English
Related papers

Related papers: Direct Shear Mapping - a new weak lensing tool

200 papers

We present a new method to measure the redshift-dependent galaxy bias by combining information from the galaxy density field and the weak lensing field. This method is based on Amara et al. (2012), where they use the galaxy density field to…

We present the first sample of galaxy clusters selected on the basis of their weak gravitational lensing shear. The shear induced by a cluster is a function of its mass profile and its redshift relative to the background galaxies being…

Weak lensing provides a direct measure of the distribution of mass in the universe, and is therefore a uniquely powerful probe of dark matter. Weak lensing can also be used to measure the twin phenomenon of dark energy, via its effect upon…

Astrophysics · Physics 2007-05-23 Richard Massey , Alexandre Refregier , Jason Rhodes

We study the prospects for three-dimensional mapping of the dark matter to high redshift through the shearing of faint galaxies images at multiple distances by gravitational lensing. Such maps could provide invaluable information on the…

Astrophysics · Physics 2009-08-12 Wayne Hu , Charles R. Keeton

Statistics of the weak lensing of galaxies can be used to constrain cosmology if the galaxy shear can be estimated accurately. In general this requires accurate modelling of unlensed galaxy shapes and the point spread function (PSF). I…

Astrophysics of Galaxies · Physics 2009-09-07 Antony Lewis

Strong gravitational lensing provides an independent measurement of the Hubble parameter ($H_0$). One remaining systematic is a bias from the additional mass due to a galaxy group at the lens redshift or along the sightline. We quantify…

Accurate photometric redshifts are among the key requirements for precision weak lensing measurements. Both the large size of the Sloan Digital Sky Survey (SDSS) and the existence of large spectroscopic redshift samples that are…

The Hubble constant ($H_0$), a crucial parameter in cosmology, quantifies the expansion rate of the universe so its precise measurement is important to understand the fundamental dynamics of our evolving universe. One of the major…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-29 Narayan Khadka , Simon Birrer , Alexie Leauthaud , Holden Nix

Weak lensing by large-scale structure is a powerful probe of cosmology if the apparent alignments in the shapes of distant galaxies can be accurately measured. We study the performance of a fully data-driven approach, based on…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-15 Henk Hoekstra

We study various measures of weak lensing distortions in future surveys, taking into account the noise arising from the finite survey size and the intrinsic ellipticity of galaxies. We also consider a realistic redshift distribution of the…

Astrophysics · Physics 2009-11-10 Patrick Valageas , Dipak Munshi , Andrew J. Barber

This paper details a description of the pattern of galaxy image distortion over the entire sky caused by the gravitational lensing which is the result of large scale inhomogeneities in our universe. We present a tensor spherical harmonic…

Astrophysics · Physics 2007-05-23 Albert Stebbins

Current and upcoming wide-field, ground-based, broad-band imaging surveys promise to address a wide range of outstanding problems in galaxy formation and cosmology. Several such uses of ground-based data, especially weak gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Rachel Mandelbaum , Christopher M. Hirata , Alexie Leauthaud , Richard J. Massey , Jason Rhodes

We use weak lensing data from the Hubble Space Telescope COSMOS survey to measure the second- and third-moments of the cosmic shear field, estimated from about 450,000 galaxies with average redshift <z> ~ 1.3. We measure two- and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Elisabetta Semboloni , Tim Schrabback , Ludovic van Waerbeke , Sanaz Vafaei , Jan Hartlap , Stefan Hilbert

Understanding and mitigating measurement systematics in weak lensing (WL) analysis requires large datasets of realistic galaxies with diverse morphologies and colors. Missions like Euclid, the Nancy Roman Space Telescope, and Vera C. Rubin…

Astrophysics of Galaxies · Physics 2025-06-09 Diana Scognamiglio , Jake H. Lee , Eric Huff , Sergi R. Hildebrandt , Shoubaneh Hemmati

Gravitational flexion, caused by derivatives of the gravitational tidal field, is potentially important for the analysis of the dark-matter distribution in gravitational lenses, such as galaxy clusters or the dark-matter haloes of galaxies.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Massimo Viola , Peter Melchior , Matthias Bartelmann

Cosmic shear statistics, such as the two-point correlation function (2PCF), can be evaluated with the PDF-SYM method instead of the traditional weighted-sum approach. It makes use of the full PDF information of the shear estimators, and…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-18 Zhenjie Liu , Jun Zhang , Hekun Li , Zhi Shen , Cong Liu

We study how joint shear and magnification measurements improve the statistical precision of weak lensing mass calibration experiments, relative to standard shear-only analysis. For our magnification measurements, we consider not only the…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-30 Eduardo Rozo , Fabian Schmidt

The weak gravitational lensing effect, small coherent distortions of galaxy images by means of a gravitational tidal field, can be used to study the relation between the matter and galaxy distribution. In this context, weak lensing has so…

Astrophysics · Physics 2014-11-18 P. Simon , P. Watts , P. Schneider , H. Hoekstra , M. D. Gladders , H. K. C. Yee , B. C. Hsieh , H. Lin

The analysis of strong lensing images usually involves an external convergence and shear, which are meant to model the effect of perturbations along the line of sight, on top of the main lens. Such a description of line-of-sight…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-04 Théo Duboscq , Natalie B. Hogg , Pierre Fleury , Julien Larena