Publication
Searching for Strong Gravitational Lenses
Publications associées (72)
Strong gravitational lensing's 'external shear' is not shear
David Richard Harvey, Mathilde Jauzac, Richard Massey
The distribution of mass in galaxy-scale strong gravitational lenses is often modelled as an elliptical power-law plus 'external shear', which notionally accounts for neighbouring galaxies and cosmic shear along our line of sight. A small amount of externa ...
Oxford Univ Press2024Strong and micro lensing in distant quasars
Most large galaxies contain Super Massive Black Holes at their centers, drawing matter nearby to form swirling accretion disks emitting electromagnetic radiation. These are Active Galactic Nuclei. The brightest quasars are the most luminous Universe object ...
EPFL2023Gravitationally lensed quasars in Gaia - IV. 150 new lenses, quasar pairs, and projected quasars
Frédéric Courbin, Aymeric Alexandre Galan, Cameron Alexander Campbell Lemon, Adriano Agnello
We report the spectroscopic follow-up of 175 lensed quasar candidates selected using Gaia Data Release 2 observations following Paper III of this series. Systems include 86 confirmed lensed quasars and a further 17 likely lensed quasars based on imaging an ...
OXFORD UNIV PRESS2023The impact of human expert visual inspection on the discovery of strong gravitational lenses
Frédéric Courbin, Benjamin Yvan Alexandre Clement, Martin Raoul Robert Millon, Eric Gérard Guy Paic, Hung-Hsu Chan, 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 PRESS2023LensWatch. I. Resolved HST Observations and Constraints on the Strongly Lensed Type Ia Supernova 2022qmx ("SN Zwicky")
Frédéric Courbin, Adriano Agnello
Supernovae (SNe) that have been multiply imaged by gravitational lensing are rare and powerful probes for cosmology. Each detection is an opportunity to develop the critical tools and methodologies needed as the sample of lensed SNe increases by orders of ...
IOP Publishing Ltd2023Repair! Reclaiming Berlin’s Workers’ Housing through Collaborative Transformation
The phase of economic and humanitarian emergencies after the Great War functioned as a laboratory for architects to develop quick, rational responses. But socialist visions became stuck in privatization, and values of a bygone society were maintained by pr ...
2023SEAGLE III: Towards resolving the mismatch in the dark-matter fraction in early-type galaxies between simulations and observations
Georgios Vernardos, Matthieu Schaller
The central dark-matter fraction of galaxies is sensitive to feedback processes during galaxy formation. Strong gravitational lensing has been effective in the precise measurement of the dark-matter fraction inside massive early-type galaxies. Here, we com ...
OXFORD UNIV PRESS2022Strong 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 A2022Next generation modeling techniques for strong gravitational lensing and measuring the Hubble constant
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 ...
EPFL2022Teaching machines how to find strongly lensed galaxies in cosmological sky surveys.
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