Open clusters: their kinematics and metellicities

TL;DR

This paper reviews recent work on Galactic open clusters, analyzing their spatial, metallicity, and kinematic properties, and introduces the upcoming LAMOST Open Cluster Survey to enhance such studies.

Contribution

It presents new statistical analysis of open cluster metallicities and kinematics, and proposes the large-scale LOCS survey utilizing LAMOST for detailed cluster studies.

Findings

Derived a radial metallicity gradient of -0.058 dex/kpc.

Found evidence of mass segregation in young clusters.

Indicated the disk abundance gradient was steeper in the past.

Abstract

We review our work on Galactic open clusters in recent years, and introduce our proposed large program for the LOCS (LAMOST Open Cluster Survey). First, based on the most complete open clusters sample with metallicity, age and distance data as well as kinematic information, some preliminary statistical analysis regarding the spatial and metallicity distributions is presented. In particular, a radial abundance gradient of - 0.058$\pm$ 0.006 dex kpc$^{-1}$ was derived, and by dividing clusters into age groups we show that the disk abundance gradient was steeper in the past. Secondly, proper motions, membership probabilities, and velocity dispersions of stars in the regions of two very young open clusters are derived. Both clusters show clear evidence of mass segregation, which provides support for the ``primordial'' mass segregation scenarios. Based on the great advantages of the forthcoming LAMOST facility, we have proposed a detailed open cluster survey with LAMOST (the LOCS). The aim, feasibility, and the present development of the LOCS are briefly summarized.