J/MNRAS/484/2832 Proper motions of Milky Way globular clusters (Vasiliev, 2019)
Proper motions and dynamics of the Milky Way globular cluster system from
Gaia DR2.
Vasiliev E.
<Mon. Not. R. Astron. Soc. 484, 2832-2850 (2019)>
=2019MNRAS.484.2832V 2019MNRAS.484.2832V (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Clusters, globular ; Proper motions ;
Radial velocities
Keywords: catalogues - proper motions - globular clusters: general -
Galaxy: kinematics and dynamics
Abstract:
We use Gaia Data Release 2 to determine the mean proper motions for
150 Milky Way globular clusters (almost the entire known population),
with a typical uncertainty of 0.05mas/yr limited mainly by
systematic errors. Combining them with distance and line-of-sight
velocity measurements from the literature, we analyse the distribution
of globular clusters in the 6D phase space, using both
position/velocity and action/angle coordinates. The population of
clusters in the central 10kpc has a mean rotational velocity reaching
50-80km/s, and a nearly isotropic velocity dispersion 100-120km/s,
while in the outer galaxy, the cluster orbits are strongly radially
anisotropic. We confirm a concentration of clusters at high radial
action in the outer region of the Galaxy. Finally, we explore a range
of equilibrium distribution function-based models for the entire
globular cluster system, and the information they provide about the
potential of the Milky Way. The dynamics of clusters is best described
by models with the circular velocity between 10 and 50kpc staying in
the range 210-240km/s.
Description:
The catalogue of mean proper motions of 150 Milky Way globular
clusters, derived from the Gaia data release 2 astrometry. The
uncertainties take into account the spatially correlated systematic
errors in Gaia and are at the level 0.05mas/yr for most clusters. The
measurement procedure also produces the list of member stars and the
spatial scale of their distribution (Rscale). The entire catalogue,
including the list of members and the galactic orbits of clusters, may
be reconstructed with the Python program available at this URL:
https://github.com/GalacticDynamics-Oxford/GaiaTools For convenience,
the additional columns provide the quantities taken from the
literature: distances from the Harris (2010arXiv1012.3224H 2010arXiv1012.3224H) catalogue,
and line-of-sight velocities from Baumgardt, Hilker, Sollima & Bellini
(2019, Cat. J/MNRAS/482/5138).
Parallaxes and proper motions derived from Gaia DR2 are superseded
by data derived from Gaia EDR3 in Vasiliev & Baumgardt,
2021MNRAS.505.5978V 2021MNRAS.505.5978V, Cat. J/MNRAS/505/5978
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 119 150 The catalogue of cluster proper motions (table C1).
See update with Gaia EDR3 in J/MNRAS/505/5978
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/616/A12 : Gaia DR2 sources in GC and dSph (Gaia Collaboration+, 2018)
J/MNRAS/482/5138 : Galactic GC proper motions & velocities (Baumgardt+, 2019)
J/MNRAS/505/5978 : Gaia EDR3 view on Galactic globular clusters
(Vasiliev+, 2021)
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Common name, NGC identifier, etc.
13- 22 A10 --- OName Other name
25- 31 F7.3 deg RAdeg Right Ascension J2000
33- 39 F7.3 deg DEdeg Declination J2000
43- 47 F5.1 kpc Dist ? Distance to the cluster
(from Harris, 2010arXiv1012.3224H 2010arXiv1012.3224H)
49- 55 F7.2 km/s HRV Line-of-sight velocity (from Baumgardt et al.,
2019, Cat. J/MNRAS/482/5138)
59- 63 F5.2 km/s e_HRV Uncertainty in line-of-sight velocity
65- 71 F7.3 mas/yr pmRA Proper motion in right ascension, pmRA*cosDE
73- 79 F7.3 mas/yr pmDE Proper motion in declination
83- 87 F5.3 mas/yr e_pmRA Uncertainty (including systematic) in pmRA
91- 95 F5.3 mas/yr e_pmDE Uncertainty (including systematic) in pmDE
98-103 F6.3 --- corr Correlation coefficient between uncertainties
108-111 F4.1 arcmin Rscale Scale radius of Gaia-detected cluster members
115-119 I5 --- Nstar Number of Gaia-detected cluster member stars
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Acknowledgements:
Eugene Vasiliev, eugvas(at)lpi.ru
(End) E. Vasiliev [Inst. Astronomy, Cambridge, UK], P. Vannier [CDS] 11-Feb-2019