Concept

Microlentille gravitationnelle

Publications associées (175)

Systematic or signal? How dark matter misalignments can bias strong lensing models of galaxy clusters

Jean-Paul Richard Kneib, David Richard Harvey, Mathilde Jauzac

We explore how assuming that mass traces light in strong gravitational lensing models can lead to systematic errors in the predicted position of multiple images. Using a model based on the galaxy cluster MACS J0416 (z = 0.397) from the Hubble Frontier Fiel ...

Oxford Univ Press2016

Evaluating the effect of stellar multiplicity on the point spread function of space-based weak lensing surveys

Frédéric Courbin, Georges Meylan, Thibault Adrien Kuntzer

The next generation of space-based telescopes used for weak lensing surveys will require exquisite point spread function (PSF) determination. Previously negligible effects may become important in the reconstruction of the PSF, in part because of the improv ...

Edp Sciences S A2016

Galaxy Alignments: An Overview

Anaïs Marie Rassat

The alignments between galaxies, their underlying matter structures, and the cosmic web constitute vital ingredients for a comprehensive understanding of gravity, the nature of matter, and structure formation in the Universe. We provide an overview on the ...

Springer2015

Galaxy Alignments: Observations and Impact on Cosmology

Anaïs Marie Rassat

Galaxy shapes are not randomly oriented, rather they are statistically aligned in a way that can depend on formation environment, history and galaxy type. Studying the alignment of galaxies can therefore deliver important information about the physics of g ...

Springer2015

Discovery of two gravitationally lensed quasars in the Dark Energy Survey

Yi Zhang, Eduardo Sanchez, Frédéric Courbin, Georges Meylan, Adriano Agnello

We present spectroscopic confirmation of two new gravitationally lensed quasars, discovered in the Dark Energy Survey (DES) and Wide-field Infrared Survey Explorer (WISE) based on their multiband photometry and extended morphology in DES images. Images of ...

Oxford Univ Press2015

The Weak Lensing Signal And The Clustering Of Boss Galaxies. I. Measurements

Jean-Paul Richard Kneib

A joint analysis of the clustering of galaxies and their weak gravitational lensing signal is well-suited to simultaneously constrain the galaxy-halo connection as well as the cosmological parameters by breaking the degeneracy between galaxy bias and the a ...

American Astronomical Society2015

Galaxy Alignments: Theory, Modelling & Simulations

Anaïs Marie Rassat

The shapes of galaxies are not randomly oriented on the sky. During the galaxy formation and evolution process, environment has a strong influence, as tidal gravitational fields in the large-scale structure tend to align nearby galaxies. Additionally, even ...

Springer2015

A Consistent Picture Emerges: A Compact X-Ray Continuum Emission Region In The Gravitationally Lensed Quasar Sdss J0924+0219

Frédéric Courbin, Georges Meylan, Malte Tewes

We analyze the optical, UV, and X-ray microlensing variability of the lensed quasar SDSS J0924+ 0219 using six epochs of Chandra data in two energy bands (spanning 0.4-8.0 keV, or 1-20 keV in the quasar rest frame), 10 epochs of F275W (rest-frame 1089 angs ...

American Astronomical Society2015

Hopfield neural network deconvolution for weak lensing measurement

Frédéric Courbin, Georges Meylan, Malte Tewes, Guldariya Nurbaeva

Weak gravitational lensing has the potential to place tight constraints on the equation of the state of dark energy. However, this will only be possible if shear measurement methods can reach the required level of accuracy. We present a new method for meas ...

EDP Sciences2015

Hubble Frontier Fields: a high-precision strong-lensing analysis of the massive galaxy cluster Abell 2744 using similar to 180 multiple images

Jean-Paul Richard Kneib, Benjamin Yvan Alexandre Clement, Mathilde Jauzac, Hakim Atek, Markus Rexroth, Richard Massey, Johan Richard

We present a high-precision mass model of galaxy cluster Abell 2744, based on a strong gravitational-lensing analysis of the Hubble Space Telescope Frontier Fields (HFF) imaging data, which now include both Advanced Camera for Surveys and Wide Field Camera ...

Oxford University Press2015

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