Publications de Benjamin Emmanuel Nicolas Beauchesne

Beyond MACS: physical properties of extremely X-ray luminous clusters at z > 0.5

We present a sample of over 100 highly X-ray luminous galaxy clusters (L-X,L-0.1-2.4keV similar to 10(45 )erg s(-1)) at z similar to 0.5-0.9, discovered by the extended Massive Cluster Survey (eMACS) in ROSAT All-Sky Survey (RASS) data. Follow-up observati ...

OXFORD UNIV PRESS2025

A comprehensive view on baryonic and dark matter components in massive galaxy clusters: Application to Abell S1063

Benjamin Emmanuel Nicolas Beauchesne

In the last decades, evidence has brought the standard cosmological model to include a significant dark sector with the elusive dark energy and dark matter (DM). Their mainly unknown properties constitute the most pressing questions in cosmology. As the ma ...

EPFL2025

The KALEIDOSCOPE survey: a new strong and weak gravitational lensing view of the massive galaxy cluster MACS J1423.8+2404

Benjamin Emmanuel Nicolas Beauchesne

We present a combined strong and weak gravitational-lensing analysis of the massive galaxy cluster MACS J1423.8+2404 (z = 0.545, MACS J1423 hereafter), one of the most dynamically relaxed and massive cool-core clusters discovered in the MAssive Cluster Sur ...

2024

Mass and light in galaxy clusters: The case of Abell 370

Benjamin Emmanuel Nicolas Beauchesne

In the cold dark matter (CDM) paradigm, an association between the hypothetic dark matter (DM) and its stellar counterpart is expected. However, parametric strong-lensing studies of galaxy clusters often display misleading features: DM components on the gr ...

EDP SCIENCES S A2024

A 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 ...

Oxford Univ Press2023

Precision Modeling of JWST's First Cluster Lens SMACS J0723.3-7327*

Jean-Paul Richard Kneib, Benjamin Yvan Alexandre Clement, Benjamin Emmanuel Nicolas Beauchesne

Exploiting the fundamentally achromatic nature of gravitational lensing, we present a lens model for the massive galaxy cluster SMACS J0723.3-7323 (SMACS J0723; z = 0.388) that significantly improves upon earlier work. Building on strong-lensing constraint ...

IOP Publishing Ltd2023

The JWST PEARLS View of the El Gordo Galaxy Cluster and of the Structure It Magnifies

Benjamin Emmanuel Nicolas Beauchesne

The massive galaxy cluster El Gordo (z = 0.87) imprints multitudes of gravitationally lensed arcs onto James Webb Space Telescope Near-Infrared Camera (NIRCam) images. Eight bands of NIRCam imaging were obtained in the "Prime Extragalactic Areas for Reioni ...

IOP Publishing Ltd2023

Dark matter in galaxy clusters: Parametric strong-lensing approach

Benjamin Emmanuel Nicolas Beauchesne

We present a parametric strong-lensing analysis of three massive galaxy clusters for which Hubble Space Telescope imaging is available, as well as spectroscopy of multiply imaged systems and galaxy cluster members. Our aim is to probe the inner shape of da ...

EDP SCIENCES S A2022

Improving 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 PRESS2021