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Concept

Superamas de galaxies

Publications associées (32)

Hydrodynamical simulations of merging galaxy clusters: giant dark matter particle colliders, powered by gravity

David Richard Harvey

Terrestrial particle accelerators collide charged particles, then watch the trajectory of outgoing debris - but they cannot manipulate dark matter. Fortunately, dark matter is the main component of galaxy clusters, which are continuously pulled together by ...

Oxford Univ Press2024

GHOST commissioning science results - II: a very metal-poor star witnessing the early galactic assembly

Pascale Jablonka

This study focuses on Pristine_180956.78-294759.8 (hereafter P180956, [Fe/H] = -1.95 +/- 0.02), a star selected from the Pristine Inner Galaxy Survey (PIGS), and followed-up with the recently commissioned Gemini High-resolution Optical SpecTrograph (GHOST) ...

Oxford Univ Press2024

Limit on the intergalactic magnetic field from the ultrahigh-energy cosmic ray hotspot in the Perseus-Pisces region

Andrii Neronov, Oleg Kalashev

The Telescope Array Collaboration has reported an evidence for existence of a source of ultrahigh energy cosmic ray events in Perseus-Pisces supercluster. We show that the mere existence of such a source imposes an upper bound on the strength of intergalac ...

American Physical Society2023

Cosmic void exclusion models and their impact on the distance scale measurements from large-scale structure

Jean-Paul Richard Kneib, Cheng Zhao, Daniel Felipe Forero Sanchez, Amélie Tamone, Andrei Variu

Baryonic Acoustic Oscillations (BAOs) studies based on the clustering of voids and matter tracers provide important constraints on cosmological parameters related to the expansion of the Universe. However, modelling the void exclusion effect is an importan ...

OXFORD UNIV PRESS2023

Probing the nature of Dark Energy through the study of large scale structures using spectroscopic surveys and their simulations

Andrei Variu

Measurements of large-scale structure (LSS), as performed on the largest 3D map of over two million extragalactic sources from the Sloan Digital Sky Survey, together with measurements of the cosmic microwave background (CMB) anisotropies, are in complete a ...

EPFL2023

Virgo Filaments. II. Catalog and First Results on the Effect of Filaments on Galaxy Properties

Pascale Jablonka, Gianluca Castignani

Virgo is the nearest galaxy cluster; it is thus ideal for studies of galaxy evolution in dense environments in the local universe. It is embedded in a complex filamentary network of galaxies and groups, which represents the skeleton of the large-scale Lani ...

IOP Publishing Ltd2022

Cosmic void baryon acoustic oscillation measurement: evaluation of sensitivity to selection effects

Jean-Paul Richard Kneib, Cheng Zhao, Daniel Felipe Forero Sanchez, Amélie Tamone, Andrei Variu

Cosmic voids defined as a subset of Delaunay triangulation (DT) circumspheres have been used to measure the baryon acoustic oscillations (BAO) scale; providing tighter constraints on cosmological parameters when combined with matter tracers. These voids ar ...

OXFORD UNIV PRESS2022

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

Metallicity Distribution Function of the Eridanus II Ultra-faint Dwarf Galaxy from Hubble Space Telescope Narrowband Imaging

Nicolas Lawrence Etienne Longeard

We use deep narrowband CaHK (F395N) imaging taken with the Hubble Space Telescope (HST) to construct the metallicity distribution function (MDF) of Local Group ultra-faint dwarf galaxy Eridanus II (Eri II). When combined with archival F475W and F814W data, ...

IOP Publishing Ltd2022

Virgo filaments I. Processing of gas in cosmological filaments around the Virgo cluster

Pascale Jablonka, Gianluca Castignani

It is now well established that galaxies have different morphologies, gas contents, and star formation rates (SFR) in dense environments like galaxy clusters. The impact of environmental density extends to several virial radii, and galaxies appear to be pr ...

EDP SCIENCES S A2021

The GOGREEN survey: transition galaxies and the evolution of environmental quenching

Pascale Jablonka, Hung-Hsu Chan

We measure the rate of environmentally driven star formation quenching in galaxies at z similar to 1, using eleven massive () galaxy clusters spanning a redshift range 1.0 < z < 1.4 from the GOGREEN sample. We identify three different types of transition g ...

OXFORD UNIV PRESS2021

Molecular gas in CLASH brightest cluster galaxies at z similar to 0.2-0.9

Pascale Jablonka, Gianluca Castignani

Brightest cluster galaxies (BCGs) are excellent laboratories for the study of galaxy evolution in dense Mpc-scale environments. We used the IRAM-30 m to observe, in CO(1 -> 0), CO(2 -> 1), CO(3 -> 2), or CO(4 -> 3), 18 BCGs at z similar to 0.2-0.9 drawn fr ...

EDP SCIENCES S A2020

Molecular gas and star formation activity in luminous infrared galaxies in clusters at intermediate redshifts

Pascale Jablonka, Gianluca Castignani, Damien Louis Alexandre Spérone-Longin

We investigate the role of dense megaparsec-scale environments in processing molecular gas of cluster galaxies as they fall into the cluster cores. We selected a sample of similar to 20 luminous infrared galaxies (LIRGs) belonging to intermediate-redshift ...

EDP SCIENCES S A2020

Structural Snapshots of Cluster Growth from {U6 } to {U38 } During the Hydrolysis of UCl4

Marinella Mazzanti, Farzaneh Fadaei Tirani, Lucile Sylvie Danielle Chatelain, Radmila Faizova

Herein we report the assembly of large uranium(IV) clusters with novel nuclearities and/or shapes from the controlled hydrolysis of UCl4 in organic solution and in the presence of the benzoate ligands. {U6}, {U13}, {U16}, {U24}, {U38} oxo and oxo/hydroxo c ...

Wiley-VCH Verlag GmbH2019

Euclid preparation III. Galaxy cluster detection in the wide photometric survey, performance and algorithm selection

Gianluca Castignani, Marina Ricci, Adam Julian Richardson

Galaxy cluster counts in bins of mass and redshift have been shown to be a competitive probe to test cosmological models. This method requires an efficient blind detection of clusters from surveys with a well-known selection function and robust mass estima ...

EDP Sciences2019

Preprocessing among the Infalling Galaxy Population of EDisCS Clusters

Pascale Jablonka

We present results from a low-resolution spectroscopic survey for 21 galaxy clusters at 0.4 < z < 0.8 selected from the ESO Distant Cluster Survey. We measured spectra using the low-dispersion prism in IMACS on the Magellan Baade telescope and calculate re ...

IOP PUBLISHING LTD2019

CODEX weak lensing: concentration of galaxy clusters at z similar to 0.5

Jean-Paul Richard Kneib, Huanyuan Shan

We present a stacked weak-lensing analysis of 27 richness selected galaxy clusters at 0.40

Oxford Univ Press2017

A detection of wobbling brightest cluster galaxies within massive galaxy clusters

Jean-Paul Richard Kneib, Frédéric Courbin, 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

Molecular 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

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

Strong-lensing analysis of MACSJ0717.5+3745 from Hubble Frontier Fields observations: How well can the mass distribution be constrained?

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

We present a strong-lensing analysis of MACSJ0717.5+3745 (hereafter MACS J0717), based on the full depth of the Hubble Frontier Field (HFF) observations, which brings the number of multiply imaged systems to 61, ten of which have been spectroscopically con ...

Edp Sciences S A2016