Statistical analysis of dynamical evolution of open clusters

Abstract

We present the dynamical evolution of 10 open clusters, which were part of our previous studies. These clusters include both young and intermediate-age open clusters with ages ranging from \(25 \pm 19\) Myr to \(1.78\pm 0.20\) Gyr. The total mass of these clusters ranges from \(356.18\pm 142.90\) to \(1811.75\pm ~901.03\) \(M_{\odot }\). The Galactocentric distances to the clusters are in the range of \(8.91\pm 0.02\)–\(11.74\pm 0.18\) kpc. The study is based on the ground-based UBVRI data supplemented by the astrometric data from the Gaia archive. We studied the minimum spanning tree of the member stars for these clusters. The mass segregation in these clusters was quantified by mass segregation ratios calculated from the mean edge length obtained through the minimum spanning tree. The clusters NGC 2360, NGC 1960, IC 1442, King 21 and SAI 35 have \(\Gamma _\textrm{MSR}\) to be \(1.65\pm 0.18\), \(1.94\pm 0.22\), \(2.21\pm 0.20\), \(1.84\pm 0.23\) and \(1.96\pm 0.25\), respectively, which indicate moderate mass segregation in these clusters. The remaining five clusters are found to exhibit weak or no mass segregation. We used the ratio of half mass radius to the tidal radius i.e., \(R_{h}/R_{t}\) to investigate the effect of the tidal interactions on the cluster structure and dynamics. The ratios of half mass radii to tidal radii are found to be positively correlated with the Galactocentric distances with a linear slope of \(0.06\pm 0.01\) having linear regression coefficient r-square \(=\) 0.93 for the clusters.