Radial Velocities of Three Poorly Studied Clusters and the Kinematics of Open Clusters

Abstract

We present radial velocities for stars in the field of the open star clusters Berkeley 44, Berkeley 81, and NGC 6802 from spectra obtained using the Wisconsin-Indiana-Yale-NOAO (WIYN) 3.5 m telescope. These clusters are of intermediate age (1-3 Gyr), located within the solar Galactocentric radius, and have no previous radial velocity measurements. We find mean radial velocities of -9.6 +/- 3.0 km s^-1, 48.1 +/- 2.0 km s^-1, and 12.4 +/- 2.8 km s^-1 for Be 44, Be 81, and NGC 6802, respectively. We present an analysis of radial velocities of 134 open clusters of a wide range of ages using data obtained in this study and the literature. Assuming the system of clusters rotates about the Galactic center with a constant velocity, we find older clusters exhibit a slower rotation and larger line-of-sight (LOS) velocity dispersion than younger clusters. The gradual decrease in rotational velocity of the cluster system with age is accompanied by a smooth increase in LOS velocity dispersion, which we interpret as the effect of heating on the open cluster system over time.

References in corpus (58)

• Cosmic-Ray Rejection by Laplacian Edge Detection
• Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits
• The Geneva-Copenhagen survey of the Solar neighbourhood: Ages, metallicities, and kinematic properties of 14,000 F and G dwarfs
• The Geneva-Copenhagen Survey of the Solar neighbourhood III. Improved distances, ages, and kinematics
• The Geneva-Copenhagen Survey of the Solar neighbourhood II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk
• Elemental Abundance Ratios in Stars of the Outer Galactic Disk. I. Open Clusters
• Chemical abundance analysis of the Open Clusters Cr110, NGC2099 (M37), NGC2420, NGC7789 and M67 (NGC2682)
• Metal Abundances of Red Clump Stars in Open Clusters: I. NGC 6819
• Elemental Abundance Ratios in Stars of the Outer Galactic Disk. IV. A New Sample of Open Clusters
• Old open clusters in the outer Galactic disk
• A Chemical Abundance Study of 10 Open Clusters Based on WIYN-Hydra Spectroscopy
• The Star Formation History and Mass Function of the Double Cluster h and Chi Persei
• WIYN Open Cluster Study XXXII: Stellar Radial Velocities in the Old Open Cluster NGC 188
• The orbits of open clusters in the Galaxy
• Wide Field CCD photometry around nine open clusters
• Detailed analysis of open clusters: a mass function break and evidence of a fundamental plane
• CCD BV survey of 42 open clusters
• A High Relative-Precision Color-Magnitude Diagram of M67
• The CFHT Open Star Cluster Survey. III. The White Dwarf Cooling Age of the Rich Open Star Cluster NGC 2099 (M37)
• Metal abundances in extremely distant Galactic old open clusters. I. Berkeley 29 and Saurer 1
• Star Clusters in the Galactic Anticenter Stellar Structure and the Origin of Outer Old Open Clusters
• The Distances to Open Clusters from Main-Sequence Fitting. IV. Galactic Cepheids, the LMC, and the Local Distance Scale
• The intermediate-age open cluster NGC 2158
• A New Look at the Old Star Cluster NGC 6791
• Photometric study of the young open cluster NGC 3293
• High-resolution spectroscopy of the old open cluster Collinder 261:abundances of Iron and other elements
• The Open Cluster NGC 7789: II. CCD VI Photometry
• The origin and orbit of the old, metal-rich, open cluster NGC 6791: Insights from kinematics
• Element abundances in the metal rich open cluster NGC6253
• The absolute motion of the peculiar cluster NGC6791
• Open clusters towards the Galactic center: chemistry and dynamics. A VLT spectroscopic study of NGC6192, NGC6404, NGC6583
• Metal abundances in extremely distant Galactic old open clusters. II. Berkeley 22 and Berkeley 66
• CCD photometry of the old open cluster Collinder 261
• BVI photometry of the very old open cluster Berkeley 17
• Berkeley 29, the most distant old open cluster
• Photometric and kinematic studies of open star clusters. III. NGC 4103, NGC 5281, and NGC 4755
• Photometry and Spectroscopy of Old, Outer Disk Star Clusters: vdB-Hagen 176, Berkeley 29 and Saurer 1
• The IMF of open star clusters with Tycho-2
• The intermediate age open cluster NGC 2660
• Photometric and spectroscopic study of the intermediate age open cluster NGC 3960
• A photometric study of the old open clusters Berkeley 73, Berkeley 75 and Berkeley 25
• NGC 1817, NGC 2141, and Berkeley 81: three BOCCE clusters of intermediate age
• The old open cluster NGC 2112: updated estimates of fundamental parameters based on a membership analysis
• Old open clusters: the interesting case of Berkeley 21
• CCD photometric search for peculiar stars in open clusters. VIII. King 21, NGC 3293, NGC 5999, NGC 6802, NGC 6830, Ruprecht 44, Ruprecht 115, and Ruprecht 120
• An optical and near IR study of the old open cluster NGC 2141
• BVRIJHK photometry and proper motion analysis of NGC 6253 and the surrounding field
• The old open clusters Saurer A, B and C revisited
• Fundamental parameters of six neglected old open clusters
• The intermediate-age open clusters Ruprecht 4, Ruprecht 7 and Pismis 15
• Trumpler 20 - an old and rich open cluster
• The anticenter old open cluster NGC 1883: radial velocity and metallicity
• uvby-Hbeta CCD photometry and membership segregation of the open cluster NGC 2548; Gaps in the Main Sequence of open clusters
• Pre-main sequence stars in open clusters. I. The DAY-I catalogue
• Proper Motions and CCD-photometry of Stars in the Region of the Open Cluster Trumpler 2
• NGC 1883: a neglected intermediate-age open cluster located in the outskirts of the Galactic disk
• UBVI CCD Photometry of the Old Open Cluster NGC 1193
• The open cluster NGC 6520 and the nearby dark molecular cloud Barnard 86

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• The Gaia-ESO Survey: Sodium and aluminium abundances in giants and dwarfs - Implications for stellar and Galactic chemical evolution
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• The Gaia-ESO Survey: Insights on the inner-disc evolution from open clusters
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