Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Concept

Anneau d'Einstein

Publications associées (31)

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

Simulating time-varying strong lenses

Georgios Vernardos

We present a self-consistent and versatile forward modelling software package that can produce time series and pixel-level simulations of time-varying strongly lensed systems. The time dimension, which needs to take into account different physical mechanis ...

OXFORD UNIV PRESS2022

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

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

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

Frédéric Courbin, Hung-Hsu Chan, Cameron Alexander Campbell Lemon, Georgios Vernardos, Benjamin Yvan Alexandre Clement, Karina Alexandra Rojas Olate, 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 quasar structure using high-frequency microlensing variations and continuum reverberation

Frédéric Courbin, Vivien François Bonvin, Martin Raoul Robert Millon, Hung-Hsu Chan, Georgios Vernardos, Eric Gérard Guy Paic

Gravitational microlensing is a powerful tool for probing the inner structure of strongly lensed quasars and for constraining parameters of the stellar mass function of lens galaxies. This is achieved by analysing microlensing light curves between the mult ...

EDP SCIENCES S A2022

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

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

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

Time-delay Cosmography with Strongly Lensed Quasars

Martin Raoul Robert Millon

The LCDM model has emerged as the concordance model of cosmology for its ability to explain a variety of observations, ranging from the anisotropies of the Cosmic Microwave Background (CMB) to the accelerated expansion of the Universe. However, with the ev ...

EPFL2021

Tightening weak lensing constraints on the ellipticity of galaxy-scale dark matter haloes

Anand Stéphane Raichoor

Cosmological simulations predict that galaxies are embedded into triaxial dark matter haloes, which appear approximately elliptical in projection. Weak gravitational lensing allows us to constrain these halo shapes and thereby test the nature of dark matte ...

EDP SCIENCES S A2021

Measuring accretion disk sizes of lensed quasars with microlensing time delay in multi-band light curves

Frédéric Courbin, Hung-Hsu Chan, Vivien François Bonvin, Martin Raoul Robert Millon, Karina Alexandra Rojas Olate

Time-delay cosmography in strongly lensed quasars offers an independent way of measuring the Hubble constant, H-0. However, it has been proposed that the combination of microlensing and source-size effects, also known as microlensing time delay, can potent ...

EDP SCIENCES S A2021

The AGORA High-resolution Galaxy Simulations Comparison Project. III. Cosmological Zoom-in Simulation of a Milky Way-mass Halo

Yves Revaz, Loïc Hausammann

We present a suite of high-resolution cosmological zoom-in simulations to z = 4 of a 10(12) M (circle dot) halo at z = 0, obtained using seven contemporary astrophysical simulation codes (Art-I, Enzo, Ramses, Changa, Gadget-3, Gear, and Gizmo) widely used ...

IOP PUBLISHING LTD2021