J/A+A/647/A19 3D Kinematics and age of OCs (Tarricq+, 2021)
3D kinematics and age distribution of the Open Cluster population.
Tarricq Y., Soubiran C., Casamiquela L., Cantat-Gaudin T., Chemin L.,
Anders F., Antoja T., Romero-Gomez M., Figueras F., Jordi C., Bragaglia A.,
Balaguer-Nunez L., Carrera R., Castro-Ginard A., Moitinho A., Ramos P.,
Bossini D.
<Astron. Astrophys. 647, A19 (2021)>
=2021A&A...647A..19T 2021A&A...647A..19T (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Clusters, open ; Space velocities ;
Radial velocities ; Stars, distances
Keywords: open clusters and associations: general -
Galaxy: kinematics and dynamics - Galaxy: disc -
stars: kinematics and dynamics
Abstract:
Open Clusters (OCs) can trace with a great accuracy the evolution of
the Galactic disk. The aim of this work is to study the kinematical
behavior of the OC population over time. We take advantage of the
latest age determinations of OCs to investigate the correlations of
the 6D phase space coordinates and orbital properties with age. We
also investigate the rotation curve of the Milky Way traced by OCs and
we compare it to that of other observational or theoretical studies.
We gathered nearly 30000 Radial Velocity (RV) measurements of OC
members from both Gaia-RVS data and ground based surveys and
catalogues. We computed the weighted mean RV, Galactic velocities and
orbital parameters of 1382 OCs. We investigated their distributions as
a function of age, and by comparison to field stars. We provide the
largest RV catalogue available for OCs, half of it based on at least 3
members. Compared to field stars, we note that OCs are not exactly on
the same arches in the radial-azimuthal velocity plane, while they
seem to follow the same diagonal ridges in the Galactic radial
distribution of azimuthal velocities. Velocity ellipsoids in different
age bins all show a clear anisotropy. The heating rate of the OC
population is similar to that of field stars for the radial and
azimuthal components but significantly lower for the vertical
component. The rotation curve drawn by our sample of clusters shows
several dips, which match the wiggles derived from non-axisymmetric
models of the Galaxy. From the computation of orbits, we obtain a
clear dependence of the maximum height and eccentricity with age.
Finally, the orbital characteristics of the sample of clusters as
shown by the action variables, follow the distribution of field stars.
The additional age information of the clusters points towards some
(weak) age dependence of the known moving groups.
Description:
In this paper, we compile mean RVs of OCs members and of OCs. Taken
advantage of OCs RVs, we derive their galactocentric both cartesian
and cylindrical velocities and orbital parameters for 1382 OCs among
which 418 OCs are part of a High Quality Sample (HQS).
orbits.dat:
Mean parameters for 1382 clusters (1379 OCs with galactocentric
cartesian and cylindrical velocities and 1315 with orbital
parameters).
rv-star.dat:
Mean RV for the member stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
orbits.dat 393 1382 Mean parameters for the clusters
(corrected version, 17-Dec-2021)
rv-stars.dat 64 23522 Mean parameters for the stars
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See also:
J/A+A/640/A1 : Portrait Galactic disc (Cantat-Gaudin+, 2020)
J/A+A/619/A155 : Open cluster kinematics with Gaia DR2 (Soubiran+, 2018)
Byte-by-byte Description of file: orbits.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Cluster Name of the cluster
19- 25 F7.2 km/s RVmean Mean Radial Velocity
27- 31 F5.2 km/s e_RVmean Standard error on RVmean
33- 35 I3 --- Nsel Number of stars used for RVmean
37- 43 F7.3 deg RAdeg [] Right Ascension (ICRS) at Ep=2015.5 (G1)
45- 51 F7.3 deg DEdeg Declination (ICRS) at Ep=2015.5 (G1)
53- 66 A14 --- Flag Indicates origin of parameters, or the
reason for their absence if missing (G1)
68- 72 F5.2 [yr] AgeNN ? Age (logt) of the cluster (G1)
74- 80 F7.1 pc DistPc ? Converted distance modulus (G1)
82- 88 F7.4 kpc Apo ? Apocentre of the cluster orbit
90- 99 F10.4 kpc s_Apo ? Standard deviation on Apocentre
101-107 F7.4 kpc Peri ? Pericentre of the cluster orbit
109-117 F9.4 kpc s_Peri ? Standard deviation on Pericentre
119-124 F6.4 --- Ecc ? Eccentricity of the cluster orbit
126-131 F6.4 --- s_Ecc ? Standard deviation on Eccentricity
133-138 F6.4 kpc Maxheight ? Maximum altitude of the cluster orbit
140-148 F9.4 kpc s_Maxheight ? Standard deviation on Max_height
150-160 F11.4 (km/s)2 Energy ? Energy of the orbit
162-177 F16.4 (km/s)2 s_Energy ? Standard deviation on Energy
179-187 F9.4 km/s vx ? Galactocentric cartesian space velocity
in X axis
189-199 F11.4 km/s s_vx ? Standard deviation on vx
201-208 F8.4 km/s vy ? Galactocentric cartesian space velocity
in Y axis
210-219 F10.4 km/s s_vy ? Standard deviation on vy
221-228 F8.4 km/s vz ? Galactocentric cartesian space velocity
in Z axis
230-239 F10.4 km/s s_vz ? Standard deviation on vz
241-249 F9.4 km/s vr ? Radial velocity in Cylindrical Galactic
system
251-258 F8.4 km/s s_vr ? Standard deviation on vr
260-268 F9.4 km/s vphi ? Azimuthal velocity in cylindrical Galactic
system
270-280 F11.4 km/s s_vphi ? Standard deviation on vphi
282-288 F7.4 kpc Rgal ? Distance from Galactic centre
290-299 F10.4 kpc s_Rgal ? Standard deviation on Rgal
301-309 F9.4 deg phi ? Azimuth in Galactocentric cylindrical
coordinates
311-317 F7.4 deg s_phi ? Standard deviation on phi
319-329 F11.4 pc Xgal ? X position in Galactocentric cartesian
coordinates
331-342 F12.4 pc s_Xgal ? Standard deviation on Xgal
344-354 F11.4 pc Ygal ? Y position in Galactocentric cartesian
coordinates
356-368 F13.4 pc s_Ygal ? Standard deviation on Ygal
370-379 F10.4 pc Zgal ? Z position in Galactocentric coordinates
381-391 F11.4 pc s_Zgal ? Standard deviation on Zgal
393 I1 --- HQS [0/1] High Quality Sample (2)
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Note (2): indicates wether the cluster is part of the HQS (G1) or not (0).
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Byte-by-byte Description of file: rv-stars.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 Gaia DR2 source ID
21- 25 F5.3 --- proba Membership probability (G1))
27- 43 A17 --- Cluster Cluster name
45- 52 F8.3 km/s RVmean Mean Radial Velocity of the star
54- 59 F6.3 km/s e_RVmean Standard error on RVmean
61- 62 I2 --- Nmeas Number of measurements used for RVmean
64 I1 --- used [0/1] Indicates if the RV of the star is
used to calculate the RV of its cluster
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Global notes:
Note (G1): Column coming from (Cantat-Gaudin+, 2020, Cat. J/A+A/640/A1).
Positions, orbits and velocities are reported here in the right-handed
coordinate frame. The sign of positions and velocities needs to be
flipped to be used in the left-handed coordinate frame.
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Acknowledgements:
Yoann Tarricq, yoann.tarricq(at)u-bordeaux.fr
Caroline Soubiran, caroline.soubiran(at)u-bordeaux.fr
Laia Casamiquela, laia.casamiquela-floriach(at)u-bordeaux.fr
History:
01-Mar-2021: on-line version
17-Dec-2021: corrected orbits.dat file (from author)
(End) Patricia Vannier [CDS] 12-Dec-2020