Publications by Benjamin Yvan Alexandre Clement

Euclid: A complete Einstein ring in NGC 6505

Frédéric Courbin, Georges Meylan, Benjamin Yvan Alexandre Clement

We report the discovery of a complete Einstein ring around the elliptical galaxy NGC 6505, at z = 0.042. This is the first strong gravitational lens discovered in Euclid and the first in an NGC object from any survey. The combination of the low redshift of ...

2025

Euclid: Searches for strong gravitational lenses using convolutional neural nets in Early Release Observations of the Perseus field

Georges Meylan, Benjamin Yvan Alexandre Clement

The Euclid Wide Survey (EWS) is predicted to find approximately 170 000 galaxy-galaxy strong lenses from its lifetime observation of 14 000 deg2 of the sky. Detecting this many lenses by visual inspection with professional astronomers and citizen scientist ...

2025

Euclid preparation XLVIII. The pre-launch Science Ground Segment simulation framework

Frédéric Courbin, Georges Meylan, Benjamin Yvan Alexandre Clement

Context. The European Space Agency’s Euclid mission is one of a raft of forthcoming large-scale cosmology surveys that will map the large-scale structure in the Universe with unprecedented precision. The mission will collect a vast amount of data that will ...

2024

Euclid preparation XXXIII. Characterization of convolutional neural networks for the identification of galaxy-galaxy strong-lensing events

Frédéric Courbin, Georges Meylan, Benjamin Yvan Alexandre Clement, Georgios Vernardos

Forthcoming imaging surveys will increase the number of known galaxy-scale strong lenses by several orders of magnitude. For this to happen, images of billions of galaxies will have to be inspected to identify potential candidates. In this context, deep-le ...

Edp Sciences S A2024

The impact of human expert visual inspection on the discovery of strong gravitational lenses

Frédéric Courbin, Benjamin Yvan Alexandre Clement, Eric Gérard Guy Paic, Hung-Hsu Chan, Martin Raoul Robert Millon, Karina Alexandra Rojas Olate, Rémy Elie Joseph, Elodie Marie Charlène Savary, Yue Pan

We investigate the ability of human 'expert' classifiers to identify strong gravitational lens candidates in Dark Energy Survey like imaging. We recruited a total of 55 people that completed more than 25 per cent of the project. During the classification t ...

OXFORD UNIV PRESS2023

A new step forward in realistic cluster lens mass modelling: analysis of Hubble Frontier Field Cluster Abell S1063 from joint lensing, X-ray, and galaxy kinematics data

Jean-Paul Richard Kneib, Benjamin Yvan Alexandre Clement, Benjamin Emmanuel Nicolas Beauchesne, Mathilde Jauzac, Johan Richard

We present a new method to simultaneously and self-consistently model the mass distribution of galaxy clusters that combines constraints from strong lensing features, X-ray emission, and galaxy kinematics measurements. We are able to successfully decompose ...

Oxford Univ Press2023

Probing the faint-end luminosity function of Lyman-alpha emitters at 3 < z < 7 behind 17 MUSE lensing clusters

Benjamin Yvan Alexandre Clement, Johan Richard

Context. This paper presents a study of the galaxy Lyman-alpha luminosity function (LF) using a large sample of 17 lensing clusters observed by the Multi Unit Spectroscopic Explorer (MUSE) at the ESO Very Large Telescope (VLT). The magnification resulting ...

Edp Sciences S A2023

Precision Modeling of JWST's First Cluster Lens SMACS J0723.3-7327*

Jean-Paul Richard Kneib, Benjamin Yvan Alexandre Clement, Benjamin Emmanuel Nicolas Beauchesne

Exploiting the fundamentally achromatic nature of gravitational lensing, we present a lens model for the massive galaxy cluster SMACS J0723.3-7323 (SMACS J0723; z = 0.388) that significantly improves upon earlier work. Building on strong-lensing constraint ...

IOP Publishing Ltd2023

Discovery of strongly lensed quasars in the Ultraviolet Near Infrared Optical Northern Survey (UNIONS)

Benjamin Yvan Alexandre Clement, Eric Gérard Guy Paic, Hung-Hsu Chan, Martin Raoul Robert Millon, Karina Alexandra Rojas Olate, Cameron Alexander Campbell Lemon, Georgios Vernardos, Elodie Marie Charlène Savary

We report the discovery of five new doubly imaged lensed quasars from the first 2500 square degrees of the ongoing Canada-France Imaging Survey (CFIS), which is a component of the Ultraviolet Near Infrared Optical Northern Survey. The systems are preselect ...

EDP SCIENCES S A2022

Search of strong lens systems in the Dark Energy Survey using convolutional neural networks

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

We present our search for strong lens, galaxy-scale systems in the first data release of the Dark Energy Survey (DES), based on a color-selected parent sample of 18 745 029 luminous red galaxies (LRGs). We used a convolutional neural network (CNN) to grade ...

EDP SCIENCES S A2022