Kinematics of the old stellar population at the Galactic Center

Abstract

We aim at a detailed description of the kinematic properties of the old, (several Gyrs) late-type CO-absorption star population among the Galactic centre (GC) cluster stars. We applied AO-assisted, near-infrared imaging and integral-field spectroscopy using the instruments NAOS/CONICA and SINFONI at the VLT. We obtained proper motions for 5445 stars, 3D velocities for 664 stars, and acceleration limits (in the sky plane) for 750 stars. We detect for the first time significant cluster rotation in the sense of the general Galactic rotation in proper motions. Out of the 3D velocity dispersion, we derive an improved statistical parallax for the GC of R0 = 8.07 +/- 0.32 (stat) +/- 0.13 (sys) kpc. The distribution of 3D stellar speeds can be approximated by local Maxwellian distributions. Kinematic modelling provides deprojected 3D kinematic parameters, including the mass profile of the cluster. We find an upper limit of 4% for the amplitude of fluctuations in the phase-space distribution of the cluster stars compared to a uniform, spherical model cluster. Using upper limits on accelerations, we constrain the minimum line-of-sight distances from the plane of SgrA* of five stars located within the innermost few (projected) arcsec. The stars within 0.7'' radius from the star group IRS13E do not co-move with this group, making it unlikely that IRS13E is the core of a substantial star cluster. Overall, the GC late-type cluster is described well as a uniform, isotropic, rotating, dynamically relaxed, phase-mixed system.

23 pages, 20 figures, accepted by A&A. This versions corresponds to the one to be printed. Some language editing done, one figure in Sect. 5.6 replaced by a table, a few bugs and typos corrected

References in corpus (11)

• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• The structure of the nuclear stellar cluster of the Milky Way
• Ground-Based CCD Astrometry with Wide Field Imagers. I. [Observations just a few years apart allow decontamination of field objects from members in two Globular clusters.]
• NMAGIC: Fast Parallel Implementation of a Chi-Squared-Made-to-Measure Algorithm for Modelling Observational Data
• Ground-based CCD astrometry with wide field imagers. II. A star catalogue for M67: [email protected] MPG/ESO astrometry, FLAMES@VLT radial velocities
• Evidence for a Long-Standing Top-Heavy IMF in the Central Parsec of the Galaxy
• The distance to the Galactic Centre based on Population-II Cepheids and RR Lyrae stars
• Re-visiting the relations: Galactic thin disc age-velocity dispersion relation
• Hypervelocity Stars III. The Space Density and Ejection History of Main Sequence Stars from the Galactic Center
• LMC origin of the hyper-velocity star HE 0437-5439. Beyond the supermassive black hole paradigm
• Low Metallicity Indicates that the Hypervelocity Star HE 0437-5439 was Ejected from the LMC

Cited by in corpus (37)

• The old nuclear star cluster in the Milky Way: dynamics, mass, statistical parallax, and black hole mass
• Large scale kinematics and dynamical modelling of the Milky Way nuclear star cluster
• Dynamical evolution of the young stars in the Galactic center: N-body simulations of the S-stars
• The nuclear cluster of the Milky Way: Our primary testbed for the interaction of a dense star cluster with a massive black hole
• SPHERE IRDIS and IFS astrometric strategy and calibration
• The young stars in the Galactic Center
• Clustering of Local Group distances: publication bias or correlated measurements? IV. The Galactic Center
• Detailed Abundances for the Old Population near the Galactic Center: I. Metallicity distribution of the Nuclear Star Cluster
• Revealing the Formation of the Milky Way Nuclear Star Cluster via Chemo-Dynamical Modeling
• Analysis of Determinations of the Distance between the Sun and the Galactic Center
• The Galactic Center as a laboratory for theories of gravity and dark matter
• Circumstellar discs in Galactic centre clusters: Disc-bearing B-type stars in the Quintuplet and Arches clusters
• Formation of Dark Matter Torii Around Supermassive Black Holes Via The Eccentric Kozai-Lidov Mechanism
• A three-dimensional map of the Milky Way using 66,000 Mira variable stars
• Precise Dynamical Masses of Epsilon Indi Ba and Bb: Evidence of Slowed Cooling at the L/T Transition
• Milky Way White Dwarfs as Sub-GeV to Multi-TeV Dark Matter Detectors
• A proper motion catalogue for the Milky Way's nuclear stellar disc
• Spin Evolution of Supermassive Black Holes and Galactic Nuclei
• Stellar Populations in the Central 0.5 pc of Our Galaxy III: The Dynamical Sub-structures
• Kinematic data rebuild the Nuclear star cluster as the most metal rich region of the Galaxy
• Constraints on the Galactic Centre environment from \textit{Gaia} hypervelocity stars III: Insights on a possible companion to Sgr A*
• 2D kinematic study of the central region of NGC 4501
• Smooth kinematic and metallicity gradients reveal that the Milky Way's nuclear star cluster and disc might be part of the same structure
• Sculpting the Stellar Cusp in the Galactic Center
• Dynamical mass distribution and velocity structure of the Galactic centre
• Parameter Distributions of Binary Black Hole Mergers Near Supermassive Black Holes as Seen by Advanced Gravitational Wave Detectors
• Probing the formation of planetesimals in the Galactic Centre using Sgr A* flares
• Study of the Science Capabilities of PRIMA in the Galactic Center
• The Earliest Stage of Galactic Star Formation
• Long-period maser-bearing Miras in the Galactic center: period-luminosity relations and extinction estimates
• Observations of the 86 GHz SiO maser sources in the Central Parsec of the Galactic Centre
• 3D Kinematics of Stellar SiO Masers in the Galactic Center
• The Near-Infrared Spectrum of the Nuclear Star Cluster: Looking Below the Tip of the Iceberg and Comparisons with Extragalactic Nuclei
• Post-Keplerian perturbations of the hyperbolic motion in the field of a rotating massive object. Analysis in terms of osculating and nonosculating (contact) elements
• Lessons learned from SPHERE for the astrometric strategy of the next generation of exoplanet imaging instruments
• Self-consistent modelling of the Milky Way's Nuclear Stellar Disc
• Dips in the sub-TeV gamma-ray light curves from central parts of galaxies due to transiting luminous stars