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Related papers: Intrinsic Shear and Galaxy Alignments: A Quantitat…

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We consider the effect of galaxy intrinsic alignments (IAs) on dark energy constraints from weak gravitational lensing. We summarise the latest version of the linear alignment model of IAs, following the brief note of Hirata & Seljak (2010)…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Donnacha Kirk , Anais Rassat , Ole Host , Sarah Bridle

Gravitational lensing causes background galaxy images to become aligned, and the statistical characteristics of the image alignments can then be used to constrain the power spectrum of mass fluctuations. Analyses of gravitational lensing…

Astrophysics · Physics 2017-08-23 A. F. Heavens

We present a model for the intrinsic alignment contamination of the shear three-point correlation function and skewness of the mass aperture statistic using the tidal alignment and tidal torquing (TATT) formalism. We compute the intrinsic…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-15 Rafael C. H. Gomes , Kyle Miller , Sunao Sugiyama , Jonathan Blazek , Thomas Bakx , Bhuvnesh Jain

The subject of this paper is to build a physical model describing shape and size correlations of galaxies due to weak gravitational lensing and due to direct tidal interaction of elliptical galaxies with gravitational fields sourced by the…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-22 Basundhara Ghosh , Ruth Durrer , Bjoern Malte Schaefer

We study the parameter estimation bias induced by intrinsic alignments on a Euclid-like weak lensing survey. For the intrinsic alignment signal we assume a composite alignment model for elliptical and spiral galaxies using tidal shearing…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-15 Robert Reischke , Björn Malte Schäfer

We use galaxies from the IllustrisTNG, MassiveBlack-II and Illustris hydrodynamic simulations to investigate the behaviour of large scale galaxy intrinsic alignments. Our analysis spans four redshift slices over the approximate range of…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-22 S. Samuroff , R. Mandelbaum , J. Blazek

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…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-04 Tim M. Tugendhat , Robert Reischke , Bjoern Malte Schaefer

Intrinsically aligned galaxy shapes are one of the most important systematics in cosmic shear measurements. So far theoretical studies of intrinsic alignments almost exclusively focus on their statistics at the two-point level. Results from…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Philipp M. Merkel , Bjoern Malte Schaefer

Intrinsic alignments (IAs) of galaxies are an important contaminant for cosmic shear studies, but the modelling is complicated by the dependence of the signal on the source galaxy sample. In this paper, we use the halo model formalism to…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-16 Maria Cristina Fortuna , Henk Hoekstra , Benjamin Joachimi , Harry Johnston , Nora Elisa Chisari , Christos Georgiou , Constance Mahony

The intrinsic alignment (IA) of observed galaxy shapes with the underlying cosmic web is a source of contamination in weak lensing surveys. Sensitive methods to identify the IA signal will therefore need to be included in the upcoming weak…

In cosmological analyses it is common to combine different types of measurement from the same survey. In this paper we use simulated DES Y3 and LSST Y1 data to explore differences in sensitivity to intrinsic alignments (IA) between cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-12 S. Samuroff , A. Campos , A. Porredon , J. Blazek

We present measurements of the intrinsic alignments (IAs) of the star-forming gas of galaxies in the EAGLE simulations. Radio continuum imaging of this gas enables cosmic shear measurements complementary to optical surveys. We measure the…

Astrophysics of Galaxies · Physics 2022-02-16 Alexander D. Hill , Robert A. Crain , Ian G. McCarthy , Shaun T. Brown

To reach the full potential for the next generation of weak lensing surveys, it is necessary to mitigate the contamination of intrinsic alignments (IA) of galaxies in the observed cosmic shear signal. The self calibration (SC) of intrinsic…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-27 Ji Yao , Eske M. Pedersen , Mustapha Ishak , Pengjie Zhang , Anish Agashe , Haojie Xu , Huanyuan Shan

Intrinsic alignments of galaxies can mimic to an extent the effects of shear caused by weak gravitational lensing. Previous studies have shown that for shallow surveys with median redshifts z_m = 0.1, the intrinsic alignment dominates the…

Astrophysics · Physics 2009-11-07 Catherine Heymans , Alan Heavens

The intrinsic alignment (IA) of galaxies has been shown to be a significant barrier to precision cosmic shear measurements. (Zhang, 2010, ApJ, 720, 1090) proposed a self-calibration technique for the power spectrum to calculate the induced…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 M. A. Troxel , Mustapha Ishak

Cosmic shear leads to a correlation of the observed ellipticities of galaxies, an effect which is used to place constraints on cosmological parameters, and to explore the evolution of dark matter and dark energy in the universe. However, a…

Astrophysics · Physics 2009-11-11 Lindsay King

Intrinsic alignments (IA), correlations between the intrinsic shapes and orientations of galaxies on the sky, are both a significant systematic in weak lensing and a probe of the effect of large-scale structure on galactic structure and…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-18 Denise M. Schmitz , Christopher M. Hirata , Jonathan Blazek , Elisabeth Krause

We present a complete forward model of a realistic weak lensing galaxy catalogue based on the 740 Mpc hydrodynamical MillenniumTNG (MTNG) simulation. Starting with a complete particle and cell lightcone covering one octant of the sky with…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-23 Fulvio Ferlito , Volker Springel , Christopher T. Davies , Toshiki Kurita , Ana Maria Delgado , Sownak Bose , Lars Hernquist

We explore the possibility that an intrinsic correlation between galaxy ellipticities arising during the galaxy formation process may account for part of the shear signal recently reported by several groups engaged in weak lensing surveys.…

Astrophysics · Physics 2009-07-28 Rupert A. C. Croft , Chris Metzler

The intrinsic alignment (IA) of galaxies is a major astrophysical contaminant to weak gravitational lensing measurements, and the study of its dependence on galaxy properties helps provide meaningful physical priors that aid cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-16 Christos Georgiou , Nora Elisa Chisari , Maciej Bilicki , Francesco La Barbera , Nicola R. Napolitano , Nivya Roy , Crescenzo Tortora