Publications de Romain Ely Roland Lucchesi

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

The Pristine dwarf galaxy survey - IV. Probing the outskirts of the dwarf galaxy Bootes I

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

We present a new spectroscopic study of the dwarf galaxy Bootes I (Boo I) with data from the Anglo-Australian Telescope and its AAOmega spectrograph together with the Two Degree Field multi-object system. We observed 36 high-probability Boo I stars selecte ...

OXFORD UNIV PRESS2022

The first generations of stars in the Local Group

Romain Ely Roland Lucchesi

The different projects of this thesis contribute to improving our understanding of the early chemical evolution of the galaxies. The standard cosmological model states an hierarchical formation of the galaxies, the dwarf galaxies being the first stellar sy ...

EPFL2022

The pristine dwarf-galaxy survey - III. Revealing the nature of the Milky Way globular cluster Sagittarius II

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

We present a new spectroscopic study of the faint Milky Way satellite Sagittarius II. Using multiobject spectroscopy from the Fibre Large Array Multi-Element Spectrograph, we supplement the data set of Longeard et al. with 47 newly observed stars, 19 of wh ...

OXFORD UNIV PRESS2021

The chemical evolution of the dwarf spheroidal galaxy Sextans

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

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

Homogeneity in the early chemical evolution of the Sextans dwarf spheroidal galaxy

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

We present the high-resolution spectroscopic analysis of two new extremely metal-poor star (EMPS) candidates in the dwarf spheroidal galaxy Sextans. These targets were preselected from medium-resolution spectra centered around the CaII triplet in the near- ...

EDP SCIENCES S A2020

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

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

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 Pristine survey VI. The first three years of medium-resolution follow-up spectroscopy of Pristine EMP star candidates

Carmela Lardo, Romain Ely Roland Lucchesi, Nicolas Lawrence Etienne Longeard

We present the results of a 3-yr long, medium-resolution spectroscopic campaign aimed at identifying very metal -poor stars from candidates selected with the CaHK, metallicitysensitive Pristine survey. The catalogue consists of a total of 1007 stars, and i ...

OXFORD UNIV PRESS2019