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Related papers: Intrinsic and extrinsic gravitational flexions

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The measurement of the integrated optical polarization of weakly gravitationally lensed galaxies can provide considerable constraints on lens models. The method outlined depends on fact that the orientation of the direction of optical…

Astrophysics · Physics 2009-10-30 Edouard Audit , John F. L. Simmons

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

We address the problem of deriving, from the observed projected metallicity gradients, the intrinsic metallicity distribution of elliptical galaxies as a function of their integrals of motion. The method is illustrated by an application to…

Astrophysics · Physics 2009-09-25 L. Ciotti , M. Stiavelli , A. Braccesi

We show that galaxy ellipticity estimation for weak gravitational lensing with unweighted image moments reduces to the problem of measuring a combination of the means of three independent normal random variables. Under very general…

Instrumentation and Methods for Astrophysics · Physics 2018-12-12 Nicolas Tessore , Sarah Bridle

Alignments in the angular momentum vectors of galaxies can induce large scale correlations in their projected orientations. Such alignments arise from the tidal torques exerted on neighboring proto-galaxies by the smoothly varying shear…

Astrophysics · Physics 2009-11-06 Priyamvada Natarajan , Robert G. Crittenden , Ue-Li Pen , Tom Theuns

The observed properties of galaxies vary with inclination; for most applications we would rather have properties that are independent of inclination, intrinsic properties. One way to determine inclination corrections is to consider a large…

Astrophysics · Physics 2009-06-23 Ariyeh H. Maller , Andreas A. Berlind , Michael R. Blanton , David W. Hogg

We use the Illustris simulation to study the distributions of ellipticities and kinematic misalignments of galactic projections, as well as the intrinsic shapes and rotation of the simulated galaxies. Our results for the projections of…

Astrophysics of Galaxies · Physics 2019-08-14 Lisiyuan Yang , Dandan Xu , Shude Mao , Volker Springel , Hongyu Li

The intrinsic alignment of galaxies is a key factor in modeling weak-lensing observations and can serve as a valuable signal for both cosmological and astrophysical studies. Modelling this signal requires understanding how galaxy shapes…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-16 Francisco Maion , Jens Stücker , Raul E. Angulo

Intrinsic alignments of galaxies have been shown to contaminate weak gravitational lensing observables on linear scales, $r>$ 10 $h^{-1}$Mpc, but studies of alignments in the non-linear regime have thus far been inconclusive. We present an…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-29 Nora Elisa Chisari , Rachel Mandelbaum , Michael A. Strauss , Eric Huff , Neta Bahcall

We develop an analytic model for galaxy intrinsic alignments (IA) based on the theory of tidal alignment. We calculate all relevant nonlinear corrections at one-loop order, including effects from nonlinear density evolution, galaxy biasing,…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-19 Jonathan Blazek , Zvonimir Vlah , Uroš Seljak

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

Gravitational lensing shear has the potential to be the most powerful tool for constraining the nature of dark energy. However, accurate measurement of galaxy shear is crucial and has been shown to be non-trivial by the Shear TEsting…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 L. M. Voigt , S. L. Bridle

We estimate the amplitude of the source-lens clustering bias and of the intrinsic-alignment bias of weak lensing estimators of the two-point and three-point convergence and cosmic-shear correlation functions. We use a linear galaxy bias…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-17 Patrick Valageas

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…

The observables in a strong gravitational lens are usually just the image positions and sometimes the flux ratios. We develop a new and simple algorithm which allows a set of models to be fitted exactly to the observations. Taking our cue…

Astrophysics · Physics 2008-11-26 N. W. Evans , H. J. Witt

Studies of strong gravitational lensing in current and upcoming wide and deep photometric surveys, and of stellar kinematics from (integral-field) spectroscopy at increasing redshifts, promise to provide valuable constraints on galaxy…

Astrophysics · Physics 2015-05-13 Glenn van de Ven , Rachel Mandelbaum , Charles R. Keeton

We have previously reported the discovery of strong gravitational lensing by faint elliptical galaxies using the WFPC2 on HST and here we investigate their potential usefulness in putting constraints on lens mass models. We compare various…

Astrophysics · Physics 2009-11-06 Adam Knudson , Kavan U. Ratnatunga , Richard E. Griffith

We investigate the impact of the observed correlation between a galaxies shape and its surrounding density field on the measurement of third order weak lensing shear statistics. Using numerical simulations, we estimate the systematic error…

The distortion field defined by the ellipticities of galaxy shapes projected on the sky can be uniquely decomposed into a gradient and a curl component. If the observed ellipticities are induced by weak gravitational lensing, then the…

Astrophysics · Physics 2011-09-30 Robert G. Crittenden , Priyamvada Natarajan , Ue-Li Pen , Tom Theuns

An overview is given on those theoretical gravitational lensing results that can be formulated in a spacetime setting, without assuming that the gravitational fields are weak and that the bending angles are small. The first part is devoted…

General Relativity and Quantum Cosmology · Physics 2016-11-15 Volker Perlick
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