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Concept

Protogalaxie

Publications associées (29)

The Origins of Gas Accreted by Supermassive Black Holes: The Importance of Recycled Gas

Michaela Hirschmann

We investigate the fueling mechanisms of supermassive black holes (SMBHs) by analyzing 10 zoom-in cosmological simulations of massive galaxies, with stellar masses 1011-12 M circle dot and SMBH masses 108.9-9.7 M circle dot at z = 0, featuring various majo ...

Iop Publishing Ltd2024

Strong gravitational lensing's 'external shear' is not shear

David Richard Harvey

The distribution of mass in galaxy-scale strong gravitational lenses is often modelled as an elliptical power-law plus 'external shear', which notionally accounts for neighbouring galaxies and cosmic shear along our line of sight. A small amount of externa ...

Oxford Univ Press2024

Gravitationally lensed quasars in Gaia - IV. 150 new lenses, quasar pairs, and projected quasars

Frédéric Courbin, Aymeric Alexandre Galan, Cameron Alexander Campbell Lemon

We report the spectroscopic follow-up of 175 lensed quasar candidates selected using Gaia Data Release 2 observations following Paper III of this series. Systems include 86 confirmed lensed quasars and a further 17 likely lensed quasars based on imaging an ...

OXFORD UNIV PRESS2023

Semi-analytic forecasts for Roman - the beginning of a new era of deep-wide galaxy surveys

Michaela Hirschmann

The Nancy Grace Roman Space Telescope, NASA's next flagship observatory, will redefine deep-field galaxy survey with a field of view two orders of magnitude larger than Hubble and an angular resolution of matching quality. These future deep-wide galaxy sur ...

OXFORD UNIV PRESS2023

A Long Time Ago in a Galaxy Far, Far Away: A Candidate z similar to 12 Galaxy in Early JWST CEERS Imaging

Michaela Hirschmann

We report the discovery of a candidate galaxy with a photo -z of z similar to 12 in the first epoch of the James Webb Space Telescope (JWST) Cosmic Evolution Early Release Science Survey. Following conservative selection criteria, we identify a source with ...

IOP Publishing Ltd2022

Sleptonic SUSY: from UV framework to IR phenomenology

Majid Ekhterachian

We study an attractive scenario, "Sleptonic SUSY", which reconciles the 125 GeV Higgs scalar and the non-observation of superpartners thus far with potentially pivotal roles for slepton phenomenology: providing viable ongoing targets for LHC discovery, inc ...

Springer Nature2022

Regulation of sedimentation rate shapes the evolution of multicellularity in a close unicellular relative of animals

Omaya Pierre Dudin

Significant increases in sedimentation rate accompany the evolution of multicellularity. These increases should lead to rapid changes in ecological distribution, thereby affecting the costs and benefits of multicellularity and its likelihood to evolve. How ...

PUBLIC LIBRARY SCIENCE2022

Next generation modeling techniques for strong gravitational lensing and measuring the Hubble constant

Aymeric Alexandre Galan

For many years, observations of the Universe suggest a series problems with our theoretical models, particularly its dark energy and dark matter components. Fortunately, the Universe also provides us with a tool to solve these problems, called strong gravi ...

EPFL2022

Finite-resolution Deconvolution of Multiwavelength Imaging of 20,000 Galaxies in the COSMOS Field: The Evolution of Clumpy Galaxies over Cosmic Time

Pascale Jablonka

Compact star-forming clumps observed in distant galaxies are often suggested to play a crucial role in galaxy assembly. In this paper, we use a novel approach of applying finite-resolution deconvolution on ground-based images of the COSMOS field to resolve ...

IOP Publishing Ltd2022

Atomic data for the

Carmela Lardo

Context. We describe the atomic and molecular data that were used for the abundance analyses of FGK-type stars carried out within the Gaia-ESO Public Spectroscopic Survey in the years 2012 to 2019. The Gaia-ESO Survey is one among several current and futur ...

EDP SCIENCES S A2021

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

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

The BUFFALO HST Survey

Jean-Paul Richard Kneib, Pascale Jablonka, Huanyuan Shan, Hakim Atek, David Richard Harvey, Benjamin Yvan Alexandre Clement

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 LTD2020

Controlling and leveraging small-scale information in tomographic galaxy-galaxy lensing

Jonathan Andrew Blazek

The tangential shear signal receives contributions from physical scales in the galaxy-matter correlation function well below the transverse scale at which it is measured. Since small scales are difficult to model, this non-locality has generally required s ...

OXFORD UNIV PRESS2020

The chemical evolution of the dwarf spheroidal galaxy Sextans

Pascale Jablonka, Carmela Lardo, Pierre North, Romain Ely Roland Lucchesi, Romaine Theler

We present our analysis of the FLAMES dataset targeting the central 25 ' region of the Sextans dwarf spheroidal galaxy (dSph). This dataset is the third major part of the high-resolution spectroscopic section of the ESO large program 171.B-0588(A) obtained ...

EDP SCIENCES S A2020

Sparse Linear Inversion for Strong Gravitational Lenses Reconstruction, Component Separation from Morphological Component Analysis with Multiple Discrimination Criteria

Rémy Elie Joseph

Strong gravitational is a natural phenomenon that produces distorted images of distant galaxies due to massive galaxies or clusters, called deflectors or lenses, lying along the line of sight. Due to the mass of the deflector, and as a result of general re ...

EPFL2018

What is the Milky Way outer halo made of? High resolution spectroscopy of distant red giants

Pascale Jablonka, Pierre North

In a framework where galaxies form hierarchically, extended stellar haloes are predicted to be an ubiquitous feature around Milky Way-like galaxies and to consist mainly of the shredded stellar component of smaller galactic systems. The type of accreted st ...

Edp Sciences S A2017

Precise measurements of time delays in gravitationally lensed quasars for competitive and independent determination of the Hubble constant

Vivien François Bonvin

During these last decades, by virtue of observations, the Standard Cosmological Model has emerged, providing a description of the Universe's evolution using a minimal set of independent constraints - the cosmological parameters. Among them is the expansion ...

EPFL2017

Clustering properties of g-selected galaxies at z similar to 0.8

Jean-Paul Richard Kneib, David Schlegel, Timothée Guy Olivier Delubac, Ginevra Favole

Current and future large redshift surveys, as the Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey (SDSS-IV/eBOSS) or the Dark Energy Spectroscopic Instrument (DESI), will use emission-line galaxies (ELGs) to probe cosmological ...

Wiley-Blackwell2016

The SDSS-III BOSS quasar lens survey: discovery of 13 gravitationally lensed quasars

Jean-Paul Richard Kneib

We report the discovery of 13 confirmed two-image quasar lenses from a systematic search for gravitationally lensed quasars in the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). We adopted a methodology similar to that used in the SDSS Quasar Len ...

Oxford Univ Press2016