Publications associées à Effet Shapiro

LensWatch. I. Resolved HST Observations and Constraints on the Strongly Lensed Type Ia Supernova 2022qmx ("SN Zwicky")

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 Ltd2023

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

Gravitational causality and the self-stress of photons

Brando Bellazzini, Giulia Isabella

We study causality in gravitational systems beyond the classical limit. Using on-shell methods, we consider the 1-loop corrections from charged particles to the photon energy-momentum tensor - the self-stress - that controls the quantum interaction between ...

Springer Nature2022

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, 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

On the Propagation of Lightning-Radiated Electromagnetic Fields Across a Mountain

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Wenhao Hou, Qilin Zhang

In this article, the effect of a mountain located on the propagation path of lightning-radiated electromagnetic fields was systematically studied by using the two-dimensional finite-difference time-domain method (2-D FDTD), considering the influence of the ...

2020

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

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

A SHARP view of H0LiCOW: H-0 from three time-delay gravitational lens systems with adaptive optics imaging

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

We present the measurement of the Hubble constant, H-0, with three strong gravitational lens systems, We describe a blind analysis of both PG 1115+080 and 11E0435-1223 as well as an extension of our previous analysis of RXJ 1131-1231. For each lens, we com ...

OXFORD UNIV PRESS2019

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

Constraining the microlensing effect on time delays with a new time-delay prediction model in H-0 measurements

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

Time-delay strong lensing provides a unique way to directly measure the Hubble constant (H-0). The precision of the H-0 measurement depends on the uncertainties in the time-delay measurements, the mass distribution of the main deflector(s), and the mass di ...

OXFORD UNIV PRESS2018

COSMOGRAIL XVII. Time delays for the quadruply imaged quasar PG 1115+080

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

We present time-delay estimates for the quadruply imaged quasar PG 1115+080. Our results are based on almost daily observations for seven months at the ESO MPIA 2.2m telescope at La Silla Observatory, reaching a signal-to-noise ratio of about 1000 per quas ...

EDP SCIENCES S A2018

H0LiCOW-V. New COSMOGRAIL time delays of HE 0435-1223: H-0 to 3.8 per cent precision from strong lensing in a flat Lambda CDM model

Frédéric Courbin, Georges Meylan, Malte Tewes, Vivien François Bonvin

We present a new measurement of the Hubble Constant H-0 and other cosmological parameters based on the joint analysis of three multiply imaged quasar systems with measured gravitational time delays. First, we measure the time delay of HE 0435-1223 from 13- ...

Oxford Univ Press2017

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

Models of the strongly lensed quasar DES J0408-5354

Eduardo Sanchez, Frédéric Courbin, Georges Meylan, Vivien François Bonvin, Hung-Hsu Chan, Cameron Alexander Campbell Lemon, Adriano Agnello

We present detailed modelling of the recently discovered, quadruply lensed quasar J0408-5354, with the aim of interpreting its remarkable configuration: besides three quasar images (A, B, D) around the main deflector (G1), a fourth image (C) is significant ...

Oxford Univ Press2017

The relativistic foundations of synchrotron radiation

Giorgio Margaritondo

Special relativity (SR) determines the properties of synchrotron radiation, but the corresponding mechanisms are frequently misunderstood. Time dilation is often invoked among the causes, whereas its role would violate the principles of SR. Here it is show ...

International Union of Crystallography (IUCr)2017

Analysis of lightning electromagnetic field propagation in mountainous terrain and its effects on ToA-based lightning location systems

Marcos Rubinstein, Mohammad Azadifar, Farhad Rachidi-Haeri, Zhaoyang Wang, Keyhan Sheshyekani, Dongshuai Li, Qilin Zhang

In this paper, we analyze the propagation effects on lightning-radiated electromagnetic fields over mountainous terrain by using a three-dimensional (3-D) finite difference time domain (FDTD) method. We also discuss the time delay error in the time-of-arri ...

Amer Geophysical Union2016

On constraining the speed of gravitational waves following GW150914

Sergey Sibiryakov, Diego Blas Temino, Mikhail Ivanov

We point out that the observed time delay between the detection of the signal at the Hanford and Livingston LIGO sites from the gravitational wave event GW150914 places an upper bound on the speed of propagation of gravitational waves, c (gw) ae(2) 1.7 in ...

Springer Verlag2016

Traffic modeling, forecasting and assignment in large-scale networks

Mehmet Yildirimoglu

Today, the development and evaluation of traffic management strategies heavily relies on microscopic traffic simulation models. In case detailed input (i.e. od matrix, signal timings, etc.) is extracted and incorporated in these simulators, they can provid ...

EPFL2015

Cosmology From Gravitational Lens Time Delays And Planck Data

Frédéric Courbin, Georges Meylan, Malte Tewes

Under the assumption of a flat Lambda CDM cosmology, recent data from the Planck satellite point toward a Hubble constant that is in tension with that measured by gravitational lens time delays and by the local distance ladder. Prosaically, this difference ...

Iop Publishing Ltd2014

The Third Gravitational Lensing Accuracy Testing (Great3) Challenge Handbook

Frédéric Courbin, Marc Gentile, Richard Massey

The GRavitational lEnsing Accuracy Testing 3 (GREAT3) challenge is the third in a series of image analysis challenges, with a goal of testing and facilitating the development of methods for analyzing astronomical images that will be used to measure weak gr ...

University of Chicago Press2014