Weak gravitational lensing of intrinsically aligned galaxies

Abstract

Subject of this paper is the weak lensing effect on galaxies that show intrinsically correlated ellipticities. In our model, we investigate the distortion of the ellipticity field if the galaxies experience an apparent shift in their position by weak lensing deflection and compare this effect to the shearing effect induced by tidal fields. Starting with a derivation of intrinsic ellipticity spectra by employing a tidal torquing model generating galactic angular momenta, we model the galaxy ellipticity by assuming that the galactic disk forms perpendicularly to the host halo angular momentum direction and derive intrinsic ellipticity E-mode and B-mode spectra from the angular momentum statistics. The lensing effect on the ellipticity field is modeled by employing the methodology developed in the framework of lensing of the cosmic microwave background polarisation. For EUCLID, ellipticity correlations are altered by lensing deflection on multipoles l>1000 by ~5% for the ellipticity E-modes and by ~30% for the B-modes, while a shallower survey would exhibit larger changes on larger angular scales. In addition to the convolving effect of lensing on the ellipticity spectra we investigate the E/B-mode conversion, and discuss the possibility of measuring correlations between different multipoles which is evoked by the homogeneity breaking effect of the lensing displacement. Our conclusion is that although shape correlations generated by weak gravitational shear is dominant, the shifting effect due to lensing is shaping the ellipticity spectra on small angular scales and causes a number of interesting phenomena, which might be observable by future surveys.

10 pages, 7 figures, submitted to MNRAS

References in corpus (14)

• CFHTLenS tomographic weak lensing cosmological parameter constraints: Mitigating the impact of intrinsic galaxy alignments
• Dark energy constraints from cosmic shear power spectra: impact of intrinsic alignments on photometric redshift requirements
• The Evolution of Dark Matter Halo Properties in Clusters, Filaments, Sheets and Voids
• Intrinsic galaxy alignments from the 2SLAQ and SDSS surveys: luminosity and redshift scalings and implications for weak lensing surveys
• Constraints on intrinsic alignment contamination of weak lensing surveys using the MegaZ-LRG sample
• Optimal Surveys for Weak Lensing Tomography
• The removal of shear-ellipticity correlations from the cosmic shear signal via nulling techniques
• The Gravitational Shear--Intrinsic Ellipticity Correlation Functions of Luminous Red Galaxies in Observation and in the $\Lambda$CDM Model
• Cosmic vorticity and the origin of halo spins
• Sources of contamination to weak lensing three-point statistics: constraints from N-body simulations
• The Nonlinear Evolution of Galaxy Intrinsic Alignments
• Comparison between the Blue and the Red Galaxy Alignments Detected in the Sloan Digital Sky Survey
• 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 (14)

• KiDS-450: Cosmological parameter constraints from tomographic weak gravitational lensing
• Galaxy alignments: An overview
• The Intrinsic Alignment of Galaxies and its Impact on Weak Gravitational Lensing in an Era of Precision Cosmology
• Galaxy alignments: Theory, modelling and simulations
• Deflection of light by black holes and massless wormholes in massive gravity
• 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
• Lensing observables: Massless dyonic vis-à-vis Ellis wormhole
• Investigation of the orientation of galaxies in clusters: the importance, methods and results of research
• Intrinsic and extrinsic correlations of galaxy shapes and sizes in weak lensing data
• The distribution of galaxies gravitational field stemming from their tidal interaction
• Dynamical Tidal Locking Theory: A new source of the Spin of Dark Matter Halos
• Pure-mode correlation functions for cosmic shear and application to KiDS-1000
• The non-Gaussian distribution of galaxies gravitational fields