papers

Publications (111)

astro-ph.GA2022

The Pristine Inner Galaxy Survey (PIGS) V: a chemo-dynamical investigation of the early assembly of the Milky Way with the most metal-poor stars in the bulge

Federico Sestito, Kim A. Venn, Anke Arentsen +13

The investigation of the metal-poor tail in the Galactic bulge provides unique information on the early Milky Way assembly and evolution. A chemo-dynamical analysis of 17 very meta…

astro-ph.GA2020

The Pristine Dwarf-Galaxy survey -- III. Revealing the nature of the Milky Way globular cluster Sagittarius II

Nicolas Longeard, Nicolas Martin, Rodrigo Ibata +13

We present a new spectroscopic study of the faint Milky Way satellite Sagittarius II. Using multi-object spectroscopy from the Fibre Large Array Multi Element Spectrograph, we supp…

astro-ph.SR2014

Binarity in Carbon-Enhanced Metal-Poor stars

Else Starkenburg, Matthew D. Shetrone, Alan W. McConnachie +1

A substantial fraction of the lowest metallicity stars show very high enhancements in carbon. It is debated whether these enhancements reflect the stars' birth composition, or if t…

astro-ph.GA2021

CAPOS: The bulge Cluster APOgee Survey I. Overview and initial ASPCAP results

Doug Geisler, Sandro Villanova, Julia E. O'Connell +39

Context. Bulge globular clusters (BGCs) are exceptional tracers of the formation and chemodynamical evolution of this oldest Galactic component. However, until now, observational d…

astro-ph.IM2016

The Detailed Science Case for the Maunakea Spectroscopic Explorer: the Composition and Dynamics of the Faint Universe

Alan McConnachie, Carine Babusiaux, Michael Balogh +173

MSE is an 11.25m aperture observatory with a 1.5 square degree field of view that will be fully dedicated to multi-object spectroscopy. More than 3200 fibres will feed spectrograph…

astro-ph.GA2020

Exploring the origin of low-metallicity stars in Milky Way-like galaxies with the NIHAO-UHD simulations

Federico Sestito, Tobias Buck, Else Starkenburg +6

The kinematics of the most metal-poor stars provide a window into the early formation and accretion history of the Milky Way. Here, we use 5~high-resolution cosmological zoom-in si…

astro-ph.CO2012

Cleaning spectroscopic samples of stars in nearby dwarf galaxies: The use of the nIR MgI line to weed out Milky Way contaminants

Giuseppina Battaglia, Else Starkenburg

Dwarf galaxies provide insights on the processes of star formation and chemical enrichment at the low end of the galaxy mass function, as well as on the clustering of dark matter o…

astro-ph.GA2024

Reassessing the proper motions of M31/M33 with Gaia DR3. Unraveling systematic uncertainties

Samuel Rusterucci, Nicolas F. Martin, Else Starkenburg +1

We provide an updated inference of the proper motion of M31 using the Gaia DR3 proper motions of bright stars from the disc of M31. By refining the motion of the quasar reference f…

astro-ph.GA2020

The Pristine Inner Galaxy Survey (PIGS) II: Uncovering the most metal-poor populations in the inner Milky Way

Anke Arentsen, Else Starkenburg, Nicolas F. Martin +19

Metal-poor stars are important tools for tracing the early history of the Milky Way, and for learning about the first generations of stars. Simulations suggest that the oldest meta…

astro-ph.GA2023

The Pristine survey -- XX: GTC follow-up observations of extremely metal-poor stars identified from Pristine and LAMOST

Anke Arentsen, David S. Aguado, Federico Sestito +5

Ultra metal-poor stars ([Fe/H] < -4.0) are very rare, and finding them is a challenging task. Both narrow-band photometry and low-resolution spectroscopy have been useful tools for…

astro-ph.GA2013

The extremely low-metallicity tail of the Sculptor dwarf spheroidal galaxy

Else Starkenburg, Vanessa Hill, Eline Tolstoy +10

We present abundances for seven stars in the (extremely) low-metallicity tail of the Sculptor dwarf spheroidal galaxy, from spectra taken with X-shooter on the ESO VLT. Targets wer…

astro-ph.GA2021

The Pristine survey -- XII: Gemini-GRACES chemo-dynamical study of newly discovered extremely metal-poor stars in the Galaxy

Collin L. Kielty, Kim A. Venn, Federico Sestito +16

High-resolution optical spectra of 30 metal-poor stars selected from the \Pristine\ survey are presented, based on observations taken with the Gemini Observatory GRACES spectrograp…

astro-ph.GA2025

Gaia's brightest very metal-poor (VMP) stars. Metallicity catalogue of a thousand VMP stars from Gaia's radial velocity spectrometer spectra

Akshara Viswanathan, Else Starkenburg, Tadafumi Matsuno +10

Context. Gaia DR3 has offered the scientific community a remarkable dataset of approximately one million spectra acquired with the Radial Velocity Spectrometer (RVS) in the Calcium…

astro-ph.GA2021

The Pristine Inner Galaxy Survey (PIGS) III: carbon-enhanced metal-poor stars in the bulge

Anke Arentsen, Else Starkenburg, David S. Aguado +15

The most metal-deficient stars hold important clues about the early build-up and chemical evolution of the Milky Way, and carbon-enhanced metal-poor (CEMP) stars are of special int…

astro-ph.GA2009

Mapping the Galactic Halo VIII: Quantifying substructure

Else Starkenburg, Amina Helmi, Heather L. Morrison +11

We have measured the amount of kinematic substructure in the Galactic halo using the final data set from the Spaghetti project, a pencil-beam high latitude sky survey. Our sample c…

astro-ph.SR2026

The Carbon-Dependent Binary Frequency of CEMP-no Stars

John D. Dixon, Terese T. Hansen, Jennifer Marshall +15

The authors monitored radial velocities of 30 CEMP-no stars and combined these data with literature to assess binary frequencies, finding that high‑carbon CEMP-no stars have a sign…

#metal-poor stars#cemp-no stars#binary fraction#radial velocity monitoring
astro-ph.GA2024

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…

astro-ph.GA2014

Bulge mass is king: The dominant role of the bulge in determining the fraction of passive galaxies in the Sloan Digital Sky Survey

Asa F. L. Bluck, J. Trevor Mendel, Sara L. Ellison +4

We investigate the origin of galaxy bimodality by quantifying the relative role of intrinsic and environmental drivers to the cessation (or `quenching') of star formation in over h…

astro-ph.GA2025

Hidden deep in the halo: selection of a reduced proper motion halo catalogue and mining retrograde streams in the velocity space

Akshara Viswanathan, Else Starkenburg, Helmer H. Koppelman +3

The Milky Way halo is one of the few galactic haloes that provides a unique insight into galaxy formation by resolved stellar populations. Here, we present a catalogue of 47…

astro-ph.GA2015

The SEGUE K Giant Survey. III. Quantifying Galactic Halo Substructure

William Janesh, Heather L. Morrison, Zhibo Ma +9

We statistically quantify the amount of substructure in the Milky Way stellar halo using a sample of 4568 halo K giant stars at Galactocentric distances ranging over 5-125 kpc. The…

astro-ph.CO2013

Galaxy Pairs in the Local Group

Azadeh Fattahi, Julio F. Navarro, Else Starkenburg +2

Current models of galaxy formation predict that galaxy pairs of comparable magnitudes should become increasingly rare with decreasing luminosity. This seems at odds with the relati…

astro-ph.GA2014

The first carbon-enhanced metal-poor star found in the Sculptor dwarf spheroidal

Asa Skuladottir, Eline Tolstoy, Stefania Salvadori +4

The origin of carbon-enhanced metal-poor (CEMP) stars and their possible connection with the chemical elements produced by the first stellar generation is still highly debated. In…

astro-ph.GA2018

A-type stars in the Canada-France Imaging Survey I. The stellar halo of the Milky Way traced to large radius by blue horizontal branch stars

Guillaume F. Thomas, Alan W. McConnachie, Rodrigo A. Ibata +14

We present the stellar density profile of the outer halo of the Galaxy traced over a range of Galactocentric radii from kpc by blue horizontal branch (BHB) stars…

astro-ph.SR2018

The R-Process Alliance: Spectroscopic Follow-up of Low-Metallicity Star Candidates from the Best & Brightest Survey

Vinicius M. Placco, Rafael M. Santucci, Timothy C. Beers +17

We present results from an observing campaign to identify low-metallicity stars in the Best & Brightest Survey. From medium-resolution (R ~ 1, 200 - 2, 000) spectroscopy of 857 can…

astro-ph.CO2012

Not too big, not too small: the dark halos of the dwarf spheroidals in the Milky Way

Carlos A. Vera-Ciro, Amina Helmi, Else Starkenburg +1

We present a new analysis of the Aquarius simulations done in combination with a semi-analytic galaxy formation model. Our goal is to establish whether the subhalos present in LCDM…

astro-ph.GA2023

The Pristine Dwarf-Galaxy survey -- V. The edges of the dwarf galaxy Hercules

Nicolas Longeard, Pascale Jablonka, Giuseppina Battaglia +6

We present a new spectroscopic study of the dwarf galaxy Hercules (d ~ 132 kpc) with data from the Anglo-Australian Telescope and its AAOmega spectrograph together with the Two Deg…

astro-ph.GA2022

On the inconsistency of [C/Fe] abundances and the fractions of carbon-enhanced metal-poor stars among various stellar surveys

Anke Arentsen, Vinicius M. Placco, Young Sun Lee +4

Carbon-enhanced metal-poor (CEMP) stars are a unique resource for Galactic archaeology because they probe the properties of the First Stars, early chemical evolution and binary int…

astro-ph.GA2019

The Canada-France Imaging Survey: Reconstructing the Milky Way Star Formation History from its White Dwarf Population

Nicholas J. Fantin, Patrick Côté, Alan W. McConnachie +15

As the remnants of stars with initial masses 8 M, white dwarfs contain valuable information on the formation histories of stellar populations. In this paper, w…

astro-ph.GA2025

A test of Ca ii H & K photometry for isolating massive globular clusters below the metallicity floor

Bas van Heumen, William E. Harris, Søren S. Larsen +1

The serendipitous discovery of the M31 globular cluster (GC) EXT8 has presented a significant challenge to current theories for GC formation. By finding other GCs similar to EXT8,…

astro-ph.GA2023

Could very low-metallicity stars with rotation-dominated orbits have been shepherded by the bar?

Zhen Yuan, Chengdong Li, Nicolas F. Martin +11

The most metal-poor stars (e.g. [Fe/H] ) are the ancient fossils from the early assembly epoch of our Galaxy, very likely before the formation of the thick disc. Recent s…

astro-ph.GA2022

The Pristine Inner Galaxy Survey (PIGS) VI: Different vertical distributions between two DIBs at 442.8 nm and 862.1 nm

He Zhao, Mathias Schultheis, Anke Arentsen +8

Although diffuse interstellar bands (DIBs) were discovered over 100 years ago, for most of them, their origins are still unknown. Investigation on the correlations between differen…

astro-ph.GA2013

The Comparative Chemical Evolution of an Isolated Dwarf Galaxy: A VLT and Keck Spectroscopic Survey of WLM

Ryan Leaman, Kim A. Venn, Alyson M. Brooks +8

Building on our previous spectroscopic and photometric analysis of the isolated Local Group dwarf irregular (dIrr) galaxy WLM, we present a comparison of the metallicities of its R…

astro-ph.GA2016

The impact of galactic properties and environment on the quenching of central and satellite galaxies: A comparison between SDSS, Illustris and L-Galaxies

Asa F. L. Bluck, J. Trevor Mendel, Sara L. Ellison +7

We quantify the impact that a variety of galactic and environmental properties have on the quenching of star formation. We collate a sample of 400,000 central and 100…

astro-ph.GA2018

Semi-analytic modelling of the europium production by neutron star mergers in the halo of the Milky Way

Pim van Oirschot, Gijs Nelemans, Onno Pols +1

Neutron star mergers (NSM) are likely to be the main production sites for the rapid (r-) neutron capture process elements. We study the r-process enrichment of the stellar halo of…

astro-ph.GA2017

The "Building Blocks" of Stellar Halos

Kyle A. Oman, Else Starkenburg, Julio F. Navarro

The stellar halos of galaxies encode their accretion histories. In particular, the median metallicity of a halo is determined primarily by the mass of the most massive accreted obj…

astro-ph.GA2024

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.GA2019

The Pristine Inner Galaxy Survey (PIGS) I: Tracing the kinematics of metal-poor stars in the Galactic bulge

Anke Arentsen, Else Starkenburg, Nicolas F. Martin +20

Our Galaxy is known to contain a central boxy/peanut-shaped bulge, yet the importance of a classical, pressure-supported component within the central part of the Milky Way is still…

astro-ph.GA2024

A slow spin to win -- the gradual evolution of the proto-Galaxy to the old disc

Akshara Viswanathan, Danny Horta, Adrian M. Price-Whelan +1

Observational studies are identifying stars thought to be remnants from the earliest stages of the hierarchical mass assembly of the Milky Way, referred to as the proto-Galaxy. We…

astro-ph.GA2014

Chemical enrichment in very low-metallicity environments: Bootes I

Donatella Romano, Michele Bellazzini, Else Starkenburg +1

We present different chemical evolution models for the ultrafaint dwarf galaxy Bootes I. We either assume that the galaxy accretes its mass through smooth infall of gas of primordi…

astro-ph.GA2025

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.GA2018

Pristine Dwarf-Galaxy Survey I: A detailed photometric and spectroscopic study of the very metal-poor Draco II satellite

Nicolas Longeard, Nicolas Martin, Else Starkenburg +17

We present a detailed study of the faint Milky Way satellite Draco II (Dra II) from deep CFHT/MegaCam broadband and photometry and narrow-band metallicity-sensitive CaHK ob…

astro-ph.IM2019

The Detailed Science Case for the Maunakea Spectroscopic Explorer, 2019 edition

The MSE Science Team, Carine Babusiaux, Maria Bergemann +258

(Abridged) The Maunakea Spectroscopic Explorer (MSE) is an end-to-end science platform for the design, execution and scientific exploitation of spectroscopic surveys. It will unvei…

astro-ph.GA2019

The Pristine Dwarf-Galaxy survey - II. In-depth observational study of the faint Milky Way satellite Sagittarius II

Nicolas Longeard, Nicolas Martin, Else Starkenburg +11

We present an extensive study of the Sagittarius II (Sgr II) stellar system using MegaCam g and i photometry, narrow-band, metallicity-sensitive Calcium H&K doublet photometry, aug…

astro-ph.GA2024

ACACIAS I: Element abundance labels for 192 stars in the dwarf galaxy NGC 6822

Melissa K. Ness, J. Trevor Mendel, Sven Buder +8

The element abundances of local group galaxies connect enrichment mechanisms to galactic properties and serve to contextualise the Milky Way's abundance distributions. Individual s…

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.GA2017

A unified model for age-velocity dispersion relations in Local Group galaxies: Disentangling ISM turbulence and latent dynamical heating

Ryan Leaman, J. Trevor Mendel, Emily Wisnioski +9

We analyze age-velocity dispersion relations (AVRs) from kinematics of individual stars in eight Local Group galaxies ranging in mass from Carina () to M31 ($M_{…

astro-ph.IM2016

A concise overview of the Maunakea Spectroscopic Explorer

Alan W. McConnachie, Carine Babusiaux, Michael Balogh +19

This short document is intended as a companion and introduction to the Detailed Science Case (DSC) for the Maunakea Spectroscopic Explorer. It provides a concise summary of the ess…

astro-ph.GA2016

Building Blocks of the Milky Way's Accreted Spheroid

Pim van Oirschot, Else Starkenburg, Amina Helmi +1

In the CDM model of structure formation, a stellar spheroid grows by the assembly of smaller galaxies, the so-called building blocks. Combining the Munich-Groningen semi-analyt…

astro-ph.GA2013

The Orbital Ellipticity of Satellite Galaxies and the Mass of the Milky Way

Christopher Barber, Else Starkenburg, Julio Navarro +2

We use simulations of Milky Way-sized dark matter haloes from the Aquarius Project to investigate the orbits of substructure haloes likely, according to a semi-analytic galaxy form…

astro-ph.GA2024

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.GA2023

A 3D view of dwarf galaxies with Gaia and VLT/FLAMES I. The Sculptor dwarf spheroidal

Eline Tolstoy, Ása Skúladóttir, Giuseppina Battaglia +12

We present a new homogeneous survey of VLT/FLAMES LR8 line-of-sight radial velocities (vlos) for 1604 resolved red giant branch stars in the Sculptor dwarf spheroidal galaxy. In ad…

astro-ph.GA2024

Stellar Metallicities and Gradients in the Isolated, Quenched Low-Mass Galaxy Tucana

Sal Wanying Fu, Daniel R. Weisz, Else Starkenburg +10

We measure the metallicities of 374 red giant branch (RGB) stars in the isolated, quenched dwarf galaxy Tucana using Hubble Space Telescope (HST) narrow-band (F395N) Calcium H & K…

astro-ph.GA2013

Chemical evolution of Local Group dwarf galaxies in a cosmological context -- I. A new modelling approach and its application to the Sculptor dwarf spheroidal galaxy

Donatella Romano, Else Starkenburg

We present a new approach for chemical evolution modelling, specifically designed to investigate the chemical properties of dwarf galaxies in a full cosmological framework. In part…

astro-ph.GA2026

Temperature asymmetry in the Milky Way's hot circumgalactic medium induced by the Magellanic Clouds

Alexandru Oprea, Filippo Fraternali, Else Starkenburg +2

The Milky Way is surrounded by a hot diffuse circumgalactic medium (CGM) with temperatures of millions of degrees. Recent X-ray observations with the eROSITA satellite discovered a…

astro-ph.GA2022

The Complexity of the Cetus Stream Unveiled from the Fusion of STREAMFINDER and StarGO

Zhen Yuan, Khyati Malhan, Federico Sestito +16

We combine the power of two stream-searching tools, STREAMFINDER and StarGO applied to the Gaia EDR3 data, to detect stellar debris belonging to the Cetus stream system that forms…

astro-ph.GA2018

Phlegethon, a nearby -long retrograde stellar stream

Rodrigo A. Ibata, Khyati Malhan, Nicolas F. Martin +1

We report the discovery of a long stellar stream in Gaia DR2 catalog, found using the new STREAMFINDER algorithm. The structure is probably the remnant of a now fully disrup…

astro-ph.IM2023

The wide-field, multiplexed, spectroscopic facility WEAVE: Survey design, overview, and simulated implementation

Shoko Jin, Scott C. Trager, Gavin B. Dalton +212

WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree…

astro-ph.GA2021

The Stars of the HETDEX Survey. I. Radial Velocities and Metal-Poor Stars from Low-Resolution Stellar Spectra

Keith Hawkins, Greg Zeimann, Chris Sneden +18

The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is an unbiased, massively multiplexed spectroscopic survey, designed to measure the expansion history of the universe thr…

astro-ph.GA2018

White dwarfs in the building blocks of the Galactic spheroid

Pim van Oirschot, Gijs Nelemans, Else Starkenburg +3

The galactic halo likely grew over time in part by assembling smaller galaxies, the so-called building blocks. We investigate if the properties of these building blocks are reflect…

astro-ph.SR2010

The NIR Ca II triplet at low metallicity - Searching for extremely low-metallicity stars in classical dwarf galaxies

Else Starkenburg, Vanessa Hill, Eline Tolstoy +9

The NIR Ca II triplet absorption lines have proven to be an important tool for quantitative spectroscopy of individual red giant branch stars in the Local Group, providing a better…

astro-ph.GA2025

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.GA2023

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

Sal Wanying Fu, Daniel R. Weisz, Else Starkenburg +10

We present uniformly measured stellar metallicities for 463 stars in 13 Milky Way (MW) ultra-faint dwarf galaxies (UFDs; to ) using narrowband CaHK (F395N) imagi…

astro-ph.GA2019

The Pristine survey -- VII. A cleaner view of the Galactic outer halo using blue horizontal branch stars

Else Starkenburg, Kris Youakim, Nicolas Martin +11

We use the Pristine survey CaHK narrow-band photometry, combined with the SDSS ugr photometry, to provide a cleaner sample of blue horizontal branch stars in the Galactic halo out…

astro-ph.GA2024

The Pristine Inner Galaxy Survey (PIGS) VIII: Characterising the orbital properties of the ancient, very metal-poor inner Milky Way

Anke Ardern-Arentsen, Giacomo Monari, Anna B. A. Queiroz +19

The oldest stars in the Milky Way (born in the first few billion years) are expected to have a high density in the inner few kpc, spatially overlapping with the Galactic bulge. We…

astro-ph.GA2024

Stellar Metallicities and Gradients in the Faint M31 Satellites Andromeda XVI and Andromeda XXVIII

Sal Wanying Fu, Daniel R. Weisz, Else Starkenburg +11

We present stellar metallicity measurements in two faint M31 dwarf galaxies, Andromeda XVI () and Andromeda XXVIII () derived using metallicity-se…

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.GA2022

The Pristine Dwarf-Galaxy survey -- IV. Probing the outskirts of the dwarf galaxy Boötes I

Nicolas Longeard, Pascale Jablonka, Anke Arentsen +12

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 Fi…

astro-ph.GA2019

Tracing the formation of the Milky Way through ultra metal-poor stars

Federico Sestito, Nicolas Longeard, Nicolas F. Martin +11

We use Gaia DR2 astrometric and photometric data, published radial velocities and MESA models to infer distances, orbits, surface gravities, and effective temperatures for all ultr…

astro-ph.SR2018

The Pristine Survey IV: Approaching the Galactic metallicity floor with the discovery of an ultra metal-poor star

Else Starkenburg, David S. Aguado, Piercarlo Bonifacio +22

The early Universe presented a star formation environment that was almost devoid of heavy elements. The lowest metallicity stars thus provide a unique window into the earliest Gala…

astro-ph.GA2025

C-19 and Hot, Wide, Star Streams

Raymond G. Carlberg, Rodrigo Ibata, Nicolas F. Martin +4

The C-19 star stream has the abundance characteristics of an unusually metal poor globular cluster but kinematically is uncharacteristically hot and wide for a cluster stream, havi…

astro-ph.GA2022

The Pristine survey XVIII: C-19: Tidal debris of a dark matter-dominated globular cluster?

Raphaël Errani, Julio F. Navarro, Rodrigo Ibata +12

The recently discovered C-19 stellar stream is a collection of kinematically associated metal-poor stars in the halo of the Milky Way lacking an obvious progenitor. The stream span…

astro-ph.GA2022

The Pristine survey -- XVII. The C-19 stream is dynamically hot and more extended than previously thought

Zhen Yuan, Nicolas F. Martin, Rodrigo A. Ibata +22

The C-19 stream is the most metal poor stellar system ever discovered, with a mean metallicity . Its low metallicity dispersion ( 0.18 a…

astro-ph.GA2026

Tracing the very early disruption of the Sagittarius dwarf galaxy in the distant Milky Way halo

Manuel Bayer, Else Starkenburg, Akshara Viswanathan +3

Current models predict that at distances beyond 80 kpc in the Milky Way halo, we can find the earliest escaped stars from the merging Sagittarius dwarf galaxy. However, observation…

astro-ph.GA2022

The Pristine Inner Galaxy Survey (PIGS) IV: A photometric metallicity analysis of the Sagittarius dwarf spheroidal galaxy

Sara Vitali, Anke Arentsen, Else Starkenburg +15

We present a comprehensive metallicity analysis of the Sagittarius dwarf spheroidal galaxy (Sgr dSph) using photometry. We base our member selection on EDR3…

astro-ph.GA2022

Stellar kinematics of dwarf galaxies from multi-epoch spectroscopy: application to Triangulum II

Rachel Buttry, Andrew B. Pace, Sergey E. Koposov +9

We present new MMT/Hectochelle spectroscopic measurements for 257 stars observed along the line of sight to the ultra-faint dwarf galaxy Triangulum II. Combining with results from…

astro-ph.GA2021

Zero-metallicity hypernova uncovered by an ultra metal-poor star in the Sculptor dwarf spheroidal galaxy

Ása Skúladóttir, Stefania Salvadori, Anish M. Amarsi +9

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 n…

astro-ph.SR2023

Improving metallicity estimates for very metal-poor stars in the Gaia DR3 GSP-Spec catalog

Tadafumi Matsuno, Else Starkenburg, Eduardo Balbinot +1

The Gaia DR3 GSP-Spec parameters, including metallicity, for VMP stars suffer from parameter degeneracy due to a lack of information in their spectra. Furthermore, the recommended…

astro-ph.GA2022

The Pristine survey -- XVI. The metallicity of 26 stellar streams around the Milky Way detected with the STREAMFINDER in Gaia EDR3

Nicolas F. Martin, Rodrigo A. Ibata, Else Starkenburg +21

We use the photometric metallicities provided by the panoramic Pristine survey to study the veracity and derive the metallicities of the numerous stellar streams found by the appli…

astro-ph.GA2018

A-type stars in the Canada-France Imaging Survey II. Tracing the height of the disc at large distances with Blue Stragglers

Guillaume F. Thomas, Chervin F. P. Laporte, Alan W. McConnachie +7

We present the kinematics of Blue Straggler (BS) stars identified in the Canada-France-Imaging-Survey (CFIS), covering 4000 deg on the sky in the -band. The BS sample, chara…

astro-ph.GA2024

The Pristine survey -- XXIII. Data Release 1 and an all-sky metallicity catalogue based on Gaia DR3 BP/RP spectro-photometry

Nicolas F. Martin, Else Starkenburg, Zhen Yuan +38

We used the spectro-photometric information of ~219 million stars from Gaia's DR3 to calculate synthetic, narrow-band, metallicity-sensitive CaHK magnitudes that mimic the observat…

astro-ph.GA2022

A stellar stream remnant of a globular cluster below the metallicity floor

Nicolas F. Martin, Kim A. Venn, David S. Aguado +23

Stellar ejecta gradually enrich the gas out of which subsequent stars form, making the least chemically enriched stellar systems direct fossils of structures formed in the early un…

astro-ph.SR2018

Binarity among CEMP-no stars: an indication of multiple formation pathways?

Anke Arentsen, Else Starkenburg, Matthew D. Shetrone +3

Carbon-enhanced metal-poor (CEMP) stars comprise a large percentage of stars at the lowest metallicities. The stars in the CEMP-no subcategory do not show any s-process enhancement…

astro-ph.GA2019

The Pristine survey X: a large population of low-metallicity stars permeates the Galactic disk

Federico Sestito, Nicolas F. Martin, Else Starkenburg +26

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 st…

astro-ph.GA2020

The hidden past of M92: Detection and characterization of a newly formed 17° long stellar stream using the Canada-France Imaging Survey

Guillaume F. Thomas, Jaclyn Jensen, Alan McConnachie +17

We present an analysis of the structure, kinematics and orbit of a newly found stellar stream emanating from the globular cluster M92 (NGC 6341). This stream was discovered in an i…

astro-ph.GA2023

Probing the early Milky Way with GHOST spectra of an extremely metal-poor star in the Galactic disk

Anya Dovgal, Kim A. Venn, Federico Sestito +31

Pristine_183.6849+04.8619 (P1836849) is an extremely metal-poor ([Fe/H]) star on a prograde orbit confined to the Galactic disk. Such stars are rare and may have their…

astro-ph.GA2021

Uncovering fossils of the distant Milky Way with UNIONS: NGC 5466 and its stellar stream

Jaclyn Jensen, Guillaume Thomas, Alan W. McConnachie +9

We examine the spatial clustering of blue horizontal branch (BHB) stars from the -band of the Canada-France Imaging Survey (CFIS, a component of the Ultraviolet Near-In…

astro-ph.GA2017

The Canada-France Imaging Survey: First results from the u-band component

Rodrigo Ibata, Alan McConnachie, Jean-Charles Cuillandre +41

The Canada-France Imaging Survey (CFIS) will map the northern high Galactic latitude sky in the -band ("CFIS-u", 10,000) and in the -band ("CFIS-r", 5,000$\,…

astro-ph.SR2014

Searching for Dust around Hyper Metal-Poor Stars

Kim A. Venn, Thomas H. Puzia, Mike Divell +3

We examine the mid-infrared fluxes and spectral energy distributions for metal-poor stars with iron abundances [Fe/H] , as well as two CEMP-no stars, to eliminate the p…

astro-ph.GA2024

GHOST Commissioning Science Results II: a very metal-poor star witnessing the early Galactic assembly

Federico Sestito, Christian R. Hayes, Kim A. Venn +25

This study focuses on Pristine (hereafter P180956, ), a star selected from the Pristine Inner Galaxy Survey (PIGS), and followed-up…

astro-ph.GA2013

The satellites of the Milky Way - Insights from semi-analytic modelling in a LambdaCDM cosmology

Else Starkenburg, Amina Helmi, Gabriella De Lucia +7

We combine the six high-resolution Aquarius dark matter simulations with a semi-analytic galaxy formation model to investigate the properties of the satellites of Milky Way-like ga…

astro-ph.GA2014

Why do galaxies stop forming stars? I. The passive fraction - black hole mass relation for central galaxies

Asa F. L. Bluck, Sara L. Ellison, David R. Patton +5

We derive the dependence of the fraction of passive central galaxies on the mass of their supermassive black holes for a sample of over 400,000 SDSS galaxies at z < 0.2. Our large…

astro-ph.GA2023

Swarming in stellar streams: Unveiling the structure of the Jhelum stream with ant colony-inspired computation

Petra Awad, Marco Canducci, Eduardo Balbinot +8

The halo of the Milky Way galaxy hosts multiple dynamically coherent substructures known as stellar streams that are remnants of tidally disrupted systems such as globular clusters…

astro-ph.GA2021

Metallicity Distribution Function of the Eridanus~II Ultra-Faint Dwarf Galaxy from Hubble Space Telescope Narrow-band Imaging

Sal Wanying Fu, Daniel R. Weisz, Else Starkenburg +9

We use deep narrowband Ca H&K () imaging taken with the Hubble Space Telescope (HST) to construct the metallicity distribution function (MDF) of Local Group (LG) ultra-faint…

astro-ph.SR2019

Pristine IX: CFHT ESPaDOnS Spectroscopic Analysis of 115 Bright Metal-Poor Candidate Stars

Kim Venn, Collin Kielty, Federico Sestito +18

A chemo-dynamical analysis of 115 metal-poor candidate stars selected from the narrow-band Pristine photometric survey is presented based on CFHT high-resolution ESPaDoNS spectrosc…

astro-ph.GA2014

Galactic Tides and the Shape and Orientation of Dwarf Galaxy Satellites

Christopher Barber, Else Starkenburg, Julio F. Navarro +1

We use cosmological N-body simulations from the Aquarius Project to study the tidal effects of a dark matter halo on the shape and orientation of its substructure. Although tides a…

astro-ph.GA2025

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.GA2019

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

David S. Aguado, Kris Youakim, Jonay I. González Hernández +27

We present the results of a 3-year long, medium-resolution spectroscopic campaign aimed at identifying very metal-poor stars from candidates selected with the CaHK, metallicity-sen…

astro-ph.GA2019

VLT/FLAMES high-resolution chemical abundances in Sculptor: a textbook dwarf spheroidal galaxy

Vanessa Hill, Ása Skúladóttir, Eline Tolstoy +12

We present detailed chemical abundances for 99 red-giant branch stars in the centre of the Sculptor dwarf spheroidal galaxy, obtained from high-resolution VLT/FLAMES spectroscopy.…

astro-ph.GA2024

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.GA2017

The Pristine survey I: Mining the Galaxy for the most metal-poor stars

Else Starkenburg, Nicolas Martin, Kris Youakim +22

We present the Pristine survey, a new narrow-band photometric survey focused on the metallicity-sensitive Ca H & K lines and conducted in the northern hemisphere with the wide-fiel…