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Related papers: Weak gravitational lensing: reducing the contamina…

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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

Weak gravitational lensing is now established as a powerful method to measure mass fluctuations in the universe. It relies on the measurement of small coherent distortions of the images of background galaxies. Even low-level correlations in…

Astrophysics · Physics 2009-07-09 Alan Heavens , Alexandre Refregier , Catherine Heymans

Galaxy shapes are not randomly oriented, rather they are statistically aligned in a way that can depend on formation environment, history and galaxy type. Studying the alignment of galaxies can therefore deliver important information about…

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

Cosmic shear constrains cosmology by exploiting the apparent alignments of pairs of galaxies due to gravitational lensing by intervening mass clumps. However galaxies may become (intrinsically) aligned with each other, and with nearby mass…

Astrophysics · Physics 2009-06-23 Sarah Bridle , Lindsay King

The intrinsic alignments of galaxies, i.e., the correlation between galaxy shapes and their environment, are a major source of contamination for weak gravitational lensing surveys. Most studies of intrinsic alignments have so far focused on…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-19 William d'Assignies D. , Nora Elisa Chisari , Nico Hamaus , Sukhdeep Singh

Accurate measurements of the cosmic shear signal require a separation of the true weak gravitational lensing signal from intrinsic shape correlations of galaxies. These `intrinsic alignments' of galaxies originate from galaxy formation…

Astrophysics of Galaxies · Physics 2020-10-19 Jolanta Zjupa , Björn Malte Schäfer , Oliver Hahn

Correlations between the intrinsic shapes of galaxies and the large-scale galaxy density field provide an important tool to investigate galaxy intrinsic alignments, which constitute a major astrophysical systematic in cosmological weak…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-01 B. Joachimi , R. Mandelbaum , F. B. Abdalla , S. L. Bridle

Intrinsic alignments are believed to be a major source of systematics for future generation of weak gravitational lensing surveys like Euclid or LSST. Direct measurements of the alignment of the projected light distribution of galaxies in…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-15 Sandrine Codis , Yohan Dubois , Christophe Pichon , Julien Devriendt , Adrianne Slyz

Gravitational lensing induces significant errors in the measured distances to high-redshift standard candles and standard sirens such as type-Ia supernovae, gamma-ray bursts, and merging supermassive black hole binaries. There will…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Stefan Hilbert , Jonathan R. Gair , Lindsay J. King

Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are…

Astrophysics · Physics 2009-09-29 D. Munshi , P. Valageas , L. Van Waerbeke , A. Heavens

The intrinsic alignment of galaxies constitutes the major astrophysical source of systematic errors in surveys of weak gravitational lensing by the large-scale structure. We discuss the principles, summarise the implementation, and…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-13 B. Joachimi , P. Schneider

The power spectrum of weak lensing shear caused by large-scale structure is an emerging tool for precision cosmology, in particular for measuring the effects of dark energy on the growth of structure at low redshift. One potential source of…

During the past few years, secure detections of cosmic shear have been obtained, manifest in the correlation of the observed ellipticities of galaxies. Constraints have already been placed on cosmological parameters, such as the…

Astrophysics · Physics 2009-11-07 Lindsay King , Peter Schneider

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

Kinematic weak lensing describes the distortion of a galaxy's projected velocity field due to lensing shear, an effect recently reported for the first time by Gurri et al. based on a sample of 18 galaxies at $z \sim 0.1$. In this paper, we…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-08 Brian DiGiorgio , Kevin Bundy , Kyle B. Westfall , Alexie Leauthaud , David Stark

In this paper we show how intrinsic alignments can be incorporated consistently in the formalism of 3d weak lensing. We use two different descriptions of the intrinsic galaxy ellipticities, the so-called linear and quadratic model,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Philipp M. Merkel , Bjoern Malte Schaefer

In this third paper of a series on radio weak lensing for cosmology with the Square Kilometre Array, we scrutinise synergies between cosmic shear measurements in the radio and optical/near-IR bands for mitigating systematic effects. We…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Stefano Camera , Ian Harrison , Anna Bonaldi , Michael L. Brown

(Abridged) Weak gravitational lensing induces distortions on the images of background galaxies, and thus provides a direct measure of mass fluctuations in the universe. Since the distortions induced by lensing on the images of background…

Astrophysics · Physics 2009-10-31 David Bacon , Alexandre Refregier , Douglas Clowe , Richard Ellis

We examine cosmological constraints from high precision weak lensing surveys including super-sample covariance (SSC) due to the finite survey volume. Specifically, we focus on the contribution of {\it beat coupling} in the intrinsic…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-04 Saeed Ansarifard , S. M. S. Movahed