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Concept

Milieu intra-amas

Publications associées (31)

The effect of pressure-anisotropy-driven kinetic instabilities on magnetic field amplification in galaxy clusters

Salim Bennouna, Yoan Rappaz

Context. The intracluster medium (ICM) is the low-density diffuse gas that fills the space between galaxies within galaxy clusters. It is primarily composed of magnetized plasma, which reaches virial temperatures of up to 10(8) K, probably due to mergers o ...

Edp Sciences S A2024

Euclid: Calibrating photometric redshifts with spectroscopic cross-correlations

Yi Wang, Frédéric Courbin, Georges Meylan

Cosmological constraints from key probes of the Euclid imaging survey rely critically on the accurate determination of the true redshift distributions, n(z); of tomographic redshift bins. We determine whether the mean redshift, < z >, of ten Euclid tomogra ...

EDP SCIENCES S A2023

DESI mock challenge Halo and galaxy catalogues with the bias assignment method

Cheng Zhao, Yu Yu, Ginevra Favole

Context. We present a novel approach to the construction of mock galaxy catalogues for large-scale structure analysis based on the distribution of dark matter halos obtained with effective bias models at the field level. Aims. We aim to produce mock galaxy ...

EDP SCIENCES S A2023

The Cen A galaxy group: Dynamical mass and missing baryons

Oliver Müller

The nearby elliptical galaxy Centaurus A (Cen A) is surrounded by a flattened system of dwarf satellite galaxies with coherent motions. Using a novel Bayesian approach, we measured the mean rotation velocity nu(rot) and velocity dispersion sigma(int) of th ...

EDP SCIENCES S A2022

Constraining the baryonic feedback with cosmic shear using the DES Year-3 small-scale measurements

Yi Zhang, Eduardo Sanchez, Jonathan Andrew Blazek, Binglun Yin

We use the small scales of the Dark Energy Survey (DES) Year-3 cosmic shear measurements, which are excluded from the DES Year-3 cosmological analysis, to constrain the baryonic feedback. To model the baryonic feedback, we adopt a baryonic correction model ...

Oxford Univ Press2022

Hidden-nucleons neural-network quantum states for the nuclear many-body problem

Giuseppe Carleo

We generalize the hidden-fermion family of neural network quantum states to encompass both continuous and discrete degrees of freedom and solve the nuclear many-body Schrodinger equation in a systematically improvable fashion. We demonstrate that adding hi ...

AMER PHYSICAL SOC2022

Stellar metallicity gradients of Local Group dwarf galaxies

Pascale Jablonka, Yves Revaz

Aims. We explore correlations between the strength of metallicity gradients in Local Group dwarf galaxies and their stellar mass, star formation history timescales, and environment. Methods. We performed a homogeneous analysis of literature spectroscopic d ...

2022

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: 1000 multi-tracer mock catalogues with redshift evolution and systematics for galaxies and quasars of the final data release

Jean-Paul Richard Kneib, Cheng Zhao, Anand Stéphane Raichoor, Amélie Tamone

We produce 1000 realizations of synthetic clustering catalogues for each type of the tracers used for the baryon acoustic oscillation and redshift space distortion analysis of the Sloan Digital Sky Surveys-IV extended Baryon Oscillation Spectroscopic Surve ...

OXFORD UNIV PRESS2021

Hybrid Metal-Dielectric Metasurfaces for Refractive Index Sensing

Olivier Martin, Hatice Altug, Christian Santschi, Dordaneh Etezadi, Raziman Thottungal Valapu, Debdatta Ray

Hybrid metal-dielectric nanostructures have recently gained prominence because they combine strong field enhancement of plasmonic metals and the several low-loss radiation channels of dielectric resonators, which are qualities pertaining to the best of bot ...

AMER CHEMICAL SOC2020

The Pristine survey - X. A large population of low-metallicity stars permeates the Galactic disc

Pascale Jablonka, Pierre North, Nicolas Lawrence Etienne Longeard, Romain Ely Roland Lucchesi

The orbits of the least chemically enriched stars open a window on the formation of our Galaxy when it was still in its infancy. The common picture is that these low-metallicity stars are distributed as an isotropic, pressure-supported component since thes ...

OXFORD UNIV PRESS2020

The core of the massive cluster merger MACS J0417.5-1154 as seen by VLT/MUSE

Jean-Paul Richard Kneib, David Richard Harvey, Johannes Richard Cornelis Geerit Kruis

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 PRESS2019

A radio ridge connecting two galaxy clusters in a filament of the cosmic web

Claudio Gheller

Galaxy clusters are the most massive gravitationally bound structures in the Universe. They grow by accreting smaller structures in a merging process that produces shocks and turbulence in the intracluster gas. We observed a ridge of radio emission connect ...

American Association for the Advancement of Science2019

Is ram-pressure stripping an efficient mechanism to remove gas in galaxies?

Elena Ricciardelli

We study how the gas in a sample of galaxies (M-* > 10(9) M-circle dot) in clusters, obtained in a cosmological simulation, is affected by the interaction with the intracluster medium (ICM). The dynamical state of each elemental parcel of gas is studied us ...

Oxford Univ Press2017

MULTIWAVELENGTH STUDY OF QUIESCENT STATES OF Mrk 421 WITH UNPRECEDENTED HARD X-RAY COVERAGE PROVIDED BY NuSTAR IN 2013

Xin Chen, Thomas Günther Bretz

We present coordinated multiwavelength observations of the bright, nearby BL Lacertae object Mrk 421 taken in 2013 January-March, involving GASP-WEBT, Swift, NuSTAR, Fermi-LAT, MAGIC, VERITAS, and other collaborations and instruments, providing data from r ...

Iop Publishing Ltd2016

Strong lensing in the inner halo of galaxy clusters

Jean-Paul Richard Kneib

We present an axially symmetric formula to calculate the probability of finding gravitational arcs in galaxy clusters, being induced by their massive dark matter haloes, as a function of clusters redshifts and virial masses. The formula includes the ellipt ...

Oxford Univ Press2016

Hubble Frontier Fields: the geometry and dynamics of the massive galaxy cluster merger MACSJ0416.1-2403

Jean-Paul Richard Kneib, Hakim Atek, Benjamin Yvan Alexandre Clement, David Richard Harvey, Markus Rexroth

We use a joint optical/X-ray analysis to constrain the geometry and history of the ongoing merging event in the massive galaxy cluster MACSJ0416.1-2403 (z = 0.397). Our investigation of cluster substructure rests primarily on a combined strong-and weak-len ...

Wiley-Blackwell2015

Large scale structures around medium mass galaxy clusters at intermediate redshift

François Henri Ambroise Rérat

Theory predicts that galaxies are not randomly distributed in the Universe. They form a complex network of filamentary structures, the Cosmic Web, divided in clusters, groups, filaments and walls. This picture has been confirmed by the large galaxy redshif ...

EPFL2015

Warm-hot baryons comprise 5-10 per cent of filaments in the cosmic web

Jean-Paul Richard Kneib, Huanyuan Shan

Observations of the cosmic microwave background indicate that baryons account for 5 per cent of the Universe's total energy content(1). In the local Universe, the census of all observed baryons falls short of this estimate by a factor of two(2,3). Cosmolog ...

Nature Publishing Group2015

The last stages of star formation in the dwarf spheroidal galaxy Sextans

Romaine Theler

This thesis is anchored in the research of better understanding of the chemical evolution of galaxies. Many dwarf spheroidal galaxies (dSph) are orbiting the Milky Way displaying various star formation histories. The formation of these dwarf galaxies and t ...

EPFL2015

Weak lensing galaxy cluster field reconstruction

Jean-Paul Richard Kneib

In this paper, we compare three methods to reconstruct galaxy cluster density fields with weak lensing data. The first method called FLens integrates an inpainting concept to invert the shear field with possible gaps, and a multi-scale entropy denoising pr ...

Wiley-Blackwell2014