activity
20182026
most citedTracing the formation of the Milky Way through ultra metal-poor stars

120 citations · 1.3k across the 63 of their papers we have counts for

collaborators

64 papers

astro-ph.GA2026

The Pristine survey XXIX. Data Release 2: Photometric metallicities for 15 millions stars down to

Zhen Yuan, Anke Ardern-Arentsen, Nicolas F. Martin +15

Tailored narrow-band photometric observations are an efficient way to measure the metallicity of Milky Way stars. The Pristine survey has been mapping the northern sky since 2015 u…

astro-ph.IM2026

HRMOS: A High-Resolution Multi-Object Spectrograph for the VLT

Laura Magrini, Thomas Bensby, Sofia Randich +174

This White Paper presents the scientific rationale and instrument concept for HRMOS (High-Resolution Multi-Object Spectrograph), a next-generation instrument proposed for the ESO V…

astro-ph.GA2026

The Pristine Dwarf Galaxy Survey -- VII. The metallicity distributions of 12 Milky Way faint satellites

S. Taibi, P. Jablonka, N. Longeard +10

Spectroscopic studies of ultra-faint dwarf galaxies are typically limited to small samples of stars due to the scarcity of sufficiently bright targets. The small number statistics…

astro-ph.GA2026★ 1 cited

Galactic Archaeology with the Subaru `Ōnohi`ula Prime Focus Spectrograph Strategic Program

Masashi Chiba, Rosemary F. G. Wyse, Evan N. Kirby +48

The recently commissioned Subaru `Ōnohi`ula Prime Focus Spectrograph (PFS) will obtain spectra from nearly 2,400 fibers that cover 1.24 square degrees. The 360 night Subaru Strateg…

astro-ph.GA2026

The primordial nature of the C-19 stellar stream

Kim A. Venn, Zhen Yuan, Nicolas F. Martin +32

Stellar streams, remnants of compact star systems stretched out by the tidal forces of the Milky Way, offer a unique way to study stellar populations that formed billions of years…

astro-ph.GA2026★ 1 cited

HR-GO II: chemical abundances of low- retrograde dynamically-tagged-groups: Revealing Thamnos as a very metal-poor substructure

Renjing Xie, Zhen Yuan, Haining Li +12

Milky Way halo substructures identified in dynamical space are known to suffer from contamination from the Milky Way in-situ stars, which makes their accreted origins uncertain. We…

astro-ph.GA2025

Confirming membership in Local Group galaxies with the Dark Energy Spectroscopic Instrument Data Release 1

Federico Sestito, Chiaki Kobayashi

We use the Dark Energy Spectroscopic Instrument Data Release 1 (DESI DR1) to identify stellar members of the Local Group dwarf galaxies. We cross-match DESI targets with candidate…

astro-ph.SR2025★ 4 cited

An Unsupervised Machine Learning Approach to Identify Spectral Energy Distribution Outliers: Application to the S-PLUS DR4 data

F. Quispe-Huaynasi, F. Roig, N. Holanda +12

Identification of specific stellar populations using photometry for spectroscopic follow-up is a first step to confirm and better understand their nature. In this context, we prese…

astro-ph.GA2025

The Pristine Dwarf-Galaxy survey -- VI. A VLT/FLAMES spectroscopic study of the dwarf galaxy Boötes II

Nicolas Longeard, Pascale Jablonka, Giuseppina Battaglia +4

The Milky Way has a large population of dwarf galaxy satellites. Their properties are sensitive to both cosmology and the physical processes underlying galaxy formation, but these…

astro-ph.GA2025★ 2 cited

UNIONS: The Ultraviolet Near-Infrared Optical Northern Survey

Stephen Gwyn, Alan W. McConnachie, Jean-Charles Cuillandre +86

The Ultraviolet Near-Infrared Optical Northern Survey (UNIONS) is a "collaboration of collaborations" that is using the Canada-France-Hawai'i Telescope, the Pan-STARRS telescopes,…

astro-ph.GA2025

GHOST commissioning science results -- IV: Chemodynamical analyses of Milky Way satellites Sagittarius II and Aquarius II

Daria Zaremba, Kim Venn, Christian R. Hayes +28

We present Gemini/GHOST high-resolution spectra of five stars observed in two low surface brightness Milky Way satellites, Sagittarius II (Sgr2) and Aquarius II (Aqu2). For Aqu2, t…

astro-ph.GA2025★ 5 cited

The Pristine survey: XXVII. The extremely metal-poor stream C-19 stretches over more than 100 degrees

Zhen Yuan, Tadafumi Matsuno, Tatyana Sitnova +14

The discovery of the most metal-poor stream, C-19, provides us with a fossil record of a stellar structure born very soon after the Big Bang. In this work, we search for new C-19 m…

astro-ph.SR2025

The elderly among the oldest: new evidence for extremely metal-poor RR Lyrae stars

Valentina D'Orazi, Vittorio F. Braga, Giuseppe Bono +21

We performed a detailed spectroscopic analysis of three extremely metal-poor RR Lyrae stars, exploring uncharted territories at these low metallicities for this class of stars. Usi…

astro-ph.GA2025

The S-PLUS Ultra-Short Survey: Photometric Re-calibration with the BEst STar Database

Xiaolu Li, Kai Xiao, Yang Huang +15

We present an independent validation and comprehensive re-calibration of S-PLUS Ultra-Short Survey (USS) DR1 12-band photometry using about 30,000--70,000 standard stars from the B…

astro-ph.GA2024

The Pristine Inner Galaxy Survey (PIGS) XI: Revealing the chemical evolution of the interacting Sagittarius dwarf galaxy

Sara Vitali, Alvaro Rojas-Arriagada, Paula Jofré +9

The Sagittarius dwarf spheroidal galaxy (Sgr dSph) is a satellite orbiting the Milky Way that has experienced multiple stripping events due to tidal interactions with our Galaxy. I…

astro-ph.GA2024

An ancient system hidden in the Galactic plane?

Federico Sestito, Emma Fernandez-Alvar, Rebecca Brooks +19

We analyse high signal-to-noise ESPaDOnS/CFHT spectra of 20 very metal-poor stars (VMP; [Fe/H]~) in the solar neighbourhood (within kpc), selected to be on planar or…

astro-ph.GA2024★ 5 cited

The Pristine Survey -- XXVII. Journey to the Galactic outskirts -- Mapping the outer halo red giant stars down to the very metal-poor end

Akshara Viswanathan, Amanda Byström, Else Starkenburg +14

Context: In the context of Galactic archaeology, the outer halo remains relatively unexplored with respect to its metallicity distribution, merger debris, and the abundance of know…

astro-ph.GA2024

HR-GO I: Comprehensive NLTE abundance analysis of the Cetus stream

T. M. Sitnova, Z. Yuan, T. Matsuno +8

Dwarf galaxy streams encode vast amounts of information essential to understanding early galaxy formation and nucleosynthesis channels. Due to the variation in the timescales of st…

astro-ph.GA2024

The Pristine survey XXIV: The Galactic underdogs -- Dynamic tales of a Milky Way metal-poor population

Isaure González Rivera de La Vernhe, Vanessa Hill, Georges Kordopatis +12

Through the chemodynamical characterisation of metal-poor stars, one can efficiently probe the early history of the Milky Way. We aim at decontaminating a sample of 3M giant…

astro-ph.GA2024★ 11 cited

The Pristine Inner Galaxy Survey (PIGS) IX. The largest detailed chemical analysis of very metal-poor stars in the Sagittarius dwarf galaxy

Federico Sestito, Sara Vitali, Paula Jofre +16

The most metal-poor stars provide valuable insights into the early chemical enrichment history of a system, carrying the chemical imprints of the first generations of supernovae. T…

astro-ph.GA2024★ 12 cited

The Pristine Inner Galaxy Survey (PIGS) X. Probing the early chemical evolution of the Sagittarius dwarf galaxy with carbon abundances

Federico Sestito, Anke Ardern-Arentsen, Sara Vitali +6

We aim to constrain the chemo-dynamical properties of the Sagittarius (Sgr) dwarf galaxy using carbon abundances. Our sample from the \textit{Pristine} Inner Galaxy Survey (PIGS) i…

astro-ph.GA2024★ 11 cited

The Pristine survey: XXV. The very metal-poor Galaxy: Chemodynamics through the follow-up of the Pristine-Gaia synthetic catalogue

Akshara Viswanathan, Zhen Yuan, Anke Ardern-Arentsen +27

The Pristine-\textit{Gaia} synthetic catalogue provides reliable photometric metallicities for 30 million FGK stars using the Pristine survey model and Gaia XP spectra. We pe…

astro-ph.GA2024

GHOST Commissioning Science Results III: Characterizing an iron-poor damped Lyman system

Trystyn A. M. Berg, Christian R. Hayes, Stefano Cristiani +20

The Gemini High-resolution Optical SpecTrograph (GHOST) is a new echelle spectrograph available on the Gemini-South telescope as of Semester 2024A. We present the first high resolu…

astro-ph.GA2024★ 15 cited

On the metal-poor edge of the Milky Way "thin disc"

Emma Fernández-Alvar, Georges Kordopatis, Vanessa Hill +9

The emergence of the disc in our Galaxy and the relation of the thick and thin disc formation and evolution is still a matter of debate. The chemo-dynamical characterization of dis…