2019/12/13 by Yu Zhang, Shih-Yun Tang, W. P. Chen +2 · 1 citation
Physics and Astronomy · #astro-ph.GA #astro-ph.SR
paper · pdf · doi:10.3847/1538-4357/ab63d4
16 pages, 13 figures, accepted by ApJ
arxiv created 2019/12/13 · arxiv updated 2020/02/12
We present the stellar population, using \it Gaia DR2 parallax, kinematics, and photometry, of the young (∼ 100~Myr), nearby (∼ 230~pc) open cluster, Blanco1. A total of 644 member candidates are identified via the unsupervised machine learning method StarGO to find the clustering in the 5-dimensional position and proper motion parameter (X, Y, Z, μαcosδ, μδ) space. Within the tidal radius of 10.0 ± 0.3~pc, there are 488 member candidates, 3 times more than those outside. A leading tail and a trailing tail, each of 50--60~pc in the Galactic plane, are found for the first time for this cluster, with stars further from the cluster center streaming away faster, manifest stellar stripping. Blanco1 has a total detected mass of 285±32~M_\odot with a mass function consistent with a slope of α=1.35±0.2 in the sense of dN/dm ∝ m-α, in the mass range of 0.25--2.51~M_\odot , where N is the number of members and m is stellar mass. A Minimum Spanning Tree (Λ\rm MSR) analysis shows the cluster to be moderately mass segregated among the most massive members (\gtrsim 1.4~M_\odot), suggesting an early stage of dynamical disintegration.