Publications de Georges Meylan

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Gravitationally lensed quasars can be used to map the mass distribution in lensing galaxies and to estimate the Hubble constant H-0 by measuring the time delays between the quasar images. Here we report the measurement of two independent time delays in the ...

This work focusses on the pilot run of a simulation campaign aimed at investigating the spectroscopic capabilities of the Euclid NearInfrared Spectrometer and Photometer (NISP), in terms of continuum and emission line detection in the context of galaxy evo ...

The Euclid mission is generating a vast amount of imaging data in four broadband filters at a high angular resolution. This data will allow for the detailed study of mass, metallicity, and stellar populations across galaxies that will constrain their forma ...

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 ...

The Euclid Early Release Observations (ERO) showcase Euclid’s capabilities in advance of its main mission by targeting 17 astronomical objects, including galaxy clusters, nearby galaxies, globular clusters, and star-forming regions. A total of 24 hours of ...

Weak gravitational lensing has the potential to place tight constraints on the equation of the state of dark energy. However, this will only be possible if shear measurement methods can reach the required level of accuracy. We present a new method for meas ...

Context. The cosmological surveys that are planned for the current decade will provide us with unparalleled observations of the distribution of galaxies on cosmic scales, by means of which we can probe the underlying large-scale structure (LSS) of the Univ ...

Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved.The Euclid photometric survey of galaxy clusters stands as a powerful cosmological tool, with the capacity to significantly propel our understand ...

COSMOGRAIL is a long-term photometric monitoring of gravitationally lensed quasars aimed at implementing Refsdal's time-delay method to measure cosmological parameters, in particular H-0. Given the long and well sampled light curves of strongly lensed quas ...

We make use of the unprecedented depth, spatial resolution, and field of view of the Euclid Early Release Observations (EROs) of the Perseus galaxy cluster to detect and characterise the dwarf galaxy population in this massive system. Using a dedicated ann ...

Verifying the fully kinematic nature of the long-known cosmic microwave background (CMB) dipole is of fundamental importance in cosmology. In the standard cosmological model with the Friedman–Lemaitre–Robertson–Walker (FLRW) metric from the inflationary ex ...

Forthcoming large photometric surveys for cosmology require precise and accurate photometric redshift (photo-z) measurements for the success of their main science objectives. However, to date, no method has been able to produce photo-zs at the required acc ...

Pair-instability supernovae are theorized supernovae that have not yet been observationally confirmed. They are predicted to exist in low-metallicity environments. Because overall metallicity becomes lower at higher redshifts, deep near-infrared transient ...

We present a detailed study of the colours of late-type galaxy discs for ten of the EDisCS galaxy clusters with 0.5 less than or similar to z less than or similar to 0.8. Our cluster sample contains 172 spiral galaxies, and our control sample is composed o ...

This paper presents the specification, design, and development of the Visible Camera (VIS) on the European Space Agency’s Euclid mission. VIS is a large optical-band imager with a field of view of 0.54 deg2 sampled at 000 . 1 with an array of 609 Megapixel ...

We analyze the optical, UV, and X-ray microlensing variability of the lensed quasar SDSS J0924+ 0219 using six epochs of Chandra data in two energy bands (spanning 0.4-8.0 keV, or 1-20 keV in the quasar rest frame), 10 epochs of F275W (rest-frame 1089 angs ...

We report the discovery of three new cases of quasi-stellar objects (QSOs) acting as strong gravitational lenses on background emission line galaxies: SDSS J0827+5224 (z(QSO) = 0.293, z(s) = 0.412), SDSS J0919+2720 (z(QSO) = 0.209, z(s) = 0.558), SDSS J100 ...

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. ...

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 ...

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 ...

Georges Meylan

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COSMOGRAIL: the COSmological MOnitoring of GRAvItational lenses - VII. Time delays and the Hubble constant from WFI J2033-4723

Euclid preparation XXX. Performance assessment of the NISP red grism through spectroscopic simulations for the wide and deep surveys

Euclid preparation: LXVIII. Extracting physical parameters from galaxies with machine learning

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

Euclid: Early Release Observations – Programme overview and pipeline for compact- and diffuse-emission photometry

Hopfield neural network deconvolution for weak lensing measurement

XXXIV. The effect of linear redshift-space distortions in photometric galaxy clustering and its cross-correlation with cosmic shear

Euclid preparation: XXXIX. The effect of baryons on the halo mass function

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses XV. Assessing the achievability and precision of time-delay measurements

Euclid: Early Release Observations – Dwarf galaxies in the Perseus galaxy cluster

Euclid preparation XLVI. The near-infrared background dipole experiment with Euclid

Euclid preparation: X. The Euclid photometric-redshift challenge

Euclid: Searching for pair-instability supernovae with the Deep Survey

Disc colours in field and cluster spiral galaxies at 0.5 less than or similar to z less than or similar to 0.8

Euclid II. The VIS instrument

A Consistent Picture Emerges: A Compact X-Ray Continuum Emission Region In The Gravitationally Lensed Quasar Sdss J0924+0219

Three quasi-stellar objects acting as strong gravitational lenses

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

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

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