Person
Johan Richard
Related publications (40)
Revealing galaxy candidates out to z similar to 16 with JWST observations of the lensing cluster SMACS0723
Jean-Paul Richard Kneib, Hakim Atek, Johan Richard
One of the main goals of the JWST is to study the first galaxies in the Universe. We present a systematic photometric analysis of very distant galaxies in the first JWST deep field towards the massive lensing cluster SMACS0723. As a result, we report the d ...
OXFORD UNIV PRESS2023Uncovering a population of gravitational lens galaxies with magnified standard candle SN Zwicky
Cameron Alexander Campbell Lemon, Rémy Elie Joseph, Johan Richard
Detecting gravitationally lensed supernovae is among the biggest challenges in astronomy. It involves a combination of two very rare phenomena: catching the transient signal of a stellar explosion in a distant galaxy and observing it through a nearly perfe ...
NATURE PORTFOLIO2023A new step forward in realistic cluster lens mass modelling: analysis of Hubble Frontier Field Cluster Abell S1063 from joint lensing, X-ray, and galaxy kinematics data
Jean-Paul Richard Kneib, Benjamin Yvan Alexandre Clement, Benjamin Emmanuel Nicolas Beauchesne, Mathilde Jauzac, Johan Richard
We present a new method to simultaneously and self-consistently model the mass distribution of galaxy clusters that combines constraints from strong lensing features, X-ray emission, and galaxy kinematics measurements. We are able to successfully decompose ...
Oxford2023Probing the faint-end luminosity function of Lyman-alpha emitters at 3 < z < 7 behind 17 MUSE lensing clusters
Benjamin Yvan Alexandre Clement, Johan Richard
Context. This paper presents a study of the galaxy Lyman-alpha luminosity function (LF) using a large sample of 17 lensing clusters observed by the Multi Unit Spectroscopic Explorer (MUSE) at the ESO Very Large Telescope (VLT). The magnification resulting ...
Les Ulis Cedex A2023Improving parametric mass modelling of lensing clusters through a perturbative approach
Jean-Paul Richard Kneib, Benjamin Yvan Alexandre Clement, Benjamin Emmanuel Nicolas Beauchesne, Johan Richard
We present a new method to model the mass distribution of galaxy clusters that combines a parametric and a free-form approach to reconstruct cluster cores with strong lensing constraints. It aims at combining the advantages of both approaches, by keeping t ...
OXFORD UNIV PRESS2021The BUFFALO HST Survey
Jean-Paul Richard Kneib, Pascale Jablonka, David Richard Harvey, Benjamin Yvan Alexandre Clement, Mathilde Jauzac, Huanyuan Shan, Hakim Atek, Anja Von der Linden, Matthieu Schaller, Céline Tchernin, Richard Massey, Johan Richard
The Beyond Ultra-deep Frontier Fields and Legacy Observations (BUFFALO) is a 101 orbit + 101 parallel Cycle 25 Hubble Space Telescope (HST) Treasury program taking data from 2018 to 2020. BUFFALO will expand existing coverage of the Hubble Frontier Fields ...
IOP PUBLISHING LTD2020The core of the massive cluster merger MACS J0417.5-1154 as seen by VLT/MUSE
Jean-Paul Richard Kneib, David Richard Harvey, Mathilde Jauzac, Richard Massey, Johan Richard
We present a multiwavelength analysis of the core of the massive galaxy cluster MACS J0417.5-1154 (z = 0.441). Our analysis takes advantage of Very Large Telescope/Multi-Unit Spectroscopic Explorer observations which allowthe spectroscopic confirmation of ...
OXFORD UNIV PRESS2019Molecular clouds in the Cosmic Snake normal star-forming galaxy 8 billion years ago
Jean-Paul Richard Kneib, Daniel Pfenniger, Johan Richard
The cold molecular gas in contemporary galaxies is structured in discrete cloud complexes. These giant molecular clouds (GMCs), with 10(4)-10(7) solar masses (M-circle dot) and radii of 5-100 parsecs, are the seeds of star formation(1). Highlighting the mo ...
NATURE PUBLISHING GROUP2019Mapping substructure in the HST Frontier Fields cluster lenses and in cosmological simulations
Jean-Paul Richard Kneib, Mathilde Jauzac, Hakim Atek, Johan Richard, Cristina Popa
We map the lensing-inferred substructure in the first three clusters observed by the Hubble Space Telescope Frontier Fields (HSTFF) Initiative: Abell 2744 (z = 0.308), MACSJ 0416, (z = 0.396) and MACSJ 1149 (z = 0.543). Statistically resolving dark matter ...
Oxford Univ Press2017Molecular gas properties of a lensed star-forming galaxy at z similar to 3.6: a case study
Jean-Paul Richard Kneib, Benjamin Yvan Alexandre Clement, Johan Richard
We report on the galaxy MACSJ0032-arc at z(CO) = 3.6314 discovered during the Herschel Lensing snapshot Survey of massive galaxy clusters, and strongly lensed by the cluster MACSJ0032.1+1808. The successful detections of its rest-frame ultraviolet (UV), op ...
Edp Sciences S A2017