A deep view into the nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. II. Kinematic characterization of the stellar populations

Abstract

The Sagittarius dwarf spheroidal galaxy (Sgr dSph) is in an advanced stage of disruption but still hosts its nuclear star cluster (NSC), M54, at its center. In this paper, we present a detailed kinematic characterization of the three stellar populations present in M54: young metal-rich (YMR); intermediate-age metal-rich (IMR); and old metal-poor (OMP), based on the spectra of $\sim 6500$ individual M54 member stars extracted from a large MUSE/VLT dataset. We find that the OMP population is slightly flattened with a low amount of rotation ($\sim 0.8$ km s${}^{-1}$) and with a velocity dispersion that follows a Plummer profile. The YMR population displays a high amount of rotation ($\sim 5$ km s${}^{-1}$) and a high degree of flattening, with a lower and flat velocity dispersion profile. The IMR population shows a high but flat velocity dispersion profile, with some degree of rotation ($\sim 2$ km s${}^{-1}$). We complement our MUSE data with information from \textit{Gaia DR2} and confirm that the stars from the OMP and YMR populations are comoving in 3D space, suggesting that they are dynamically bound. While dynamical evolutionary effects (e.g. energy equipartition) are able to explain the differences in velocity dispersion between the stellar populations, the strong differences in rotation indicate different formation paths for the populations, as supported by an $N$-body simulation tailored to emulate the YMR-OMP system. This study provides additional evidence for the M54 formation scenario proposed in our previous work, where this NSC formed via GC accretion (OMP) and in situ formation from gas accretion in a rotationally supported disc (YMR).

arXiv comment21 Pages, 10 figures. Accepted for publication by ApJ

References in corpus (107)

• emcee: The MCMC Hammer
• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• Gaia Data Release 2: The astrometric solution
• Adaptive spatial binning of integral-field spectroscopic data using Voronoi tessellations
• The merger that led to the formation of the Milky Way's inner stellar halo and thick disk
• The ATLAS3D project - III. A census of the stellar angular momentum within the effective radius of early-type galaxies: unveiling the distribution of Fast and Slow Rotators
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• The Stellar Cusp Around the Supermassive Black Hole in the Galactic Center
• The SAURON project -- X. The orbital anisotropy of elliptical and lenticular galaxies: revisiting the (V/sigma,epsilon) diagram with integral-field stellar kinematics
• A catalogue of masses, structural parameters and velocity dispersion profiles of 112 Milky Way globular clusters
• The ACS Virgo Cluster Survey. VIII. The Nuclei of Early-Type Galaxies
• Origin of the system of globular clusters in the Milky Way
• ULySS: A Full Spectrum Fitting Package
• The formation and assembly history of the Milky Way revealed by its globular cluster population
• A Disk of Young Stars at the Galactic Center as Determined by Individual Stellar Orbits
• Multiple Stellar Populations in the Globular Cluster omega Centauri as Tracers of a Merger Event
• Formation of omega Centauri from an ancient nucleated dwarf galaxy in the young Galactic disc
• Chemical Abundances for 855 Giants in the Globular Cluster Omega Centauri (NGC 5139)
• An HST Census of Nuclear Star Clusters in Late-Type Spiral Galaxies: I. Observations and Image Analysis
• The Kinematics, Orbit, and Survival of the Sagittarius Dwarf Spheroidal Galaxy
• Stellar Populations in the Central 0.5 pc of the Galaxy II: The Initial Mass Function
• The dynamical distance and intrinsic structure of the globular cluster omega Centauri
• Velocity Dispersion Profiles of Seven Dwarf Spheroidal Galaxies
• Proper motions and dynamics of the Milky Way globular cluster system from Gaia DR2
• Evidence for Warped Disks of Young Stars in the Galactic Center
• A Supermassive Black Hole in an Ultracompact Dwarf Galaxy
• An Intermediate-Mass Black Hole in the Globular Cluster G1: Improved Significance from New Keck and Hubble Space Telescope Observations
• Spiral galaxies with WFPC2: II. The Nuclear Properties of 40 objects
• Masses of star clusters in the nuclei of bulge-less spiral galaxies
• Gemini and Hubble Space Telescope Evidence for an Intermediate Mass Black Hole in omega Centauri
• Detailed abundances of a large sample of giant stars in M 54 and in the Sagittarius nucleus
• The nucleus of the Sagittarius dSph galaxy and M54: a window on the process of galaxy nucleation
• A HST Census of Nuclear Star Clusters in Late-Type Spiral Galaxies: II. Cluster Sizes and Structural Parameter Correlations
• The ACS Survey of Galactic Globular Clusters: M54 and Young Populations in the Sagittarius Dwarf Spheroidal Galaxy
• A stellar census in globular clusters with MUSE: The contribution of rotation to cluster dynamics studied with 200 000 stars
• N-body modeling of globular clusters: Masses, mass-to-light ratios and intermediate-mass black holes
• Coude-feed stellar spectral library - atmospheric parameters
• The AIMSS Project I: Bridging the Star Cluster - Galaxy Divide
• Unveiling a Rich System of Faint Dwarf Galaxies in the Next Generation Fornax Survey
• Properties of the Remnant Clockwise Disk of Young Stars in the Galactic Center
• Nuclear star clusters in 228 spiral galaxies in the HST/WFPC2 archive: catalogue and comparison to other stellar systems
• Hubble Space Telescope Proper Motion (HSTPROMO) Catalogs of Galactic Globular Clusters. I. Sample Selection, Data Reduction and NGC 7078 Results
• Families of dynamically hot stellar systems over ten orders of magnitude in mass
• Performance Analysis of Direct N-Body Algorithms on Special-Purpose Supercomputers
• The Streams of the Gaping Abyss: A population of entangled stellar streams surrounding the Inner Galaxy
• Clues to Nuclear Star Cluster Formation from Edge-on Spirals
• The Ital-FLAMES survey of the Sagittarius dwarf Spheroidal galaxy. I. Chemical abundances of bright RGB stars
• Rotation and anisotropy of galaxies revisited
• Hubble Space Telescope proper motion (HSTPROMO) catalogs of Galactic globular clusters. II. Kinematic profiles and maps
• The ACS Fornax Cluster Survey. VI. The Nuclei of Early-Type Galaxies in the Fornax Cluster
• Large scale kinematics and dynamical modelling of the Milky Way nuclear star cluster
• M 54 + Sagittarius = omega Centauri
• The Next Generation Virgo Cluster Survey. XXIII. Fundamentals of nuclear star clusters over seven decades in galaxy mass
• Nearby Early-Type Galactic Nuclei at High Resolution: Dynamical Black Hole and Nuclear Star Cluster Mass Measurements
• Ultra compact dwarf galaxy formation by tidal stripping of nucleated dwarf galaxies
• The internal rotation of globular clusters revealed by Gaia DR2
• SAPPORO: A way to turn your graphics cards into a GRAPE-6
• No Energy Equipartition in Globular Clusters
• The HST/ACS Coma Cluster Survey. X. Nuclear star clusters in low-mass early-type galaxies: scaling relations
• The HST large programme on $\omega$ Centauri - II. internal kinematics
• Stellar populations and star formation histories of the nuclear star clusters in six nearby galaxies
• Rotating Globular Clusters
• Contribution of stripped nuclear clusters to globular cluster and ultra-compact dwarf galaxy populations
• Kinematic signature of an intermediate-mass black hole in the globular cluster NGC 6388
• Na-O anticorrelation and HB. IX. Kinematics of the program clusters. A link between systemic rotation and HB morphology?
• The eye of Gaia on globular clusters kinematics: internal rotation
• Measuring Consistent Masses for 25 Milky Way Globular Clusters
• A Tail of Two Populations: Chemo-dynamics of the Sagittarius Stream and Implications for its Original Mass
• KMOS view of the Galactic Centre I. Young stars are centrally concentrated
• A novel look at energy equipartition in globular clusters
• Improved Dynamical Constraints on the Mass of the central Black Hole in NGC 404
• Density and kinematic cusps in M54 at the heart of the Sagittarius dwarf galaxy: evidence for a 10^4 M_sun Black Hole?
• The metallicity spread and the age-metallicity relation of Omega Centauri
• Central rotations of Milky Way Globular Clusters
• Exploring Halo Substructure with Giant Stars: Substructure in the Local Halo as Seen in the Grid Giant Star Survey Including Extended Tidal Debris from Omega Centauri
• Multiple populations in globular clusters: the distinct kinematic imprints of different formation scenarios
• The Structure of Nuclear Star Clusters in Nearby Late-type Spiral Galaxies from Hubble Space Telescope Wide Field Camera 3 Imaging
• On the rotation of nuclear star clusters formed by cluster-inspirals
• The State-of-the-Art HST Astro-Photometric Analysis of the core of ωCentauri. III. The Main Sequence's Multiple Populations Galore
• Chemical abundances in the nucleus of the Sagittarius dwarf spheroidal galaxy
• A deep view into the nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. I. Data and stellar population characterization
• The non-peculiar velocity dispersion profile of the stellar system omega Centauri
• Differences in the rotational properties of multiple stellar populations in M 13: a faster rotation for the "extreme" chemical subpopulation
• The extended star formation history of omega Centauri
• The Gaia-ESO Survey: Kinematics of seven Galactic globular clusters
• The HST Large Program on Omega Centauri. I. Multiple stellar populations at the bottom of the main sequence probed in NIR-Optical
• Evolution of second generation stars in stellar disks of globular and nuclear clusters: Omega Centauri as a test case
• A Dynamical N-body Model for the Central Region of $\omega$ Centauri
• A VLT/FLAMES study of the peculiar intermediate-age Large Magellanic Cloud star cluster NGC 1846 - I. Kinematics
• Are Globular Clusters the Remnant Nuclei of Progenitor Disk Galaxies?
• A critical look at the merger scenario to explain multiple populations and rotation in iron-complex globular clusters
• The Sagittarius dwarf galaxy: Where did all the gas go?
• The impact of stripped Nuclei on the Super-Massive Black Hole number density in the local Universe
• The ACS Survey of Galactic Globular Clusters XI: The Three-Dimensional Orientation of the Sagittarius Dwarf Spheroidal Galaxy and its Globular Clusters
• Discovery of a Dynamical Cold Point in the Heart of the Sagittarius dSph Galaxy with Observations from the APOGEE Project
• Second generation stellar disks in Dense Star Clusters and cluster ellipticities
• A Tale Twice Told: The Luminosity Profiles of the Sagittarius Tails
• Exploring the outskirts of globular clusters: the peculiar kinematics of NGC 3201
• The orbital anisotropy profiles of nearby globular clusters from Gaia Data Release 2
• Mergers, tidal interactions, and mass exchange in a population of disc globular clusters
• The complex kinematics of rotating star clusters in a tidal field
• Mergers, tidal interactions, and mass exchange in a population of disc globular clusters: II. Long-term evolution
• A Model for Clumpy Self-Enrichment in Globular Clusters
• Mergers of multi-metallic globular clusters: The role of dynamics
• Star formation at the Galactic Centre: coevolution of multiple young stellar discs
• Kinematics of outer halo globular clusters: M 75 and NGC 6426

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• Gaia EDR3 view on Galactic globular clusters
• Nuclear Star Clusters
• The last breath of the Sagittarius dSph
• The Accreted Nuclear Clusters of the Milky Way
• On the origin of a rotating metal-poor stellar population in the Milky Way Nuclear Cluster
• oMEGACat I: MUSE spectroscopy of 300,000 stars within the half-light radius of $\omega$ Centauri
• MgAl burning chain in Omega Centauri
• oMEGACat III. Multi-band photometry and metallicities reveal spatially well-mixed populations within $\omega$ Centauri's half-light radius
• Hunting for intermediate-mass black holes in globular clusters: an astrometric study of NGC 6441
• The Rotation of Selected Globular Clusters and the Differential Rotation of M3 in Multiple Populations from the SDSS-IV APOGEE-2 Survey
• oMEGACat II -- Photometry and proper motions for 1.4 million stars in Omega Centauri and its rotation in the plane of the sky
• The metallicity distribution in the core of the Sagittarus dwarf spheroidal: minimising the metallicity biases
• Recovering age-metallicity distributions from integrated spectra: validation with MUSE data of a nearby nuclear star cluster
• A Deep View into the Nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. III. Discrete multi-component population-dynamical models based on the Jeans equations
• Abundance ties: Nephele and the globular cluster population accreted with $\omega$ Cen. Based on APOGEE DR17 and Gaia EDR3
• Testing for Dark Matter in the Outskirts of Globular Clusters
• The Pristine Inner Galaxy Survey (PIGS) IV: A photometric metallicity analysis of the Sagittarius dwarf spheroidal galaxy
• oMEGACat. VI. Analysis of the overall kinematics of Omega Centauri in 3D: velocity dispersion, kinematic distance, anisotropy, and energy equipartition
• The Dark Matter Halo of M54
• Spatially Resolving the Star Formation Histories of Three Nearby Nuclear Star Clusters
• Signature of systemic rotation in 21 Galactic Globular Clusters from APOGEE-2
• Driving factors behind multiple populations
• Black Hole Scaling Relations in the Dwarf-galaxy Regime with $Gaia$-Sausage/Enceladus and $\omega$Centauri
• Uncertainty-Aware Blob Detection with an Application to Integrated-Light Stellar Population Recoveries
• Introducing a new multi-particle collision method for the evolution of dense stellar systems. Crash-test N-body simulations
• Kinematics of metallicity populations in Omega Centauri using Gaia Focused Product Release and Hubble Space Telescope
• Nuclear star clusters as probes of dark matter halos: the case of the Sagittarius Dwarf Spheroidal Galaxy
• Chemical tagging with APOGEE, MUSE, and HST: constraints on the formation of $\omega$ Centauri
• Galaxy mass dependence of metal-enrichment of nuclear star clusters
• Resolved nuclear kinematics link the formation and growth of nuclear star clusters with the evolution of their early and late-type hosts