Publications de Olga Tihhonova

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

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

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

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

Frédéric Courbin, Georges Meylan, David Richard Harvey, Vivien François Bonvin, 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

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

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

Characterising the environment and the line of sight of gravitationally lensed quasars using weak lensing technique

Olga Tihhonova

Estimates of the Hubble constant from different cosmological probes produce discrepant results in the framework of the standard cosmological model. In order to assess whether this tension is coming from unaccounted systematic errors, or is hinting towards ...

EPFL2019

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

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

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 VIII. A weak-lensing measurement of the external convergence in the field of the lensed quasar HE0435-1223

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

2018

H0LiCOW-I. H-0 Lenses in COSMOGRAIL's Wellspring: program overview

Frédéric Courbin, Georges Meylan, Malte Tewes, Vivien François Bonvin, Olga Tihhonova, Adriano Agnello

Strong gravitational lens systems with time delays between the multiple images allow measurements of time-delay distances, which are primarily sensitive to the Hubble constant that is key to probing dark energy, neutrino physics and the spatial curvature o ...

Oxford Univ Press2017

Stellar kinematics using a third integral of motion: method and application on the Andromeda galaxy

Olga Tihhonova

We probe the feasibility of describing the structure of a multicomponent axisymmetric galaxy with a dynamical model based on the Jeans equations while taking into account a third integral of motion. We demonstrate that using the third integral in the form ...

Oxford Univ Press2016