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

Abstract

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 addition, we provide reliable Ca II triplet metallicities, [Fe/H], for 1339 of these stars. From this combination of new observations (2257 individual spectra) with ESO archival data (2389 spectra), we obtain the largest and most complete sample of vlos and [Fe/H] measurements for individual stars in any dwarf galaxy. Our sample includes VLT/FLAMES LR8 spectra for 55% of the red giant branch stars at G $<20$ from Gaia DR3, and $>70$% of the brightest stars, G $<18.75$. Our spectroscopic velocities are combined with Gaia DR3 proper motions and parallax measurements for a new and more precise membership analysis. We look again at the global characteristics of Sculptor, deriving a mean metallicity of $⟨$[Fe/H]$⟩=-1.82\pm 0.45$ and a mean line-of-sight velocity of $⟨$vlos$⟩=+111.2\pm 0.25$km/s. There is a clear metallicity gradient in Sculptor, -0.7deg/dex, with the most metal-rich population being the most centrally concentrated. Furthermore, the most metal-poor population in Sculptor, [Fe/H]$<-2.5$, appears to show kinematic properties distinct from the rest of the stellar population. Finally, we combine our results with the exquisite Gaia DR3 multi-colour photometry to further investigate the colour-magnitude diagram of the resolved stellar population in Sculptor. Our detailed analysis shows a similar global picture as previous studies, but with much more precise detail, revealing that Sculptor has more complex properties than previously thought. This survey emphasises the role of the stellar spectroscopy technique and this galaxy as a benchmark system for modelling galaxy formation and evolution on small scales.

arXiv commentA&A, in press

References in corpus (87)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• Gaia Data Release 3: Summary of the content and survey properties
• The SIMBAD astronomical database
• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy
• Gaia Early Data Release 3: Parallax bias versus magnitude, colour, and position
• Gaia Early Data Release 3: Photometric content and validation
• Gaia Data Release 2: Photometric content and validation
• Automated data reduction workflows for astronomy
• A Method for Measuring (Slopes of) the Mass Profiles of Dwarf Spheroidal Galaxies
• Gaia Data Release 2: Kinematics of globular clusters and dwarf galaxies around the Milky Way
• Numerical Methods of Star Formation History Measurement and Applications to Seven Dwarf Spheroidals
• VLT/UVES Abundances in Four Nearby Dwarf Spheroidal Galaxies: I. Nucleosynthesis and Abundance Ratios
• The Star Formation Histories of Local Group Dwarf Galaxies I. Hubble Space Telescope / Wide Field Planetary Camera 2 Observations
• Gaia Early Data Release 3 -- Catalogue validation
• Two distinct ancient components in the Sculptor Dwarf Spheroidal Galaxy: First Results from DART
• The Updated BaSTI Stellar Evolution Models and Isochrones: I. Solar Scaled Calculations
• The kinematic status and mass content of the Sculptor dwarf spheroidal galaxy
• Disruption of Dark Matter Substructure: Fact or Fiction?
• Evolution of Thermally Pulsing Asymptotic Giant Branch Stars I. The COLIBRI Code
• The Role of Stellar Feedback and Dark Matter in the Evolution of Dwarf Galaxies
• Stellar Velocities in the Carina, Fornax, Sculptor and Sextans dSph Galaxies: Data from the Magellan/MMFS Survey
• The Pristine survey I: Mining the Galaxy for the most metal-poor stars
• VLT/UVES Abundances in Four Nearby Dwarf Spheroidal Galaxies: II. Implications for Understanding Galaxy Evolution
• Population Gradients in Local Group Dwarf Spheroidals
• The NIR Ca II triplet at low metallicity - Searching for extremely low-metallicity stars in classical dwarf galaxies
• Analysis and calibration of CaII triplet spectroscopy of Red Giant Branch stars from VLT/FLAMES observations
• 'Sculptor'-ing the Galaxy? The Chemical Compositions of Red Giants in the Sculptor Dwarf Spheroidal Galaxy
• The updated BaSTI stellar evolution models and isochrones: II. alpha-enhanced calculations
• Multi-Element Abundance Measurements from Medium-Resolution Spectra. II. Catalog of Stars in Milky Way Dwarf Satellite Galaxies
• The Star Formation & Chemical Evolution History of the Sculptor Dwarf Spheroidal Galaxy
• Linking dwarf galaxies to halo building blocks with the most metal-poor star in Sculptor
• Extremely metal-poor stars in classical dwarf spheroidal galaxies: Fornax, Sculptor and Sextans
• The Predicted Metallicity Distribution of Stars in Dwarf Spheroidal Galaxies
• Multi-Element Abundance Measurements from Medium-Resolution Spectra. I. The Sculptor Dwarf Spheroidal Galaxy
• Gaia early DR3 systemic motions of Local Group dwarf galaxies and orbital properties with a massive Large Magellanic Cloud
• Gaia Proper Motions and Orbits of the Ultra-Faint Milky Way Satellites
• Ultra faint dwarfs: probing early cosmic star formation
• The mass and velocity anisotropy of the Carina, Fornax, Sculptor and Sextans dwarf spheroidal galaxies
• The Dynamical and Chemical Evolution of Dwarf Spheroidal Galaxies
• Using the Ca II Triplet to Trace Abundance Variations in Individual Red Giant Branch stars in Three Nearby Galaxies
• Pushing back the limits: detailed properties of dwarf galaxies in a LCDM universe
• VLT/FLAMES high-resolution chemical abundances in Sculptor: a textbook dwarf spheroidal galaxy
• The Near Infrared Ca II Triplet as Metallicity Indicator: II Extension to extremely metal-poor metallicity regimes
• A Virial Core in the Sculptor Dwarf Spheroidal Galaxy
• Carbon-enhanced metal-poor stars in dwarf galaxies
• Internal kinematics and dynamical models of dwarf spheroidal galaxies around the Milky Way
• The extremely low-metallicity tail of the Sculptor dwarf spheroidal galaxy
• Life and times of dwarf spheroidal galaxies
• Revised and new proper motions for confirmed and candidate Milky Way dwarf galaxies
• A New Culprit in the Second Parameter Problem in the Sculptor Dwarf Spheroidal Galaxy?
• Orbit-based dynamical models of the Sculptor dSph galaxy
• Model comparison of the dark matter profiles of Fornax, Sculptor, Carina and Sextans
• The first carbon-enhanced metal-poor star found in the Sculptor dwarf spheroidal
• An empirical model of the Gaia DR3 selection function
• The early days of the Sculptor dwarf spheroidal galaxy
• Carbon in Red Giants in Globular Clusters and Dwarf Spheroidal Galaxies
• The Chemical Evolution of Dwarf Spheroidal Galaxies: Dissecting the Inner Regions and their Stellar Populations
• Evidence for Sub-Chandrasekhar Type Ia Supernovae from Stellar Abundances in Dwarf Galaxies
• Variable Stars in Local Group Galaxies. I: Tracing the Early Chemical Enrichment and Radial Gradients in the Sculptor dSph with RR Lyrae Stars
• 3D motions in the Sculptor dwarf galaxy as a glimpse of a new era
• Chemical Signatures of the First Supernovae in the Sculptor Dwarf Spheroidal Galaxy
• A discrete chemo-dynamical model of the dwarf spheroidal galaxy Sculptor: mass profile, velocity anisotropy and internal rotation
• Deep Wide-Field Imaging down to the oldest Main Sequence Turnoffs in the Sculptor dwarf spheroidal galaxy
• Zero-metallicity hypernova uncovered by an ultra metal-poor star in the Sculptor dwarf spheroidal galaxy
• Dynamical models for the Sculptor dwarf spheroidal in a Lambda CDM universe
• Blue straggler stars in dwarf spheroidal galaxies II: Sculptor and Fornax
• Cosmological implications of dwarf spheroidal chemical evolution
• 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
• Zinc in the Sculptor dwarf spheroidal galaxy
• Detection of a population of carbon-enhanced metal-poor stars in the Sculptor dwarf spheroidal galaxy
• Cleaning spectroscopic samples of stars in nearby dwarf galaxies: The use of the nIR MgI line to weed out Milky Way contaminants
• The metal abundance distribution of the oldest stellar component in the Sculptor dwarf spheroidal galaxy
• The star formation history of the Sculptor dwarf spheroidal galaxy
• Simultaneous Constraints on the Star Formation History and Nucleosynthesis of Sculptor dSph
• Carbon and nitrogen abundances of individual stars in the Sculptor dwarf spheroidal galaxy
• Neutron-capture elements in dwarf galaxies II: Challenges for the s- and i-processes at low metallicity
• The stellar populations of high-redshift dwarf galaxies
• The effect of tides on the Sculptor dwarf spheroidal galaxy
• Proper Motion of Milky Way Dwarf Spheroidals from Line-of-Sight Velocities
• Sulphur in the Sculptor dwarf spheroidal galaxy - Including NLTE corrections
• MORGOTH: incorporating horizontal branch modelling into star formation history determinations
• The chemical connection between damped Lyman-α systems and Local Group dwarf galaxies
• Tidally induced velocity gradients in the Milky Way dwarf spheroidal satellites
• An investigation of C, N and Na abundances in red giant stars of the Sculptor dwarf spheroidal galaxy
• Near-infrared chemical abundances of stars in the Sculptor dwarf galaxy

Cited by in corpus (12)

• Tracing Pop III supernovae with extreme energies through the Sculptor dwarf spheroidal galaxy
• Magellan/M2FS and MMT/Hectochelle Spectroscopy of Dwarf Galaxies and Faint Star Clusters within the Galactic Halo
• Binary star population of the Sculptor dwarf galaxy
• The Pristine Inner Galaxy Survey (PIGS) X. Probing the early chemical evolution of the Sagittarius dwarf galaxy with carbon abundances
• The Pristine Inner Galaxy Survey (PIGS) IX. The largest detailed chemical analysis of very metal-poor stars in the Sagittarius dwarf galaxy
• Evidence of Gaia Enceladus experiencing at least two passages around the Milky Way
• A 3D view of dwarf galaxies with Gaia and VLT/FLAMES II. The Sextans dwarf spheroidal
• The Milky Way satellite galaxy Leo T: A perturbed cored dwarf
• A second-generation star in a relic dwarf galaxy
• The impact of rare events on the chemical enrichment in dwarf galaxies
• Carbon measurements in two ultra-faint dwarf galaxies: Grus II and Tucana IV
• Multi-component, axisymmetric dynamical models of dSphs based on distribution functions: inferences on dark matter and intermediate-mass black holes in Draco and Ursa Minor