Two Populations of Open Star Clusters in the Galaxy

Abstract

Based on our compiled catalogue of fundamental astrophysical parameters for 593 open clusters, we analyze the relations between the chemical composition, spatial positions, Galactic orbital elements, age, and other physical parameters of open star clusters. We show that the population of open clusters is heterogeneous and is divided into two groups differing by their mean parameters, properties, and origin. One group includes the Galactic clusters formed mainly from the interstellar matter of the thin disk with nearly solar metallicities ([Fe/H] > -0.2) and having almost circular orbits a short distance away from the Galactic plane, i.e., typical of the field stars of the Galactic thin disk. The second group includes the peculiar clusters formed through the interaction of extragalactic objects (such as high--velocity clouds, globular clusters, or dwarf galaxies) with the interstellar matter of the thin disk, which, as a result, derived abnormally low (for field thin-disk stars) metallicities and/or Galactic orbits typical of objects of the older Galactic subsystems.

arXiv comment15 pages, 4 figures

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Cited by in corpus (10)

• Heterogeneity of the Population of Open Star Clusters in the Galaxy
• New insights in the origin and evolution of the old, metal-rich open cluster NGC 6791
• On the Origin of High-Altitude Open Clusters in the Milky Way
• On the Survival of High-Altitude Open Clusters within the Milky Way Galaxy Tides
• NGC 1252: a high altitude, metal poor open cluster remnant
• Gravitational interactions between globular and open clusters: an introduction
• Young Open Star Clusters: The Spatial Distribution of Metallicity in the Solar Neighborhood
• Peculiarities of α-element abundances in Galactic open clusters
• Peculiarities of the abundances of neutron-capture elements in Galactic open clusters
• On the Metallicity Gradient in the Galactic Disk