English

A $Gaia$ EDR3 search for tidal tails in disintegrating open clusters

Astrophysics of Galaxies 2022-10-26 v2 Solar and Stellar Astrophysics

Abstract

We carry out a search for tidal tails in a sample of open clusters with known relatively elongated morphology. We identify the member stars of these clusters from the precise astrometric and deep photometric data from GaiaGaia Early Data Release 3 using the robust membership determination algorithm, ML-MOC. We identify 46 open clusters having a stellar corona beyond the tidal radius, 20 of which exhibit extended tails aligned with the cluster orbit direction in galactocentric coordinates. Notably we find NGC 6940 (at a distance of 1\sim1 kpc) is the furthest open cluster exhibiting tidal tails that are 50\sim50 pc from its center, while also identifying 40\sim40 pc long tidal tails for the nearby Pleiades. Using the minimum spanning tree length for the most massive stars relative to all cluster members, we obtain the mass segregation ratio (λMSR\rm\lambda_{MSR}) profiles as a function of the number of massive stars in each cluster. From these profiles, we can classify the open clusters into four classes based on the degree of mass segregation experienced by the clusters. We find that clusters in the most mass segregated classes are the oldest on average and have the flattest mass function slope. Of the 46 open clusters studied in this work, 41 exhibit some degree of mass segregation. Furthermore, we estimate the initial masses (Mi\rm_{i}) of these open clusters finding that some of them, having Mi104M\rm_{i}\gtrsim 10^{4} M_{\odot}, could be the dissolving remnants of Young Massive Clusters.

Keywords

Cite

@article{arxiv.2209.08259,
  title  = {A $Gaia$ EDR3 search for tidal tails in disintegrating open clusters},
  author = {Souradeep Bhattacharya and Khushboo K. Rao and Manan Agarwal and Shanmugha Balan and Kaushar Vaidya},
  journal= {arXiv preprint arXiv:2209.08259},
  year   = {2022}
}

Comments

16 pages, 15 figures, 3 tables (+8 pages, 6 figures, 1 table in Appendix), Accepted for publication at MNRAS