Recherche

Afficher tous les résultats pour

Accueil

Personne

Frédéric Courbin

À propos
Confidentialité
Mentions légales

Graph Chatbot

Publications associées (229)

MUSE- inspired view of the quasar Q2059-360, its Lyman alpha blob, and its neighborhood

Pierre North, Frédéric Courbin, Claudio Gorgoni

The radio-quiet quasar Q2059-360 at redshift z = 3 : 08 is known to be close to a small Lyman ff blob (LAB) and to be absorbed by a proximate damped Ly ff (PDLA) system. Here, we present the Multi Unit Spectroscopic Explorer (MUSE) integral field spectrosc ...

Edp Sciences S A2017

Toward an Internally Consistent Astronomical Distance Scale

Frédéric Courbin

Accurate astronomical distance determination is crucial for all fields in astrophysics, from Galactic to cosmological scales. Despite, or perhaps because of, significant efforts to determine accurate distances, using a wide range of methods, tracers, and t ...

Springer2017

HOLiCOW - IV. Lens mass model of HE 0435-1223 and blind measurement of its time-delay distance for cosmology

Frédéric Courbin, Vivien François Bonvin

Strong gravitational lenses with measured time delays between the multiple images allow a direct measurement of the time-delay distance to the lens, and thus a measure of cosmological parameters, particularly the Hubble constant, H-0. We present a blind le ...

Oxford Univ Press2017

Detecting unresolved binary stars in Euclid VIS images

Frédéric Courbin, Thibault Adrien Kuntzer

Measuring a weak gravitational lensing signal to the level required by the next generation of space-based surveys demands exquisite reconstruction of the point-spread function (PSF). However, unresolved binary stars can significantly distort the PSF shape. ...

Edp Sciences S A2017

H0LiCOW. VI. Testing the fidelity of lensed quasar host galaxy reconstruction

Frédéric Courbin, Adriano Agnello

The empirical correlation between the mass of a supermassive black hole (M-BH) and its host galaxy properties is widely considered to be an evidence of their co-evolution. A powerful way to test the co-evolution scenario and learn about the feedback proces ...

Oxford Univ Press2017

A test for skewed distributions of dark matter, and a possible detection in galaxy cluster Abell 3827

Frédéric Courbin, Richard Massey, Rémy Elie Joseph, David Richard Harvey, Mathilde Jauzac

Simulations of self-interacting dark matter predict that dark matter should lag behind galaxies during a collision. If the interaction is mediated by a high-mass force carrier, the distribution of dark matter can also develop asymmetric dark matter tails. ...

Oxford Univ Press2017

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

Malte Tewes, Georges Meylan, Frédéric Courbin, 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

A detection of wobbling brightest cluster galaxies within massive galaxy clusters

Frédéric Courbin, Jean-Paul Richard Kneib, David Richard Harvey

A striking signal of dark matter beyond the standard model is the existence of cores in the centre of galaxy clusters. Recent simulations predict that a brightest cluster galaxy ( BCG) inside a cored galaxy cluster will exhibit residual wobbling due to pre ...

Oxford Univ Press2017

H0LiCOW-II. Spectroscopic survey and galaxy-group identification of the strong gravitational lens system HE 0435-1223

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

Galaxies located in the environment or along the line of sight towards gravitational lenses can significantly affect lensing observables, and can lead to systematic errors on the measurement of H-0 from the time-delay technique. We present the results of a ...

Oxford Univ Press2017

Models of the strongly lensed quasar DES J0408-5354

Eduardo Sanchez, Georges Meylan, Frédéric Courbin, 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

Discovery of the Lensed Quasar System DES J0408-5354

Eduardo Sanchez, Georges Meylan, Frédéric Courbin, Hung-Hsu Chan, Adriano Agnello

We report the discovery and spectroscopic confirmation of the quad-like lensed quasar system DES J0408-5354 found in the Dark Energy Survey (DES) Year 1 (Y1) data. This system was discovered during a search for DES Y1 strong lensing systems using a method ...

Iop Publishing Ltd2017

Proximity Operators for Phase Retrieval

Michaël Unser, Frédéric Courbin, Ferréol Arnaud Marie Soulez

We present a new formulation of a family of proximity operators that generalize the projector step for phase retrieval. These proximity operators for noisy intensity measurements can replace the classical "noise-free" projection in any projection-based alg ...

OSA2016

Back-Propagating the Light of Field Stars to Probe Telescope Mirrors Aberrations

Michaël Unser, Frédéric Courbin, Ferréol Arnaud Marie Soulez

We propose a wavefront-based method to estimate the PSF over the whole field of view. This method estimate the aberrations of all the mirrors of the telescope using only field stars. In this proof of concept paper, we described the method and present some ...

SPIE2016

ASTErIsM: application of topometric clustering algorithms in automatic galaxy detection and classification

Frédéric Courbin, Jean-Paul Richard Kneib, Danuta Janina Paraficz

We present a study on galaxy detection and shape classification using topometric clustering algorithms. We first use the DBSCAN algorithm to extract, from CCD frames, groups of adjacent pixels with significant fluxes and we then apply the DENCLUE algorithm ...

Oxford Univ Press2016

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

Malte Tewes, Georges Meylan, Frédéric Courbin, Thibault Adrien Kuntzer, Vivien François Bonvin

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 ...

Edp Sciences S A2016

Firedec: a two-channel finite-resolution image deconvolution algorithm

Nicolas Cantale, Malte Tewes, Georges Meylan, Frédéric Courbin, Pascale Jablonka

We present a two-channel deconvolution method that decomposes images into a parametric point-source channel and a pixelized extended-source channel. Based on the central idea of the deconvolution algorithm proposed by Magain et al. (1998, ApJ, 494, 472), t ...

Edp Sciences S A2016

Stellar classification from single-band imaging using machine learning

Malte Tewes, Frédéric Courbin, Thibault Adrien Kuntzer

Information on the spectral types of stars is of great interest in view of the exploitation of space-based imaging surveys. In this article, we investigate the classification of stars into spectral types using only the shape of their diffraction pattern in ...

Edp Sciences S A2016

Multi-band morpho-Spectral Component Analysis Deblending Tool (MuSCADeT): Deblending colourful objects

Frédéric Courbin, Rémy Elie Joseph

We introduce a new algorithm for colour separation and deblending of multi-band astronomical images called MuSCADeT which is based on Morpho-spectral Component Analysis of multi-band images. The MuSCADeT algorithm takes advantage of the sparsity of astrono ...

Edp Sciences S A2016

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

Georges Meylan, Frédéric Courbin, 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

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

Nicolas Cantale, Georges Meylan, Frédéric Courbin, Pascale Jablonka

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 ...

Edp Sciences S A2016

Page 9 sur 12