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Concept

Galaxie à anneau

Publications associées (32)

New insight on the nature of cosmic reionizers from the CEERS survey

Michaela Hirschmann

The Epoch of Reionization (EoR) began when galaxies grew in abundance and luminosity, so their escaping Lyman continuum (LyC) radiation started ionizing the surrounding neutral intergalactic medium (IGM). Despite significant recent progress, the nature and ...

Edp Sciences S A2024

The DESI one-per cent survey: exploring the halo occupation distribution of luminous red galaxies and quasi-stellar objects with ABACUSSUMMIT

Jiaxi Yu, Zheng Zheng, Antoine Philippe Jacques Rocher

We present the first comprehensive halo occupation distribution (HOD) analysis of the Dark Energy Spectroscopic Instrument (DESI) One-Percent Survey luminous red galaxy (LRG) and Quasi Stellar Object (QSO) samples. We constrain the HOD of each sample and t ...

2024

Extremely Red Galaxies at z=5-9 with MIRI and NIRSpec: Dusty Galaxies or Obscured Active Galactic Nuclei?

Michaela Hirschmann

We study a new population of extremely red objects (EROs) recently discovered by the James Webb Space Telescope (JWST) based on their NIRCam colors F277W - F444W > 1.5 mag. We find 37 EROs in the Cosmic Evolution Early Release Science Survey (CEERS) field ...

Iop Publishing Ltd2024

How much metal did the first stars provide to the ultra-faint dwarfs?

Pascale Jablonka, Yves Revaz, Mahsa Sanati, Fabien Nicolas Jeanquartier

Numerical simulations of dwarf galaxies have so far failed to reproduce the observed metallicity-luminosity relation, down to the regime of ultra-faint dwarfs (UFDs). We address this issue by exploring how the first generations of metal-free stars (Pop III ...

EDP SCIENCES S A2023

The DESI Survey Validation: Results from Visual Inspection of Bright Galaxies, Luminous Red Galaxies, and Emission-line Galaxies

Yi Zhang, Stewart Cole, Anand Stéphane Raichoor, Jiaxi Yu, Arjun Dey, Antoine Philippe Jacques Rocher

The Dark Energy Spectroscopic Instrument (DESI) Survey has obtained a set of spectroscopic measurements of galaxies to validate the final survey design and target selections. To assist in these tasks, we visually inspect DESI spectra of approximately 2500 ...

IOP Publishing Ltd2023

The DESI One-Percent Survey: Constructing Galaxy-Halo Connections for ELGs and LRGs Using Auto and Cross Correlations

Jiaxi Yu

In the current Dark Energy Spectroscopic Instrument (DESI) survey, emission line galaxies (ELGs) and luminous red galaxies (LRGs) are essential for mapping the dark matter distribution at < N(M)>. We measure the auto and cross correlation functions of ELGs ...

IOP Publishing Ltd2023

On the distribution of the cold neutral medium in galaxy discs

Robin Gopala Tress

The cold neutral medium (CNM) is an important part of the galactic gas cycle and a precondition for the formation of molecular and star-forming gas, yet its distribution is still not fully understood. In this work, we present extremely high resolution simu ...

OXFORD UNIV PRESS2023

A machine learning approach to correct for mass resolution effects in simulated halo clustering statistics

Cheng Zhao, Daniel Felipe Forero Sanchez

The increase in the observed volume in cosmological surveys imposes various challenges on simulation preparations. First, the volume of the simulations required increases proportionally to the observations. However, large-volume simulations are quickly bec ...

OXFORD UNIV PRESS2022

KiDS and Euclid: Cosmological implications of a pseudo angular power spectrum analysis of KiDS-1000 cosmic shear tomography

Yi Wang, Georges Meylan, Huanyuan Shan

We present a tomographic weak lensing analysis of the Kilo Degree Survey Data Release 4 (KiDS-1000), using a new pseudo angular power spectrum estimator (pseudo-C-l) under development for the ESA Euclid mission. Over 21 million galaxies with shape informat ...

EDP SCIENCES S A2022

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

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: N-body mock challenge for galaxy clustering measurements

Cheng Zhao

We develop a series of N-body data challenges, functional to the final analysis of the extended Baryon Oscillation Spectroscopic Survey (eBOSS) Data Release 16 (DR16) galaxy sample. The challenges are primarily based on high-fidelity catalogues constructed ...

OXFORD UNIV PRESS2021

Zero-metallicity Hypernova Uncovered by an Ultra-metal-poor Star in the Sculptor Dwarf Spheroidal Galaxy*

Pascale Jablonka

Although true metal-free "Population III" stars have so far escaped discovery, their nature, and that of their supernovae, is revealed in the chemical products left behind in the next generations of stars. Here we report the detection of an ultra-metal-poo ...

IOP PUBLISHING LTD2021

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: measurement of the BAO and growth rate of structure of the luminous red galaxy sample from the anisotropic correlation function between redshifts 0.6 and 1

Jean-Paul Richard Kneib, Cheng Zhao

We present the cosmological analysis of the configuration-space anisotropic clustering in the completed Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey (eBOSS) Data Release 16 galaxy sample. This sample consists of luminous red ...

OXFORD UNIV PRESS2021

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: N-body mock challenge for the eBOSS emission line galaxy sample

Cheng Zhao, Anand Stéphane Raichoor, Amélie Tamone

Cosmological growth can be measured in the redshift space clustering of galaxies targeted by spectroscopic surveys. Accurate prediction of clustering of galaxies will require understanding galaxy physics, which is a very hard and highly non-linear problem. ...

OXFORD UNIV PRESS2021

The AGORA High-resolution Galaxy Simulations Comparison Project. III. Cosmological Zoom-in Simulation of a Milky Way-mass Halo

Yves Revaz, Loïc Hausammann

We present a suite of high-resolution cosmological zoom-in simulations to z = 4 of a 10(12) M (circle dot) halo at z = 0, obtained using seven contemporary astrophysical simulation codes (Art-I, Enzo, Ramses, Changa, Gadget-3, Gear, and Gizmo) widely used ...

IOP PUBLISHING LTD2021

Chromosome maps of young LMC clusters: an additional case of coeval multiple populations

Carmela Lardo

Recent studies have revealed that the multiple populations (MPs) phenomenon does not occur only in ancient and massive Galactic globular clusters (GCs), but it is also observed in external galaxies, where GCs sample a wide age range with respect to the Mil ...

OXFORD UNIV PRESS2020

LESSER: a catalogue of spectroscopically selected sample of Lyman-alpha emitters lensed by galaxies

Jean-Paul Richard Kneib

We introduce the LEnSed laeS in the Eboss suRvey (LESSER) project, which aims to search for lensed Lyman-alpha emitters (LAEs) in the Extended Baryon Oscillation Spectroscopic Survey (eBOSS). The final catalogue contains 361 candidate lensing systems. The ...

OXFORD UNIV PRESS2020

Gaia Data Release 2 Variable stars in the colour-absolute magnitude diagram

Stephan Morgenthaler, Shuangqing Liao

Context. The ESA Gaia mission provides a unique time-domain survey for more than 1.6 billion sources with G less than or similar to 21 mag. ...

EDP SCIENCES S A2019

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

Survey of gravitationally-lensed objects in HSC imaging (SuGOHI) III. Statistical strong lensing constraints on the stellar IMF of CMASS galaxies

Hung-Hsu Chan

Context. The determination of the stellar initial mass function (IMF) of massive galaxies is one of the open problems in cosmology. Strong gravitational lensing is one of the few methods that allow us to constrain the IMF outside of the Local Group. Aims. ...

2019