Publications de Vivien François Bonvin

Tdcosmo Xvii. New Time Delays in 22 Lensed Quasars From Optical Monitoring with the Eso-vst 2.6m and Mpg 2.2m Telescopes

Frédéric Courbin, Vivien François Bonvin, Aymeric Alexandre Galan, Eric Gérard Guy Paic, Cameron Alexander Campbell Lemon

We present new time delays, the main ingredient of time delay cosmography, for 22 lensed quasars resulting from high-cadence r-band monitoring on the 2.6 m ESO VLT Survey Telescope and Max-Planck-Gesellschaft 2.2 m telescope. Each lensed quasar was typical ...

EDP SCIENCES S A2025

VELOcities of CEpheids (VELOCE): I. High-precision radial velocities of Cepheids

Vivien François Bonvin, Shreeya Sushil Shetye, Saniya Khan, Henryka Ewa Netzel

We present the first data release of VELOcities of CEpheids (VELOCE), dedicated to measuring the high-precision radial velocities (RVs) of Galactic classical Cepheids (henceforth, Cepheids). The first data release (VELOCE DR1) comprises 18 225 RV measureme ...

2024

Constraints on the Hubble constant from supernova Refsdal's reappearance

Vivien François Bonvin, Martin Raoul Robert Millon, Mathilde Jauzac, Anja Von der Linden

The gravitationally lensed supernova Refsdal appeared in multiple images produced through gravitational lensing by a massive foreground galaxy cluster. After the supernova appeared in 2014, lens models of the galaxy cluster predicted that an additional ima ...

American Association for the Advancement of Science2023

The Magnificent Five Images of Supernova Refsdal: Time Delay and Magnification Measurements

Vivien François Bonvin, Martin Raoul Robert Millon, Mathilde Jauzac, Anja Von der Linden

In late 2014, four images of Supernova (SN) "Refsdal," the first known example of a strongly lensed SN with multiple resolved images, were detected in the MACS J1149 galaxy-cluster field. Following the images' discovery, the SN was predicted to reappear wi ...

IOP Publishing Ltd2023

HOLISMOKES VII. Time-delay measurement of strongly lensed Type Ia supernovae using machine learning

Vivien François Bonvin, Hung-Hsu Chan

The Hubble constant (H-0) is one of the fundamental parameters in cosmology, but there is a heated debate around the > 4 sigma tension between the local Cepheid distance ladder and the early Universe measurements. Strongly lensed Type Ia supernovae (LSNe I ...

EDP SCIENCES S A2022

Constraining quasar structure using high-frequency microlensing variations and continuum reverberation

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

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

Time delay lens modelling challenge

Frédéric Courbin, Vivien François Bonvin, Martin Raoul Robert Millon, Aymeric Alexandre Galan, Di Xu

In recent years, breakthroughs in methods and data have enabled gravitational time delays to emerge as a very powerful tool to measure the Hubble constant H-0. However, published state-of-the-art analyses require of order 1 yr of expert investigator time a ...

OXFORD UNIV PRESS2021

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

Frédéric Courbin, Vivien François Bonvin, Martin Raoul Robert Millon, Hung-Hsu Chan, 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

H0LiCOW XII. Lens mass model of WFI2033-4723 and blind measurement of its time-delay distance and H-0

Frédéric Courbin, Vivien François Bonvin, Hung-Hsu Chan

We present the lens mass model of the quadruply-imaged gravitationally lensed quasar WFI2033 - 4723, and perform a blind cosmographical analysis based on this system. Our analysis combines (1) time-delay measurements from 14 yr of data obtained by the COSm ...

OXFORD UNIV PRESS2020

TDCOSMO II. Six new time delays in lensed quasars from high-cadence monitoring at the MPIA 2.2m telescope

Frédéric Courbin, Sun Hee Kim, Vivien François Bonvin, Martin Raoul Robert Millon, Eric Gérard Guy Paic, Hung-Hsu Chan, Karina Alexandra Rojas Olate, Cameron Alexander Campbell Lemon, Adriano Agnello

We present six new time-delay measurements obtained from Rc-band monitoring data acquired at the Max Planck Institute for Astrophysics (MPIA) 2.2m telescope at La Silla observatory between October 2016 and February 2020. The lensed quasars HE0047 1756, WG0 ...

EDP SCIENCES S A2020

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

HOLISMOKES: I. Highly Optimised Lensing Investigations of Supernovae, Microlensing Objects, and Kinematics of Ellipticals and Spirals

Frédéric Courbin, Vivien François Bonvin

We present the HOLISMOKES programme on strong gravitational lensing of supernovae (SNe) as a probe of SN physics and cosmology. We investigate the effects of microlensing on early-phase SN Ia spectra using four different SN explosion models. We find that d ...

EDP SCIENCES S A2020

H0LiCOW-XI. A weak lensing measurement of the external convergence in the field of the lensed quasar B1608+656 using HST and Subaru deep imaging

Georges Meylan, Frédéric Courbin, Vivien François Bonvin, David Richard Harvey, Olga Tihhonova, Austin Chandler Peel

We investigate the environment and line of sight (LoS) of the H0LiCOW (H-0 Lenses in COSMOGRAIL's Wellspring) lens B1608+656 using Subaru Suprime-Cam and the Hubble Space Telescope (HST) to perform a weak lensing analysis. We compare three different method ...

OXFORD UNIV PRESS2020

STRIDES: a 3.9 per cent measurement of the Hubble constant from the strong lens system DES J0408-5354

Georges Meylan, Frédéric Courbin, Vivien François Bonvin, Martin Raoul Robert Millon, Aymeric Alexandre Galan, Cameron Alexander Campbell Lemon

We present a blind time-delay cosmographic analysis for the lens system DES J0408-5354. This system is extraordinary for the presence of two sets of multiple images at different redshifts, which provide the opportunity to obtain more information at the cos ...

OXFORD UNIV PRESS2020

H0LiCOW-XIII. A 2.4 per cent measurement of H-0 from lensed quasars: 5.3 sigma tension between early- and late-Universe probes

Georges Meylan, Frédéric Courbin, Vivien François Bonvin, Martin Raoul Robert Millon, Olga Tihhonova, Hung-Hsu Chan, Adriano Agnello

We present a measurement of the Hubble constant (H-0) and other cosmological parameters from a joint analysis of six gravitationally lensed quasars with measured time delays. All lenses except the first are analysed blindly with respect to the cosmological ...

OXFORD UNIV PRESS2020

A Microlensing Accretion Disk Size Measurement in the Lensed Quasar WFI 2026-4536

Frédéric Courbin, Vivien François Bonvin, Martin Raoul Robert Millon

We use 13 seasons of R-band photometry from the 1.2 m Leonard Euler Swiss Telescope at La Silla to examine microlensing variability in the quadruply imaged lensed quasar WFI 2026-4536. The lightcurves exhibit similar to 0.2 mag of uncorrelated variability ...

IOP PUBLISHING LTD2020

Strongly lensed SNe Ia in the era of LSST: observing cadence for lens discoveries and time-delay measurements

Frédéric Courbin, Vivien François Bonvin, Hung-Hsu Chan

The upcoming Large Synoptic Survey Telescope (LSST) will detect many strongly lensed Type Ia supernovae (LSNe Ia) for time-delay cosmography. This will provide an independent and direct way for measuring the Hubble constant H0, which is necessary to addres ...

2019

COSMOGRAIL XVIII. time delays of the quadruply lensed quasar WFI2033-4723

Malte Tewes, Georges Meylan, Frédéric Courbin, Sun Hee Kim, Vivien François Bonvin, Martin Raoul Robert Millon, Hung-Hsu Chan, Karina Alexandra Rojas Olate

We present new measurements of the time delays of WFI2033-4723. The data sets used in this work include 14 years of data taken at the 1.2 m Leonhard Euler Swiss telescope, 13 years of data from the SMARTS 1.3 m telescope at Las Campanas Observatory and a s ...

2019

Impact of the 3D source geometry on time-delay measurements of lensed type-Ia supernovae

Frédéric Courbin, Vivien François Bonvin, Elodie Marie Charlène Savary, Martin Raoul Robert Millon, Olga Tihhonova, Hung-Hsu Chan

It has recently been proposed that gravitationally lensed type-Ia supernovae can provide microlensing-free time-delay measurements provided that the measurement is taken during the achromatic expansion phase of the explosion and that color light curves are ...

EDP SCIENCES S A2019

H0LiCOW-IX. Cosmographic analysis of the doubly imaged quasar SDSS 1206+4332 and a new measurement of the Hubble constant

Georges Meylan, Frédéric Courbin, Vivien François Bonvin, Riccardo Agnello, Hung-Hsu Chan, Adriano Agnello

We present a blind time-delay strong lensing (TDSL) cosmographic analysis of the doubly imaged quasar SDSS 1206+4332. We combine the relative time delay between the quasar images, Hubble Space Telescope imaging, the Keck stellar velocity dispersion of the ...

OXFORD UNIV PRESS2019