3D kinematic observations of stars in Galactic Centre Virtual Observatory Resource

Authors
  1. Do T.
  2. Martinez G.D.
  3. Yelda S.
  4. Ghez A.
  5. Bullock J.
  6. Kaplinghat M.,Lu J.R.
  7. Peter A.H.G.
  8. Phifer K.
  9. Published by
    CDS
Abstract

We present three-dimensional (3D) kinematic observations of stars within the central 0.5pc of the Milky Way (MW) nuclear star cluster (NSC) using adaptive optics imaging and spectroscopy from the Keck telescopes. Recent observations have shown that the cluster has a shallower surface density profile than expected for a dynamically relaxed cusp, leading to important implications for its formation and evolution. However, the true 3D profile of the cluster is unknown due to the difficulty in de-projecting the stellar number counts. Here, we use spherical Jeans modeling of individual proper motions and radial velocities to constrain, for the first time, the de-projected spatial density profile, cluster velocity anisotropy, black hole mass (M_BH_), and distance to the Galactic center (R_0_) simultaneously. We find that the inner stellar density profile of the late-type stars, {rho}(r){prop.to}r^-{gamma}^, have a power law slope {gamma}=0.05_-0.60^+0.29^, much more shallow than the frequently assumed Bahcall-Wolf slope of {gamma}=7/4. The measured slope will significantly affect dynamical predictions involving the cluster, such as the dynamical friction time scale. The cluster core must be larger than 0.5 pc, which disfavors some scenarios for its origin. Our measurement of M_BH_=5.76_-1.26_^+1.76^x10^6^M_{sun}_ and R_0_=8.92_-0.55_^+0.58^kpc is consistent with that derived from stellar orbits within 1" of Sgr A*. When combined with the orbit of S0-2, the uncertainty on R_0_ is reduced by 30% (8.46_-0.38_^+0.42^kpc). We suggest that the MW NSC can be used in the future in combination with stellar orbits to significantly improve constraints on R_0_.

Keywords
  1. milky-way-galaxy
  2. parallax
  3. spectroscopy
  4. infrared-photometry
  5. radial-velocity
Bibliographic source Bibcode
2013ApJ...779L...6D
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/779/L6
IVOA Identifier IVOID
ivo://CDS.VizieR/J/ApJ/779/L6
Document Object Identifer DOI
doi:10.26093/cds/vizier.17799006

Access

Web browser access HTML
http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/779/L6
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/779/L6
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/779/L6
IVOA Table Access TAP
http://tapvizier.cds.unistra.fr/TAPVizieR/tap
Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/779/L6/table1?
https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/779/L6/table1?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/779/L6/table1?

History

2015-06-15T12:08:25Z
Resource record created
2015-06-15T12:08:25Z
Created
2018-07-09T08:06:30Z
Updated

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr