Publications associées à Fourneau (constellation)

Constraints on the Hubble constant from supernova Refsdal's reappearance

Vivien François Bonvin, Mathilde Jauzac, Martin Raoul Robert Millon, Anja Von der Linden

The gravitationally lensed supernova Refsdal appeared in multiple images produced through gravitational lensing by a massive foreground galaxy cluster. After the supernova appeared in 2014, lens models of the galaxy cluster predicted that an additional ima ...

American Association for the Advancement of Science2023

Metallicity Distribution Functions of 13 Ultra-faint Dwarf Galaxy Candidates from Hubble Space Telescope Narrowband Imaging

Nicolas Lawrence Etienne Longeard

We present uniformly measured stellar metallicities of 463 stars in 13 Milky Way (MW) ultra-faint dwarf galaxies (UFDs; M-V = -7.1 to -0.8) using narrowband CaHK (F395N) imaging taken with the Hubble Space Telescope. This represents the largest homogeneous ...

Iop Publishing Ltd2023

New dwarf galaxy candidates in the sphere of influence of the Sombrero galaxy

Oliver Müller

We report the discovery of 40 new satellite dwarf galaxy candidates in the sphere of influence of the Sombrero Galaxy (M104), the most luminous galaxy in the Local Volume. Using the Subaru Hyper Suprime-Cam, we surveyed 14.4 deg(2) of its surroundings, ext ...

Oxford Univ Press2023

Fuelling the nuclear ring of NGC 1097

Robin Gopala Tress, Jiayi Sun

Galactic bars can drive cold gas inflows towards the centres of galaxies. The gas transport happens primarily through the so-called bar dust lanes, which connect the galactic disc at kpc scales to the nuclear rings at hundreds of pc scales much like two gi ...

2023

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

Pascale Jablonka, Yves Revaz, Mahsa Sanati

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

A possible dwarf galaxy satellite-of-satellite problem in ?CDM

Yves Revaz, Nick Heesters

Dark matter clusters on all scales, and it is therefore expected that even substructure should host its own substructure. Using the Extragalactic Distance Database, we searched for dwarf-galaxy satellites of dwarf galaxies, that is, satellite-of-satellite ...

EDP SCIENCES S A2023

The formation of the faintest galaxies in cosmological simulations: from the impact of primordial magnetic fields to the metal enrichment of present day dwarfs by first stars

Mahsa Sanati

In the theory of the bottom-up assembly of cosmic structures, one of the main challenges is to connect the smallest, most inconspicuous galaxies we observe today to the building blocks of more massive galaxies such as our own, the Milky Way. Do these so-ca ...

EPFL2023

The Pristine survey - XV. A CHIT ESPaDOnS view on the Milky Way halo and disc populations

Pascale Jablonka, Willem Suter, Carmela Lardo, Romain Ely Roland Lucchesi

We present a one-dimensional, local thermodynamic equilibrium homogeneous analysis of 132 stars observed at high resolution with ESPaDOnS. This represents the largest sample observed at high resolution (R similar to 40 000) from the Pristine survey. This s ...

OXFORD UNIV PRESS2022

Towards Efficient and Accurate Numerical Simulations of Galaxies using Task-based Parallelism and Application to Dwarf Galaxies

Loïc Hausammann

Numerical simulations are of a tremendous help to understand the growth of non-linear cosmological structures and how they lead to the formation of galaxies. In recent years, with the goal of improving their prediction power, new hydrodynamical techniques ...

EPFL2021

The accreted nuclear clusters of the Milky Way

Carmela Lardo

A number of the massive clusters in the halo, bulge, and disc of the Galaxy are not genuine globular clusters (GCs) but instead are different beasts altogether. They are the remnant nuclear star clusters (NSCs) of ancient galaxies since accreted by the Mil ...

OXFORD UNIV PRESS2021

Environmental processing in cluster core galaxies at z=1.7

Gianluca Castignani

Today, the brightest cluster galaxies (BCGs) are passive and very massive galaxies at the center of their clusters, and they still accrete mass through swallowing companions and gas from cooling flows. However their formation history is not well known. We ...

2020

Molecular gas in radio galaxies in dense megaparsec-scale environments at z=0.4-2.6

Gianluca Castignani

Context. Low luminosity radio galaxies (LLRGs) typically reside in dense megaparsec-scale environments and are often associated with brightest cluster galaxies (BCGs). They are an excellent tool to study the evolution of molecular gas reservoirs in giant e ...

EDP SCIENCES S A2019

Looking for dark matter trails in colliding galaxy clusters

Jean-Paul Richard Kneib, David Richard Harvey, Richard Massey

If dark matter interacts, even weakly, via non-gravitational forces, simulations predict that it will be preferentially scattered towards the trailing edge of the halo during collisions between galaxy clusters. This will temporarily create a non-symmetric ...

Oxford Univ Press2017

The formation of the Milky Way halo and its dwarf satellites; a NLTE-1D abundance analysis II. Early chemical enrichment

Pascale Jablonka, Pierre North

We present the non-local thermodynamic equilibrium (NLTE) abundances of up to 10 chemical species in a sample of 59 very metal-poor (VMP, -4

Edp Sciences S A2017

VLT/FLAMES spectroscopy of red giant branch stars in the Fornax dwarf spheroidal galaxy

Pascale Jablonka

Context. Fornax is one of the most massive dwarf spheroidal galaxies in the Local Group. The Fornax field star population is dominated by intermediate age stars but star formation was going on over almost its entire history. It has been proposed that Forna ...

EDP Sciences2014

Nucleosynthesis And The Inhomogeneous Chemical Evolution Of The Carina Dwarf Galaxy

Pascale Jablonka

The detailed abundances of 23 chemical elements in nine bright red giant branch stars in the Carina dwarf spheroidal galaxy are presented based on high-resolution spectra gathered at the Very Large Telescope (VLT) and Magellan telescopes. A spherical model ...

2012

Extremely metal-poor stars in classical dwarf spheroidal galaxies: Fornax, Sculptor, and Sextans

Pascale Jablonka, Pierre North, Martin Tafelmeyer

We present the results of a dedicated search for extremely metal-poor stars in the Fornax, Sculptor, and Sextans dSphs. Five stars were selected from two earlier VLT/Giraffe and HET/HRS surveys and subsequently followed up at high spectroscopic resolution ...

2010

Searching for dark matter in X-rays: how to check the dark matter origin of a spectral feature

Alexey Boyarsky, Oleg Ruchayskiy

A signal from decaying dark matter (DM) can be unambiguously distinguished from spectral features of astrophysical or instrumental origin by studying its spatial distribution. We demonstrate this approach by examining the recent claim of Loewenstein and Ku ...

Blackwell Publishing Ltd, Oxford2010

Dwarf Galaxies and Galaxy Halos : the First Stages of Galaxy Evolution

Martin Tafelmeyer

The various projects presented in this thesis contribute to the expansion of our knowledge and understanding of the fundamental processes involved in the formation of a galaxy and its stellar populations. For this purpose, two different techniques are appl ...

EPFL2010

The fundamental plane of EDisCS galaxies The effect of size evolution

Pascale Jablonka

We study the evolution of spectral early-type galaxies in clusters, groups, and the field up to redshift 0.9 using the ESO Distant Cluster Survey (EDisCS) dataset. We measure structural parameters (circularized half-luminosity radii R-e, surface brightness ...

2010