Home

Person

Georges Meylan

This person has left EPFL

About
Privacy
Disclaimer

Graph Chatbot

Related publications (177)

Page 4 of 9

Zooming into the broad line region of the gravitationally lensed quasar QSO 2237+0305 equivalent to the Einstein Cross III. Determination of the size and structure of the C-IV and C-III] emitting regions using microlensing

Frédéric Courbin, Georges Meylan, Alexander Patrick Eigenbrod

Aims. We aim to use microlensing taking place in the lensed quasar QSO 2237+0305 to study the structure of the broad line region (BLR) and measure the size of the region emitting the C-IV and C-III] lines. ...

2011

Euclid: Early Release Observations – The surface brightness and colour profiles of the far outskirts of galaxies in the Perseus cluster

Georges Meylan

The Perseus field captured by Euclid as part of its Early Release Observations provides a unique opportunity to study cluster environment ranging from outskirts to dense regions. Leveraging unprecedented optical and near-infrared depths, we investigate the ...

2025

The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2016 follow-up campaign - I. Overview and classification of candidates selected by two techniques

Frédéric Courbin, Georges Meylan, Eduardo Sanchez, Craig Matthew Smith, Hung-Hsu Chan, Riccardo Agnello, Joo Yeon Kim, Augusto Martins Lima, Karina Alexandra Rojas Olate, Cameron Alexander Campbell Lemon

The primary goals of the STRong lensing Insights into the Dark Energy Survey (STRIDES) collaboration are to measure the dark energy equation of state parameter and the free streaming length of dark matter. To this aim, STRIDES is discovering strongly lense ...

OXFORD UNIV PRESS2018

Euclid: the selection of quiescent and star-forming galaxies using observed colours

Yi Wang, Georges Meylan

The Euclid mission will observe well over a billion galaxies out to z similar to 6 and beyond. This will offer an unrivalled opportunity to investigate several key questions for understanding galaxy formation and evolution. The first step for many of these ...

OXFORD UNIV PRESS2020

Euclid: Early Release Observations – A preview of the Euclid era through a galaxy cluster magnifying lens

Jean-Paul Richard Kneib, Frédéric Courbin, Georges Meylan

We present the first analysis of the Euclid Early Release Observations (ERO) program that targets fields around two lensing clusters, Abell 2390 and Abell 2764. We use imaging data from the Visible instrument (VIS) and the Near-Infrared Spectrometer and Ph ...

2025

Euclid: The Early Release Observations Lens Search Experiment

Frédéric Courbin, Georges Meylan, Georgios Vernardos, Lucie Anemone Scharré, Bastien Clément

We investigated the ability of the Euclid telescope to detect galaxy-scale gravitational lenses. To do so, we performed a systematic visual inspection of the 0.7 deg2 Euclid Early Release Observations data towards the Perseus cluster using both the high-re ...

2025

Simultaneous estimation of time delays and quasar structure

Frédéric Courbin, Georges Meylan, Christel Vuissoz

We expand our Bayesian Monte Carlo method for analyzing the light curves of gravitationally lensed quasars to simultaneously estimate time delays and the sizes of quasar continuum emission regions including their mutual uncertainties. We apply the method t ...

2008

Euclid: Testing photometric selection of emission-line galaxy targets?

Frédéric Courbin, Georges Meylan

Multi-object spectroscopic galaxy surveys typically make use of photometric and colour criteria to select their targets. That is not the case of Euclid, which will use the NISP slitless spectrograph to record spectra for every source over its field of view ...

2024

Further Evidence That Quasar X-Ray Emitting Regions Are Compact: X-Ray And Optical Microlensing In The Lensed Quasar Q J0158-4325

Frédéric Courbin, Georges Meylan, Malte Tewes

We present four new seasons of optical monitoring data and six epochs of X-ray photometry for the doubly imaged lensed quasar Q J0158-4325. The high-amplitude, short-period microlensing variability for which this system is known has historically precluded ...

Iop Publishing Ltd2012

Euclid preparation XVI. Exploring the ultra-low surface brightness Universe with Euclid/VIS

Georges Meylan, Gianluca Castignani

Context. While Euclid is an ESA mission specifically designed to investigate the nature of dark energy and dark matter, the planned unprecedented combination of survey area (similar to 15000 deg(2)), spatial resolution, low sky-background, and depth also m ...

EDP SCIENCES S A2022

Euclid: Forecast constraints on consistency tests of the ?CDM model

Frédéric Courbin, Georges Meylan

Context. The standard cosmological model is based on the fundamental assumptions of a spatially homogeneous and isotropic universe on large scales. An observational detection of a violation of these assumptions at any redshift would immediately indicate th ...

EDP SCIENCES S A2022

Euclid preparation XLI. Galaxy power spectrum modelling in real space

Frédéric Courbin, Georges Meylan

We investigate the accuracy of the perturbative galaxy bias expansion in view of the forthcoming analysis of the Euclid spectroscopic galaxy samples. We compare the performance of a Eulerian galaxy bias expansion using state-of-the-art prescriptions from t ...

2024

Observations Of The Gas Reservoir Around A Star-Forming Galaxy In The Early Universe

Georges Meylan

We present a high signal-to-noise spectrum of a bright galaxy at z = 4.9 in 14 hr of integration on VLT FORS2. This galaxy is extremely bright, i(850) = 23.10 +/- 0.01, and is strongly lensed by the foreground massive galaxy cluster A1689 (z = 0.18). Stell ...

2008

Euclid: Early Release Observations of diffuse stellar structures and globular clusters as probes of the mass assembly of galaxies in the Dorado group?

Georges Meylan, Olivia Mueller

Deep surveys have helped to unveil the history of past and present galaxy mergers, and, in particular, uncovering their tidal debris and co-located globular clusters (GCs). Euclid’s unique combination of capabilities (spatial resolution, depth, and wide sk ...

2025

Euclid preparation: L. Calibration of the halo linear bias in Λ(v)CDM cosmologies

Frédéric Courbin, Georges Meylan

The Euclid mission, designed to map the geometry of the dark Universe, presents an unprecedented opportunity for advancing our understanding of the cosmos through its photometric galaxy cluster survey. Central to this endeavor is the accurate calibration o ...

2024

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

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

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

Euclid preparation XLVIII. The pre-launch Science Ground Segment simulation framework

Frédéric Courbin, Georges Meylan, Benjamin Yvan Alexandre Clement

Context. The European Space Agency’s Euclid mission is one of a raft of forthcoming large-scale cosmology surveys that will map the large-scale structure in the Universe with unprecedented precision. The mission will collect a vast amount of data that will ...

2024

Euclid Preparation. XIV. The Complete Calibration of the Color-Redshift Relation (C3R2) Survey: Data Release 3

Georges Meylan, Gianluca Castignani

The Complete Calibration of the Color-Redshift Relation (C3R2) survey is obtaining spectroscopic redshifts in order to map the relation between galaxy color and redshift to a depth of i similar to 24.5 (AB). The primary goal is to enable sufficiently accur ...

IOP PUBLISHING LTD2021

Evaluating the effect of stellar multiplicity on the point spread function of space-based weak lensing surveys

Frédéric Courbin, Georges Meylan, Thibault Adrien Kuntzer

The next generation of space-based telescopes used for weak lensing surveys will require exquisite point spread function (PSF) determination. Previously negligible effects may become important in the reconstruction of the PSF, in part because of the improv ...

Edp Sciences S A2016

Euclid: Cosmology forecasts from the void-galaxy cross-correlation function with reconstruction

Frédéric Courbin, Georges Meylan

We have investigated the cosmological constraints that can be expected from measurement of the cross-correlation of galaxies with cosmic voids identified in the Euclid spectroscopic survey, which will include spectroscopic information for tens of millions ...

EDP SCIENCES S A2023