We investigate the dependence of intrinsic ellipticity correlations on cosmological parameters and show that intrinsic ellipticity correlations give rise to non-Gaussian likelihoods as a result of nonlinear functional dependencies. Comparing intrinsic ellipticity spectra to weak lensing spectra we quantify the magnitude of their contaminating effect on the estimation of cosmological parameters and find that biases on dark energy parameters are very small in an angular-momentum based model in contrast to the linear alignment model commonly used. Finally, we quantify whether intrinsic ellipticities can be measured in the presence of the much stronger weak lensing induced ellipticity correlations, if prior knowledge on a cosmological model is assumed.

14 pages, 8 figures, submitted to MNRAS

References in corpus (11)

• Dark energy constraints from cosmic shear power spectra: impact of intrinsic alignments on photometric redshift requirements
• Angular momentum and galaxy formation revisited
• Systematic Bias in Cosmic Shear: Beyond the Fisher Matrix
• Optimal Surveys for Weak Lensing Tomography
• The impact of baryons on the spins and shapes of dark matter haloes
• The removal of shear-ellipticity correlations from the cosmic shear signal via nulling techniques
• Error analysis in cross-correlation of sky maps: application to the ISW detection
• The phenomenological approach to modeling the dark energy
• Biases on the cosmological parameters and thermal SZ residuals
• Evolution of intrinsic ellipticity correlations due to peculiar motion
• Intrinsic alignment boosting: Direct measurement of intrinsic alignments in cosmic shear data

Cited by in corpus (13)

• Cosmology with cosmic shear observations: a review
• Intrinsic alignments of SDSS-III BOSS LOWZ sample galaxies
• CFHTLenS: Cosmological constraints from a combination of cosmic shear two-point and three-point correlations
• Galaxy alignments: Theory, modelling and simulations
• Angular ellipticity correlations in a composite alignment model for elliptical and spiral galaxies and inference from weak lensing
• Intrinsic alignments and 3d weak gravitational lensing
• The cross-correlation between 3d cosmic shear and the integrated Sachs-Wolfe effect
• Intrinsic and extrinsic correlations of galaxy shapes and sizes in weak lensing data
• 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
• Statistical separation of weak gravitational lensing and intrinsic ellipticities based on galaxy colour information
• Intrinsic and extrinsic gravitational flexions
• Realistic systematic biases induced by residual intrinsic alignments in cosmic shear surveys