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Related papers: Cosmic Shear with the VLT

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The <V/Vmax> of the cosmological X-ray flashes detected by WFC/BeppoSAX is calculated theoretically in a simple jet model. The total emission energy from the jet is assumed to be constant. We find that if the jet opening half-angle is…

Astrophysics · Physics 2009-11-10 Ryo Yamazaki , Kunihito Ioka , Takashi Nakamura

Standard cosmological weak lensing analyses using cosmic shear are inevitably sensitive to small-scale, non-linear clustering from low-redshift structures. The need to adequately model the clustering of matter on this non-linear regime,…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-25 Giulia Piccirilli , Matteo Zennaro , Carlos García-García , David Alonso

In this paper we discuss the commonly-used limiting cases, or approximations, for two-point cosmic shear statistics. We discuss the most prominent assumptions in this statistic: the flat-sky (small angle limit), the Limber (Bessel-to-delta…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-31 Thomas D. Kitching , Justin Alsing , Alan F. Heavens , Raul Jimenez , Jason D. McEwen , Licia Verde

The Cosmological Principle is a cornerstone of the standard model of cosmology and shapes how we view the Universe and our place within it. It is imperative, then, to devise multiple observational tests which can identify and quantify…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-13 James Adam , Roy Maartens , Julien Larena , Chris Clarkson

We examine the spatial extent of the narrow-line regions (NLRs) of a sample of 30 luminous obscured quasars at $0.4 < z < 0.7$ observed with spatially resolved Gemini-N GMOS long-slit spectroscopy. Using the [OIII]$\lambda5007$ emission…

Astrophysics of Galaxies · Physics 2015-06-19 Kevin N. Hainline , Ryan C. Hickox , Jenny E. Greene , Adam D. Myers , Nadia L. Zakamska , Guilin Liu , Xin Liu

Cosmic shear is one of the most powerful probes of Dark Energy, targeted by several current and future galaxy surveys. Lensing shear, however, is only sampled at the positions of galaxies with measured shapes in the catalog, making its…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-31 Andrina Nicola , Carlos García-García , David Alonso , Jo Dunkley , Pedro G. Ferreira , Anže Slosar , David N. Spergel

In this paper we report on the observation of the anisotropy of cosmic ray arrival direction at different angular scales with ARGO-YBJ. Evidence of new few-degree excesses throughout the sky region 195$^{\circ}\leq$ R.A. $\leq$…

High Energy Astrophysical Phenomena · Physics 2019-08-14 G. DI SCIASCIO

Future lensing surveys will be nearly full-sky and reach an unprecedented depth, probing scales closer and closer to the Hubble radius. This motivates the study of the cosmic shear beyond the small-angle approximation and including general…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-09 Francis Bernardeau , Camille Bonvin , Nicolas Van de Rijt , Filippo Vernizzi

Cosmic flexion, like cosmic shear, is a correlation function whose signal originates from the large-scale structure of the universe. Building on the observational success of cosmic shear, along with the unprecedented quality of large-scale…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-01 Evan J. Arena , David M. Goldberg , David J. Bacon

We derive constraints on dark matter (DM) annihilation cross section and decay lifetime from cross-correlation analyses of the data from Fermi-LAT and weak lensing surveys that cover a wide area of $\sim660$ squared degrees in total. We…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-29 Masato Shirasaki , Oscar Macias , Shunsaku Horiuchi , Satoshi Shirai , Naoki Yoshida

We present a tomographic cosmological weak lensing analysis of the HST COSMOS Survey. Applying our lensing-optimized data reduction, principal component interpolation for the ACS PSF, and improved modelling of charge-transfer inefficiency,…

We present a semi-analytic model for the shear two-point correlation function of a cosmic shear survey with non-uniform depth. Ground-based surveys are subject to depth variations that primarily arise through varying atmospheric conditions.…

We explore the feasibility of using the atmosphere of Jupiter to detect Ultra-High-Energy Cosmic Rays (UHECR's). The large surface area of Jupiter allows us to probe cosmic rays of higher energies than previously accessible. Cosmic ray…

Earth and Planetary Astrophysics · Physics 2015-06-19 Paul B. Rimmer , Craig R. Stark , Christiane Helling

Weak lensing observations have the potential to be even more powerful than cosmic microwave background (CMB) observations in constraining cosmological parameters. However, the practical limits to weak lensing observations are not known.…

Astrophysics · Physics 2009-11-13 D. Wittman

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

We present the most distant detection of cosmic voids ($z \sim 2.3$) and the first detection of three-dimensional voids in the Lyman-$\alpha$ forest. We used a 3D tomographic map of the absorption with effective comoving spatial resolution…

The cosmological interpretation of weak lensing by large-scale structures requires knowledge of the redshift distribution of the source galaxies. Current lensing surveys are often calibrated using external redshift samples which span a…

Astrophysics · Physics 2008-11-26 Ludovic Van Waerbeke , Martin White , Henk Hoekstra , Catherine Heymans

We present the results of weak gravitational lensing statistics in four different cosmological $N$-body simulations. The data has been generated using an algorithm for the three-dimensional shear, which makes use of a variable softening…

Astrophysics · Physics 2009-10-31 Andrew J. Barber , Peter A. Thomas , H. M. P. Couchman , C. J. Fluke

We discuss the present status and future prospects for cosmic shear observations and their cosmological constraints. We review the evidences supporting the cosmological origin of the measured signal, and discuss the possible problems coming…

Astrophysics · Physics 2007-05-23 L. Van Waerbeke , Y. Mellier , I. Tereno