scholarly journals Estimating the weak-lensing rotation signal in radio cosmic shear surveys

2017 ◽  
Vol 470 (3) ◽  
pp. 3131-3148 ◽  
Author(s):  
Daniel B. Thomas ◽  
Lee Whittaker ◽  
Stefano Camera ◽  
Michael L. Brown
Keyword(s):  
Weak Lensing ◽  
Cosmic Shear ◽  
Rotation Signal

scholarly journals KiDS+GAMA: Intrinsic alignment model constraints for current and future weak lensing cosmology

2019 ◽  
Vol 624 ◽  
pp. A30 ◽  
Author(s):  
Harry Johnston ◽  
Christos Georgiou ◽  
Benjamin Joachimi ◽  
Henk Hoekstra ◽  
Nora Elisa Chisari ◽  
...  
Keyword(s):  
Sloan Digital Sky Survey ◽  
Weak Lensing ◽  
Satellite Galaxy ◽  
Sky Survey ◽  
The Galaxy ◽  
Resolution Imaging ◽  
Cosmic Shear ◽  
Linear Alignment ◽  
Red Galaxies ◽  
Blue Galaxy

We directly constrain the non-linear alignment (NLA) model of intrinsic galaxy alignments, analysing the most representative and complete flux-limited sample of spectroscopic galaxies available for cosmic shear surveys. We measure the projected galaxy position-intrinsic shear correlations and the projected galaxy clustering signal using high-resolution imaging from the Kilo Degree Survey (KiDS) overlapping with the GAMA spectroscopic survey, and data from the Sloan Digital Sky Survey. Separating samples by colour, we make no significant detection of blue galaxy alignments, constraining the blue galaxy NLA amplitude AIAB = 0.21−0.36+0.37 to be consistent with zero. We make robust detections (∼9σ) for red galaxies, with AIAR = 3.18−0.46+0.47, corresponding to a net radial alignment with the galaxy density field, and we find no evidence for any scaling of alignments with galaxy luminosity. We provide informative priors for current and future weak lensing surveys, an improvement over de facto wide priors that allow for unrealistic levels of intrinsic alignment contamination. For a colour-split cosmic shear analysis of the final KiDS survey area, we forecast that our priors will improve the constraining power on S8 and the dark energy equation of state w0, by up to 62% and 51%, respectively. Our results indicate, however, that the modelling of red/blue-split galaxy alignments may be insufficient to describe samples with variable central/satellite galaxy fractions.

scholarly journals Very weak lensing in the CFHTLS wide: cosmology from cosmic shear in the linear regime

2007 ◽  
Vol 479 (1) ◽  
pp. 9-25 ◽  
Author(s):  
L. Fu ◽  
E. Semboloni ◽  
H. Hoekstra ◽  
M. Kilbinger ◽  
L. van Waerbeke ◽  
...  
Keyword(s):  
Weak Lensing ◽  
Linear Regime ◽  
Cosmic Shear

scholarly journals Detecting baryon acoustic oscillations in dark matter from kinematic weak lensing surveys

2019 ◽  
Vol 487 (1) ◽  
pp. 253-267
Author(s):  
Zhejie Ding ◽  
Hee-Jong Seo ◽  
Eric Huff ◽  
Shun Saito ◽  
Douglas Clowe
Keyword(s):  
Dark Matter ◽  
Task Force ◽  
Stage Iv ◽  
Weak Lensing ◽  
Acoustic Oscillations ◽  
Precision Level ◽  
Baryon Acoustic Oscillations ◽  
Cosmic Shear ◽  
Spatial Power Spectrum ◽  
Tomography Data

Abstract We investigate the feasibility of extracting baryon acoustic oscillations (BAO) from cosmic shear tomography. We particularly focus on the BAO scale precision that can be achieved by future spectroscopy-based, kinematic weak lensing (KWL) surveys in comparison to the traditional photometry-based weak lensing surveys. We simulate cosmic shear tomography data of such surveys with a few simple assumptions to focus on the BAO information, extract the spatial power spectrum, and constrain the recovered BAO feature. Due to the small shape noise and the shape of the lensing kernel, we find that a Dark Energy Task Force Stage IV version of such KWL survey can detect the BAO feature in dark matter by 3σ and measure the BAO scale at the precision level of 4 per cent, while it will be difficult to detect the feature in photometry-based weak lensing surveys. With a more optimistic assumption, a KWL-Stage IV could achieve a ${\sim } 2{{\ \rm per\ cent}}$ BAO scale measurement with 4.9σ confidence. A built-in spectroscopic galaxy survey within such KWL survey will allow cross-correlation between galaxies and cosmic shear, which will tighten the constraint beyond the lower limit we present in this paper and therefore possibly allow a detection of the BAO scale bias between galaxies and dark matter.

scholarly journals Prospects for weak lensing/cosmic shear with VLTs

2003 ◽  
Author(s):  
Yannick Mellier ◽  
L. van Waerbeke ◽  
Etienne Bertin ◽  
I. Tereno ◽  
P. Schneider ◽  
...  
Keyword(s):  
Weak Lensing ◽  
Cosmic Shear

scholarly journals Mapping the Dark Matter Using Weak Lensing

2005 ◽  
Vol 216 ◽  
pp. 140-151
Author(s):  
Henk Hoekstra
Keyword(s):  
Dark Matter ◽  
Galaxy Formation ◽  
Gravitational Lensing ◽  
Cosmological Parameters ◽  
Weak Lensing ◽  
Major Step ◽  
Redshift Distribution ◽  
Panoramic Cameras ◽  
The Galaxy ◽  
Cosmic Shear

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 4-m class telescopes has led to a first generation of surveys that already compete with large redshift surveys in terms of the accuracy with which cosmological parameters can be determined. The next surveys, which already have started taking data, will provide another major step forward. At the current level, systematics appear under control, and it is expected that weak lensing will develop into a key tool in the era of precision cosmology, provided we improve our knowledge of the non-linear matter power spectrum and the source redshift distribution. In this review we will briefly describe the principles of weak lensing and discuss the results of recent cosmic shear surveys. We show how the combination of weak lensing and cosmic microwave background measurements can provide tight constraints on cosmological parameters. We also demonstrate the usefulness of weak lensing in studies of the relation between the galaxy distribution and the underlying dark matter distribution (“galaxy biasing”), which can provide important constraints on models of galaxy formation. Finally, we discuss new and upcoming large cosmic shear surveys.

scholarly journals Full-sky Ray-tracing Simulation of Weak Lensing Using ELUCID Simulations: Exploring Galaxy Intrinsic Alignment and Cosmic Shear Correlations

2018 ◽  
Vol 853 (1) ◽  
pp. 25 ◽  
Author(s):  
Chengliang Wei ◽  
Guoliang Li ◽  
Xi Kang ◽  
Yu Luo ◽  
Qianli Xia ◽  
...  
Keyword(s):  
Ray Tracing ◽  
Weak Lensing ◽  
Cosmic Shear ◽  
Ray Tracing Simulation

scholarly journals Radio–optical galaxy shape and shear correlations in the COSMOS field using 3 GHz VLA observations

2019 ◽  
Vol 488 (4) ◽  
pp. 5420-5436 ◽  
Author(s):  
Tom Hillier ◽  
Michael L Brown ◽  
Ian Harrison ◽  
Lee Whittaker
Keyword(s):  
Hubble Space Telescope ◽  
Pearson Correlation ◽  
Power Spectra ◽  
Optical Observations ◽  
Weak Lensing ◽  
Very Large Array ◽  
Cosmic Shear ◽  
Correlation Statistics ◽  
Insight Into ◽  
Source Number

Abstract We present a weak-lensing analysis of the 3 GHz Very Large Array radio survey of the COSMOS field, which we correlate with overlapping Hubble Space Telescope-Advanced Camera for Survey optical observations using both intrinsic galaxy shape and cosmic shear correlation statistics. After cross-matching sources between the two catalogues, we measure the correlations of galaxy position angles and find a Pearson correlation coefficient of 0.14 ± 0.03. This is a marked improvement from previous studies which found very weak, or non-existent correlations, and gives insight into the emission processes of radio and optical galaxies. We also extract power spectra of averaged galaxy ellipticities (the primary observable for cosmic shear) from the two catalogues, and produce optical–optical, radio–optical, and radio–radio spectra. The optical–optical autopower spectrum was measured to a detection significance of 9.80σ and is consistent with previous observations of the same field. For radio spectra (which we do not calibrate, given the unknown nature of their systematics), although we do not detect significant radio–optical (1.50σ) or radio–radio (1.45σ) E-mode power spectra, we do find the E-mode spectra to be more consistent with the shear signal expected from previous studies than with a null signal, and vice versa for B-mode and EB cross-correlation spectra. Our results give promise that future radio weak-lensing surveys with larger source number densities over larger areas will have the capability to measure significant weak-lensing signals.

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