Kinematic substructure in star clusters constrains star cluster formation

Arnold, Becky; Wright, Nicholas J

Abstract

The spatial-kinematic structure of 48 young star clusters and associations is investigated. Moran’s I statistic is used to quantify the degree of kinematic substructure in each region, and the results are compared to those expected assuming the hierarchical or monolithic models of star cluster formation. Of the observed regions, 39 are found to have significant kinematic substructure, such that they are compatible with the hierarchical model and incompatible with the monolithic model. This includes multiple regions whose Q parameter shows the region to be centrally concentrated and clustered. The remaining nine are compatible with both models. From this it is concluded that the kinematic substructure of the observed star clusters represents strong evidence in favour the hierarchical model of star cluster formation over the monolithic model.

Citation

Arnold, B., & Wright, N. J. (2024). Kinematic substructure in star clusters constrains star cluster formation. Monthly Notices of the Royal Astronomical Society, 531(1), 1191–1202. https://doi.org/10.1093/mnras/stae1236

• Journal Article Type: Article
• Acceptance Date: May 7, 2024
• Online Publication Date: May 11, 2024
• Publication Date: 2024-06
• Deposit Date: May 28, 2024
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 531
• Issue: 1
• Pages: 1191–1202
• DOI: https://doi.org/10.1093/mnras/stae1236
• Keywords: methods: statistical – stars: formation – stars: kinematics and dynamics – open clusters and associations: general
• Public URL: https://keele-repository.worktribe.com/output/833150
• Publisher URL: https://academic.oup.com/mnras/article/531/1/1191/7670615?login=true