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Related papers: Testing Shear Recovery with Field Distortion

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Flat-field images with thick, fully-depleted CCDs exhibit response variations near the edges of the chip and at other locations, such as the regoins bordering mid-frame blooming stop implants. Two possible origins for these repsonse…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Paul O'Connor

In this two-part article series we provide a generalized description of the scattering geometry of Bragg coherent diffraction imaging (BCDI) experiments, the shear distortion effects inherent to the resulting three-dimensional (3D) image…

Residual errors in shear measurements, after corrections for instrument systematics and atmospheric effects, can impact cosmological parameters derived from weak lensing observations. Here we combine convergence maps from our suite of…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-06 Andrea Petri , Morgan May , Zoltan Haiman , Jan M. Kratochvil

We investigate cosmological parameter inference from realistic simulated weak lensing image data using only galaxy position angles, as opposed to full-ellipticity information. We demonstrate that input shear fields can be accurately…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-30 Lee Whittaker

The Shear TEsting Programme, STEP, is a collaborative project to improve the accuracy and reliability of all weak lensing measurements in preparation for the next generation of wide-field surveys. In this first STEP paper we present the…

Noise bias is a significant source of systematic error in weak gravitational lensing measurements that must be corrected to satisfy the stringent standards of modern imaging surveys in the era of precision cosmology. This paper reviews the…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-09 Xiangchong Li , Rachel Mandelbaum , The LSST Dark Energy Science Collaboration

We outline how redshift-space distortions (RSD) can be measured from the angular correlation function w({\theta}), of galaxies selected from photometric surveys. The natural degeneracy between RSD and galaxy bias can be minimized by…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-18 Ashley J Ross , Will J Percival , Martin Crocce , Anna Cabre , Enrique Gaztanaga

We show, using the pseudo-$C_\ell$ technique, how to estimate cosmic shear and galaxy-galaxy lensing power spectra that are insensitive to the effects of multiple sources of lensing bias including source-lens clustering, magnification bias…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-12 Christopher A. J. Duncan , Michael L. Brown

We implement the Elliptical Gauss-Laguerre (EGL) galaxy-shape measurement method proposed by Bernstein & Jarvis (2002) and quantify the shear recovery accuracy in weak lensing analysis. This method uses a deconvolution fitting scheme to…

Astrophysics · Physics 2008-11-26 Reiko Nakajima , Gary Bernstein

Upcoming deep imaging surveys such as the Vera C. Rubin Observatory Legacy Survey of Space and Time will be confronted with challenges that come with increased depth. One of the leading systematic errors in deep surveys is the blending of…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-27 Erfan Nourbakhsh , J. Anthony Tyson , Samuel J. Schmidt , The LSST Dark Energy Science Collaboration

We describe and test the pipeline used to measure the weak lensing shear signal from the Kilo Degree Survey (KiDS). It includes a novel method of `self-calibration' that partially corrects for the effect of noise bias. We also discuss the…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Ian Fenech Conti , Ricardo Herbonnet , Henk Hoekstra , Julian Merten , Lance Miller , Massimo Viola

The weak distortions produced by gravitational lensing in the images of background galaxies provide a method to measure directly the distribution of mass in the universe. However this technique requires high precision measurements of the…

Astrophysics · Physics 2009-10-31 Jason Rhodes , Alexandre Refregier , Ed Groth

Lensing magnification and stacked shear measurements of galaxy clusters rely on measuring the density of background galaxies behind the clusters. The most common ways of measuring this quantity ignore the fact that some fraction of the sky…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Melanie Simet , Rachel Mandelbaum

We develop a new method to estimate gravitational shear by adopting an elliptical weight function to measure background galaxy images. In doing so, we introduce a new concept of "zero plane" which is an imaginal source plane where shapes of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Yuki Okura , Toshifumi Futamase

Weak gravitational lensing measurements based on photometry are limited by shape noise, the variance in the unknown unlensed orientations of the source galaxies. If the source is a disk galaxy with a well-ordered velocity field, however,…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-08 David Wittman , Matthew Self

The first half of this paper explores the origin of systematic biases in the measurement of weak gravitational lensing. Compared to previous work, we expand the investigation of PSF instability and fold in for the first time the effects of…

Fluorescence Correlation Spectroscopy (FCS) yields measurement parameters (number of molecules, diffusion time) that characterize the concentration and kinetics of fluorescent molecules within a supposedly known observation volume. Absolute…

Biological Physics · Physics 2011-12-23 Charles Edouard Leroux , Irène Wang , Jacques Derouard , Antoine Delon

We present a novel, model-independent technique for fitting the cross-component of weak lensing shear, $\gamma_\times$, along a line of sight by combining kinematic and photometric measurements of a single lensed galaxy. Rather than relying…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-26 Christopher Hopp , David Wittman

Precise calibration is a must for high reliance 3D computer vision algorithms. A challenging case is when the camera is behind a protective glass or transparent object: due to refraction, the image is heavily distorted; the pinhole camera…

Computer Vision and Pattern Recognition · Computer Science 2019-09-25 Szabolcs Pável , Csanád Sándor , Lehel Csató

Measurement of the gravitational distortion of images of distant galaxies is rapidly becoming established as a powerful probe of the dark mass distribution in clusters of galaxies. With the advent of large mosaics of CCD's these methods…

Astrophysics · Physics 2007-05-23 Nick Kaiser , Gordon Squires , Greg Fahlman , David Woods , Tom Broadhurst
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