Publications by Rémy Elie Joseph

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

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

Uncovering a population of gravitational lens galaxies with magnified standard candle SN Zwicky

Johan Richard, Johannes Richard Cornelis Geerit Kruis, Rémy Elie Joseph, Cameron Alexander Campbell Lemon

Detecting gravitationally lensed supernovae is among the biggest challenges in astronomy. It involves a combination of two very rare phenomena: catching the transient signal of a stellar explosion in a distant galaxy and observing it through a nearly perfe ...

NATURE PORTFOLIO2023

SLITRONOMY: Towards a fully wavelet-based strong lensing inversion technique

Frédéric Courbin, Aymeric Alexandre Galan, Rémy Elie Joseph, Austin Chandler Peel

Strong gravitational lensing provides a wealth of astrophysical information on the baryonic and dark matter content of galaxies. It also serves as a valuable cosmological probe by allowing us to measure the Hubble constant independently of other methods. T ...

EDP SCIENCES S A2021

COSMOGRAIL: XIX. Time delays in 18 strongly lensed quasars from 15 years of optical monitoring star

Malte Tewes, Georges Meylan, Frédéric Courbin, Vivien François Bonvin, Martin Raoul Robert Millon, Aymeric Alexandre Galan, Eric Gérard Guy Paic, Rémy Elie Joseph, Olga Tihhonova, Hung-Hsu Chan, Cameron Alexander Campbell Lemon

We present the results of 15 years of monitoring lensed quasars, which was conducted by the COSMOGRAIL programme at the Leonhard Euler 1.2 m Swiss Telescope. The decade-long light curves of 23 lensed systems are presented for the first time. We complement ...

EDP SCIENCES S A2020

Sparse Lens Inversion Technique (SLIT): lens and source separability from linear inversion of the source reconstruction problem

Frédéric Courbin, Rémy Elie Joseph

Strong gravitational lensing offers a wealth of astrophysical information on the background source it affects, provided the lensed source can be reconstructed as if it was seen in the absence of lensing. In the present work, we illustrate how sparse optimi ...

EDP SCIENCES S A2019

Dark matter dynamics in Abell 3827: new data consistent with standard cold dark matter

Johan Richard, Frédéric Courbin, Richard Massey, Rémy Elie Joseph, David Richard Harvey, Mathilde Jauzac

2018

Sparse Linear Inversion for Strong Gravitational Lenses Reconstruction, Component Separation from Morphological Component Analysis with Multiple Discrimination Criteria

Rémy Elie Joseph

Strong gravitational is a natural phenomenon that produces distorted images of distant galaxies due to massive galaxies or clusters, called deflectors or lenses, lying along the line of sight. Due to the mass of the deflector, and as a result of general re ...

EPFL2018

A test for skewed distributions of dark matter, and a possible detection in galaxy cluster Abell 3827

Frédéric Courbin, Richard Massey, Rémy Elie Joseph, David Richard Harvey, Mathilde Jauzac

Simulations of self-interacting dark matter predict that dark matter should lag behind galaxies during a collision. If the interaction is mediated by a high-mass force carrier, the distribution of dark matter can also develop asymmetric dark matter tails. ...

Oxford Univ Press2017

Multi-band morpho-Spectral Component Analysis Deblending Tool (MuSCADeT): Deblending colourful objects

Frédéric Courbin, Rémy Elie Joseph

We introduce a new algorithm for colour separation and deblending of multi-band astronomical images called MuSCADeT which is based on Morpho-spectral Component Analysis of multi-band images. The MuSCADeT algorithm takes advantage of the sparsity of astrono ...

Edp Sciences S A2016

The PCA Lens-Finder: application to CFHTLS

Frédéric Courbin, Christoph Ernst René Schäfer, Jean-Paul Richard Kneib, Rémy Elie Joseph, Danuta Janina Paraficz

We present the results of a new search for galaxy-scale strong lensing systems in CFHTLS Wide. Our lens-finding technique involves a preselection of potential lens galaxies, applying simple cuts in size and magnitude. We then perform a Principal Component ...

Edp Sciences S A2016

A PCA-based automated finder for galaxy-scale strong lenses

Georges Meylan, Frédéric Courbin, Jean-Paul Richard Kneib, Rémy Elie Joseph

We present an algorithm using principal component analysis (PCA) to subtract galaxies from imaging data and also two algorithms to find strong, galaxy-scale gravitational lenses in the resulting residual image. The combined method is optimised to find full ...

EDP Sciences2014