Current browse context:
astro-ph.SR
Change to browse by:
References & Citations
Astrophysics > Solar and Stellar Astrophysics
Title: Investigating Mass Segregation of the Binary Stars in the Open Cluster NGC 6819
(Submitted on 29 Aug 2023 (v1), last revised 21 Apr 2024 (this version, v2))
Abstract: We search for mass segregation in the intermediate-aged open cluster NGC 6819 within a carefully identified sample of probable cluster members. Using photometry from the Gaia, 2MASS, and Pan-STARRS surveys as inputs for a Bayesian statistics software suite, BASE-9, we identify a rich population of (photometric) binaries and derive posterior distributions for the cluster age, distance, metallicity and reddening as well as star-by-star photometric membership probabilities, masses and mass ratios (for binaries). Within our entire sample, we find 2632 cluster members and 777 binaries. We then select a main-sequence 'primary sample' with 14.85 < G < 19.5 containing 1342 cluster members and 250 binaries with mass ratios q > 0.5, to investigate for mass segregation. Within this primary sample, we find the binary radial distribution is significantly shifted toward the cluster center as compared to the single stars, resulting in a binary fraction that increases significantly toward the cluster core. Furthermore, we find that within the binary sample, more massive binaries have more centrally concentrated radial distributions than less massive binaries. The same is true for the single stars. We verify the expectation of mass segregation for this stellar sample in NGC 6819 through both relaxation time arguments and by investigating a sophisticated N-body model of the cluster. Importantly, this is the first study to investigate mass segregation of the binaries in the open cluster NGC 6819.
Submission history
From: Claire Zwicker [view email][v1] Tue, 29 Aug 2023 19:22:00 GMT (435kb,D)
[v2] Sun, 21 Apr 2024 20:09:24 GMT (623kb,D)
Link back to: arXiv, form interface, contact.