Concept

Lentille gravitationnelle faible

Publications associées (336)

KiDS and Euclid: Cosmological implications of a pseudo angular power spectrum analysis of KiDS-1000 cosmic shear tomography

Georges Meylan, Jean-Luc Starck, Huanyuan Shan, Yi Wang, Richard Massey

We present a tomographic weak lensing analysis of the Kilo Degree Survey Data Release 4 (KiDS-1000), using a new pseudo angular power spectrum estimator (pseudo-C-l) under development for the ESA Euclid mission. Over 21 million galaxies with shape informat ...

EDP SCIENCES S A2022

Next generation modeling techniques for strong gravitational lensing and measuring the Hubble constant

Aymeric Alexandre Galan

For many years, observations of the Universe suggest a series problems with our theoretical models, particularly its dark energy and dark matter components. Fortunately, the Universe also provides us with a tool to solve these problems, called strong gravi ...

EPFL2022

Probing gravity with the DES-CMASS sample and BOSS spectroscopy

Eduardo Sanchez, Jonathan Andrew Blazek

The DES-CMASS sample (DMASS) is designed to optimally combine the weak lensing measurements from the Dark Energy Survey (DES) and redshift-space distortions (RSD) probed by the CMASS galaxy sample from the Baryonic Oscillation Spectroscopic Survey. In this ...

2022

Survey of Gravitationally lensed objects in HSC Imaging (SuGOHI). VIII. New galaxy-scale lenses from the HSC SSP

Hung-Hsu Chan

We conduct a search for galaxy-scale strong gravitational lens systems in Data Release 4 of the Hyper Suprime-Cam Subaru Strategic Program (HSC SSP), consisting of data taken up to the S21A semester. We select 103191 luminous red galaxies from the Baryon O ...

OXFORD UNIV PRESS2022

Teaching machines how to find strongly lensed galaxies in cosmological sky surveys.

Elodie Marie Charlène Savary

Analyzing gravitationally lensed objects enables a wide range of physical and cosmological applications, such as probing the dark matter content in galaxies and clusters or measuring the Universe's expansion rate.The precision of these applications can be ...

EPFL2022

Strong lensing in UNIONS: Toward a pipeline from discovery to modeling

Frédéric Courbin, Benjamin Yvan Alexandre Clement, Cameron Alexander Campbell Lemon, Hung-Hsu Chan, Karina Alexandra Rojas Olate, Georgios Vernardos, Elodie Marie Charlène Savary

We present a search for galaxy-scale strong gravitational lenses in the initial 2500 square degrees of the Canada-France Imaging Survey (CFIS). We designed a convolutional neural network (CNN) committee that we applied to a selection of 2 344 002 r-band im ...

EDP SCIENCES S A2022

Constraining the baryonic feedback with cosmic shear using the DES Year-3 small-scale measurements

Yi Zhang, Eduardo Sanchez, Jonathan Andrew Blazek, Binglun Yin

We use the small scales of the Dark Energy Survey (DES) Year-3 cosmic shear measurements, which are excluded from the DES Year-3 cosmological analysis, to constrain the baryonic feedback. To model the baryonic feedback, we adopt a baryonic correction model ...

Oxford2022

The very knotty lenser: Exploring the role of regularization in source and potential reconstructions using Gaussian process regression

Georgios Vernardos

Reconstructing lens potentials and lensed sources can easily become an underconstrained problem, even when the degrees of freedom are low, due to degeneracies, particularly when potential perturbations superimposed on a smooth lens are included. Regulariza ...

OXFORD UNIV PRESS2022

Using wavelets to capture deviations from smoothness in galaxy-scale strong lenses

Frédéric Courbin, Aymeric Alexandre Galan, Austin Chandler Peel, Georgios Vernardos

Modeling the mass distribution of galaxy-scale strong gravitational lenses is a task of increasing difficulty. The high-resolution and depth of imaging data now available render simple analytical forms ineffective at capturing lens structures spanning a la ...

EDP SCIENCES S A2022

Dark matter in galaxy clusters: Parametric strong-lensing approach

Benjamin Emmanuel Nicolas Beauchesne

We present a parametric strong-lensing analysis of three massive galaxy clusters for which Hubble Space Telescope imaging is available, as well as spectroscopy of multiply imaged systems and galaxy cluster members. Our aim is to probe the inner shape of da ...

EDP SCIENCES S A2022

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