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Related papers: Weak Lensing Simulations for the SKA

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The Square Kilometre Array's Low Frequency instrument (SKA-LOW) will be the most sensitive aperture array ever used for radio astronomy, and will operate in the under-sampled regime for most of the frequency band where grating-lobes pose…

Instrumentation and Methods for Astrophysics · Physics 2016-12-28 Benjamin Mort , Fred Dulwich , Nima Razavi-Ghods , Eloy de Lera Acedo , Keith Grainge

Selected results on estimating cosmological parameters from simulated weak lensing data with noise are presented. Numerical simulations of ray tracing through N-body simulations have been used to generate shear and convergence maps due to…

Astrophysics · Physics 2007-05-23 Bhuvnesh Jain , Uros Seljak , Simon White

Parallax measurements of pulsars allow for accurate measurements of the interstellar electron density and contribute to accurate tests of general relativity using binary systems. The Square Kilometre Array (SKA) will be an ideal instrument…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 R. Smits , S. J. Tingay , N. Wex , M. Kramer , B. Stappers

Full ray-tracing maps of gravitational lensing, constructed from N-Body simulations, represent a fundamental tool to interpret present and future weak lensing data. However the limitation of computational resources and storage capabilities…

The Red-Sequence Cluster Survey (RCS) is a 100 square degree galaxy cluster survey designed to provide a large sample of optically selected clusters of galaxies with redshifts 0.1<z<1.4. The survey data are also useful for a variety of…

Astrophysics · Physics 2007-05-23 Henk Hoekstra , Howard Yee , Mike Gladders

Cosmological simulations predict that galaxies are embedded into triaxial dark matter haloes, which appear approximately elliptical in projection. Weak gravitational lensing allows us to constrain these halo shapes and thereby test the…

We seek to understand the impact on shape estimators obtained from circular and elliptical shapelet models under two realistic conditions: (a) only a limited number of shapelet modes is available for the model, and (b) the intrinsic…

Instrumentation and Methods for Astrophysics · Physics 2014-07-24 P. Melchior , A. Boehnert , M. Lombardi , M. Bartelmann

We have analysed ~24 square degrees of R_C-band imaging data from the Red-Sequence Cluster Survey (RCS), and measured the excess correlations between galaxy ellipticities on scales ranging from 1 to 30 arcminutes. We have used data from two…

Weak gravitational lensing of distant galaxies by foreground structures has proven to be a powerful tool to study the mass distribution in the universe. The advent of panoramic cameras on 4m class telescope has led to a first generation of…

Astrophysics · Physics 2019-10-23 Henk Hoekstra

The Square Kilometre Array is going to become operational at the time when several new large optical, X-ray and Gamma-ray telescopes are expected to be working. The main drive for building the SKA is a significant improvement of sensitivity…

Astrophysics · Physics 2008-10-07 Dharam V. Lal , Andrei P. Lobanov

Weak gravitational lensing is an important tool to estimate the masses of galaxy clusters, as it allows us to directly access their projected surface mass density along the line-of-sight (LOS) in a manner largely independent of their…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-13 Constantin Payerne , Corentin Hanser , Calum Murray , Nathan Amouroux , Céline Combet

We discuss the ability of the SKA to observe QSO proper motions induced by long-wavelength gravitational radiation. We find that the SKA, configured for VLBI with multiple beams at high frequency (8 GHz), is sensitive to a dimensionless…

Astrophysics · Physics 2009-11-10 Andrew H. Jaffe

$ $Weak gravitational lensing is a powerful probe which is used to constrain the standard cosmological model and its extensions. With the enhanced statistical precision of current and upcoming surveys, high accuracy predictions for weak…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 Ting Tan , Dominik Zuercher , Janis Fluri , Alexandre Refregier , Federica Tarsitano , Tomasz Kacprzak

Radio observations of strongly lensed objects are valuable as cosmological probes. Lensed radio sources have proven difficult to identify in large part due to the limited depth and angular resolution of the previous generation of radio sky…

Astrophysics of Galaxies · Physics 2025-01-07 Michael N. Martinez , Yjan A. Gordon , Keith Bechtol , Gillian Cartwright , Peter S. Ferguson , Miranda Gorsuch

We describe the simulation data produced by a pilot programme to compute mock weak gravitational lensing maps for a range of currently popular cosmological models by ray tracing through high-resolution N-body simulations. The programme…

Astrophysics · Physics 2008-11-26 Martin White , Chris Vale

Given a foreground galaxy-density field or shear field, its cross-correlation with the shear field from a background population of source galaxies scales with the source redshift in a way that is specific to lensing. Such a source-scaling…

Astrophysics · Physics 2008-11-26 Jun Zhang , Lam Hui , Albert Stebbins

The current methods available to estimate gravitational shear from astronomical images of galaxies introduce systematic errors which can affect the accuracy of weak lensing cosmological constraints. We study the impact of KSB shape…

We study the prospects for measuring the dark matter distribution of voids with stacked weak lensing. We select voids from a large set of $N$-body simulations, and explore their lensing signals with the full ray-tracing simulations…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Yuichi Higuchi , Masamune Oguri , Takashi Hamana

The Euclid space telescope will observe ~10^5 strong galaxy-galaxy gravitational lens events in its wide field imaging survey over around half the sky, but identifying the gravitational lenses from their observed morphologies requires…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Stephen Serjeant

Weak lensing by large-scale structure allows a direct measure of the dark matter distribution. We have used parallel images taken with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope to measure weak lensing, or…